Author Topic: Question! and Help I need to build a v8 engine servo motor governor  (Read 26846 times)

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Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #180 on: December 30, 2009, 06:07:05 PM »
Hi Soeren
Quote
Did you try it?

Yes but no luck on stopping the ripple or jitterypulses.

Quote
The mechanical movement of the servo should probably be translated to a rather small movement of the gas "pedal", to get the finest possible control.

That's what I was hoping you would say as it appears the this S3003 servo seems to stabilize in a very tight PW.

I am currently tracing down the 2.3 section of the circuit somethings is not flipping and flopping so to speak as it should, when taking a trace of set and reset the reset signal inverts or colapses just with very little freq change. But the set signal is steady as a rock. I'm not sure yet what is going on.

More than likely a wire out of place as you have noticed the wonderful spaghetti board ;D

Nice to hear from you again and soon NEWYEAR, I think Johnny Walker and the Crown Royals and MR. Jack D and the Bubbles may stop in for a few....  ;) :P
UPDATE 

Johnny is coming early like tonight as this PASTA BOWL CIRCUIT IS RIPPIN MY LAST NERVE :o

Just so you know I think we are reaching a point that loose connections and wires everywhere that is becoming almost impossible to get it stable. If I bump anything it can throw it into a state of search for long periods to find it.

I believe I am going to have to attempt and start hard wiring to stabilize the circuits.

What is your thoughts regarding this. as I am wasting tons of time chasing 1 loose connection.   :-\ :P
« Last Edit: December 30, 2009, 09:26:57 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #181 on: December 31, 2009, 11:56:03 AM »
Hi Neil,


Yes but no luck on stopping the ripple or jitterypulses.
OK, perhaps we should save this for when the stability of the rest of the circuit is restored.


Quote
The mechanical movement of the servo should probably be translated to a rather small movement of the gas "pedal", to get the finest possible control.

That's what I was hoping you would say as it appears the this S3003 servo seems to stabilize in a very tight PW.
What do you mean? Doesn't it travel the full 180°?


I am currently tracing down the 2.3 section of the circuit somethings is not flipping and flopping so to speak as it should, when taking a trace of set and reset the reset signal inverts or colapses just with very little freq change. But the set signal is steady as a rock. I'm not sure yet what is going on.

More than likely a wire out of place as you have noticed the wonderful spaghetti board ;D
The signal (input) to 2.3 should be within the range that C1 (TP11) covers, or one of them has to be modified (don't know if that could be the problem?).


Nice to hear from you again and soon NEWYEAR, I think Johnny Walker and the Crown Royals and MR. Jack D and the Bubbles may stop in for a few....  ;) :P
UPDATE 

Johnny is coming early like tonight as this PASTA BOWL CIRCUIT IS RIPPIN MY LAST NERVE :o
Deep breath now (and have a sit down with Johnny et al)  ;D


Just so you know I think we are reaching a point that loose connections and wires everywhere that is becoming almost impossible to get it stable. If I bump anything it can throw it into a state of search for long periods to find it.

I believe I am going to have to attempt and start hard wiring to stabilize the circuits.

What is your thoughts regarding this. as I am wasting tons of time chasing 1 loose connection.   :-\ :P
I think it would be a good idea to move the subcircuits to eg. Vero board, but keep each of the boards separate, to make it easier to trace down hick-ups.
They could all be strapped to a piece of wooden board or MDF.

It is probably a little to early to move things to a real PCB (except for the test generator perhaps).

How do you feel about making a PCB btw.?


Now my GF is shouting "dinner" from the kitchen, so I better leave the keyboard and go pig out on steaks and an evil chocolate cake with stratiatelli ice *yummy* ;D


;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
;D  Have a Happy New Year! ;D
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #182 on: January 01, 2010, 11:29:04 AM »
Happy New Year ;D Hope you had a good day!
Mr Soeren

Quote
OK, perhaps we should save this for when the stability of the rest of the circuit is restored.

Yes I think so too! :)


Quote
What do you mean? Doesn't it travel the full 180°?

It Depends on the setting of VR1 of the first circuit, by raising and lowering it changing output voltage between 4v - 7v holds the PW to a set width to the servo, actually the best I get is about 130 degrees.
Quote
The signal (input) to 2.3 should be within the range that C1 (TP11) covers, or one of them has to be modified (don't know if that could be the problem?).
I will look at this matter closer to see if a change needs to be made. :P
Quote
I think it would be a good idea to move the subcircuits to eg. Vero board, but keep each of the boards separate, to make it easier to trace down hick-ups. They could all be strapped to a piece of wooden board or MDF.
I think I am going to do this so some thing are hard wired I'm starting to feel a little like a DOG CHASING IT'S TAIL ;D :P :- ;)
Quote
How do you feel about making a PCB btw.?

I believe that the Generator circuit would be a great first attempt at a PCB. I have been looking for a old MONOCHROME LASER PRINTER. DO you think this type of proses is a good way to start by copy transfer to copper as my resist? :-\
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #183 on: January 01, 2010, 09:50:59 PM »
Hi Neil,

It Depends on the setting of VR1 of the first circuit, by raising and lowering it changing output voltage between 4v - 7v holds the PW to a set width to the servo, actually the best I get is about 130 degrees.

It just takes a little twiddling with the levels to get the full 180°, but it's better left to the finishing touch.


I think I am going to do this so some thing are hard wired I'm starting to feel a little like a DOG CHASING IT'S TAIL ;D :P :- ;)

Yes, I might have mentioned that I rarely use solderless boards myself. Either I just make a PCB, or if it's a circuit that may need twiddling or where I might change my mind while building, I use the Manhattan Mount method.


I believe that the Generator circuit would be a great first attempt at a PCB. I have been looking for a old MONOCHROME LASER PRINTER. DO you think this type of proses is a good way to start by copy transfer to copper as my resist? :-\

Personally, I use drafting paper as film and use photo-sensitized PCB, but that takes a (timed) UV light to transfer the image.
If you want to try the "iron on" method, you need to print on glossy (photo) ink-jet paper, iron it to a cleaned blank copper clad board and soak it for hours until the paper can be peeled off, while the toner stays on the copper - make sure to set the printer to dark or semi-dark to get a reasonably coverage (pinholes and broken wires are common with iron-on, but the traces are wide enough for this to be a minor problem - if at all).

Test Genny changed slightly for easier tuning while on PCB
The last page is the PCB mirrored if you need this (you don't with the two methods described though).
R3 and R4 are for making a series and/or parallel combination with R1 (if not used, either use a jumper or mount R1 askew to avoid the jumper).
R5 is used if the total range of the trimmer (or potentiometer) needs to be less than what you have.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #184 on: January 03, 2010, 09:50:29 AM »
Hi Soeren
A quick question.

I like the UV method with being able to expose right away once the mask is set to the photosensitive boards.

What Chemical do you use to finish with after you Mask the board and expose to the UV? ??? ;D

Here is a product thats local to my area and it is in stock to pick up. http://www.radioshack.com/product/index.jsp?productId=2102868 :P


UPDATE ON CIRCUIT

I am currently remounting the solderless boards to a larger area so keeping them separated and to make sure I can Isolate each Circuit a little, plus when it comes time to actually test with the V8 I think it will be a more stable platform to work with. ;)


« Last Edit: January 03, 2010, 10:05:55 AM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #185 on: January 03, 2010, 06:13:01 PM »
Hi Neil,

What Chemical do you use to finish with after you Mask the board and expose to the UV? ??? ;D

The easy way is to buy presensitized board.

Then you need to establish the exposure time.
This can be done by making a strip of PCB, covering most of it with eg. a metal plate and expose it for half a minute, moving the plate to expose a bit more of the PCB, expose for another half a minute and so on until you have 10 "steps", where the first bit will have seen 10 times 30 seconds (5 minutes), the next bit 9 times 30s (4.5 minute) and so on. Allways use the same concentration to develop the PCB and the same distance from the same UV source, for this to hold true each time.

Develope it and etch it. If you have made equal intervals, or have marked it in some way, you will then know the exposure time to use (the one with the shortest total exposure getting the copper completely etched away).

For an UV source, several options exists. A "facial solarium" (whatever they're called) at a distance of about 8" to 10" has worked fine for me (after I got such a beast and didn't know what else to use it for), a truckload of UV-LEDs, a mercury vapour lamp, or whatever you have with a high content of UV
Don't look into UV!!! and don't expose you skin too much to it (it's quite concentrated doses).


To develope the UV exposed PCB, you need sodium hydroxide (NaOH, caustic soda), about 3 to 7 grams into 1 liter of tap water
(should be up to around ½ to 1 ounce a gallon, if my conversion is correct - do check please).
This feels a bit greasy, but it ain't, it's your fingers being etched that gives that feeling - rubber gloves is a very nice thing!
Carefully running a (rubber gloved) finger over the area will help things along.

When the sensitized film is developed completely, it's time to rinse under lots of running water.

Then you etch the board. You can use ferric chloride like the one you linked to (it's a bit expensive though, try a drugstore, or whereever you buy chemical substances), but take a look at this link of several etchants.
Personally, I prefer ammonium persulfate, but it needs to be heated and agitated to work right. Most etchants need to be stirred more or less, but with ferric chloride, it's often enough to float the PCB copper side down -  a couple of handles made from tape in the shape of _/\_ on the other side will help float it.
Just don't get ferric chloride on your clothes or skin - the clothe will be ruined for good with brown stains and it may take a week to get it off your skin. All of etchants, if spilled, should be rinsed off with plenty of water, followed by a regular wash (immediately, or your clothes may have holes where the etchant was, after a wash or two).


I am currently remounting the solderless boards to a larger area so keeping them separated and to make sure I can Isolate each Circuit a little, plus when it comes time to actually test with the V8 I think it will be a more stable platform to work with. ;)

I would recommend mounting on Veroboard/stripboard, as this gives a more rigid construct - if you have a small Veroboard for each section, you can be sure the leads won't pop out (as they're soldered) and you can work on (and test) one block at a time, knowing how the other blocks work.

A solderless board near the vibes of a V8 sounds a bit challenging to me ;D
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #186 on: January 05, 2010, 08:47:19 AM »
HI Soeren

Thanks for the tips on making the PCB's I will gather the needed things to try my hand at this. ;D

I will be off line for a few days as this switch over to the vero boards will take a day or to to get set up.

I will come and SCREAM HELP as needed! ::)

We're getting pretty close to having a good test set up, it will be fun getting it hooked up to the V8 and having a go of it, and I will make a few videos so you can see your design come to working life..........

 Frankenstein--"ITS ALIVE____ITS ALIVE" as you scream in a very maddening voice...... :o ;D

I will be back in a little while with a few more hopefully stable circuit boards.
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #187 on: January 06, 2010, 12:07:41 PM »
Hi Neil,

We really need to get the jitter out of it, before you mount it on the V8, as otherwise the servo will run itself down faster, as the motor will be constantly running back and forth.

Just yell if the PCB making is acting up.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #188 on: January 06, 2010, 09:51:12 PM »
Hi Soeren
Quote
We really need to get the jitter out of it, before you mount it on the V8, as otherwise the servo will run itself down faster, as the motor will be constantly running back and forth.


I'll be back long before the V8 ever sees the circuit, I know it is not ready for a test run yet. But I do need to stabilize it as much of the circuitry as possible to achieve seeing where the real problems still hide. ;D

DO you think this type UV bulb would work for PCB exposer? I have one that my Son has. Just thought I would ask what you think about it. LINK BELOW

http://www.petmountain.com/product/reptile-fluorescent-bulbs/504054/zoo-med-reptisun-10.0-uvb-desert-bulb-26-watts.html

Zoo Med Reptisun 10.0 UVB Compact Fluorescents are here! Get the quality of Zoo Med’s ReptiSun linear fluorescents with a new threaded base that fits into any standard clamp-lamp, no separate ballast to buy! Helps prevent or reverse metabolic bone disease in captive reptiles.

For all Desert and Basking Reptiles
10% UVB Output
30% UVA Output
Dimensions: 6"Long x 2"Wide
26 Watts = 130Watt Standard Incandescent Bulb.

These energy efficient (26 watt) lamps are available in new 10.0 high UVB output. Provide the UVB your reptiles need with long lasting, cool burning ReptiSun 10.0 Compact Flourescent.

« Last Edit: January 06, 2010, 10:01:49 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #189 on: January 07, 2010, 02:17:07 PM »
Hi Neil,


DO you think this type UV bulb would work for PCB exposer?
I would think so, perhaps with a bit longer exposure time, but it's easy to test.
I would recommend a distance of around 1.5' to get close to equal distance from the lamp to each corner of the PCB material.
The lamp has got the highest amount of light sideways, so don't just hang it down from the ceiling (and down stare into it).

Hold down the printed drafting paper with a glass plate of max. 3 mm thickness (glass filters some of the UV, but i have made numerous PCBs with 2mm to 3mm glass. Printed side against the PCB.
A test strip need not be more than a narrow strip (1/4" should do).

When making the PCB, cut it a bit larger than needed and trim after etching (besides it's easier, it also removes etchant that might have been trapped in the outer edge.

A file or emery paper on the trimmed edges and corners makes the PCB more pleasant to handle.

First day at work today, so I have answered half a month worth of email (well, almost, I saved some for tomorrow ;-/)
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #190 on: January 17, 2010, 02:54:47 PM »
Hi Soeren

Hope this get to you.
Just wanted to update you I have finished 2 section on Vero board and they are working very well.

How nice that wires are not coming out and endless searching. ;D I will be starting on the 2.3v Monday and get it on a vero. I know we may have to change a few things but things are so much more stable I will just un and re solder :P

Hey hope all is well in DK and your home, and the work load is light. Take care my friend. :)
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #191 on: January 17, 2010, 04:00:30 PM »
Hi Neil,

Yes, I still read the board a little these days.

Glad to hear you have progress on the building and just in case the board falls apart, you can reach me on my email at Spambox(at)im26y(dot)com (which I sometimes don't read for days though, unless I expect some email besides the regular junkmail, as I get tonnes of email at work and so, often cannot stand continuing when I get home, but eventually I will get to it).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #192 on: January 25, 2010, 10:50:54 PM »
Hi Soeren
Just wanted to let you know I am fighting this last part of the circuit 2.3v. I am hooking something up wrong just haven't found it yet. >:(

Soon as I am able I will give you a shout and see if we can pin this bugger down :P

Here is a picture of the test gen and second section.

And as always thanks for sharing your knowledge. :P
Take care
Neil

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #193 on: January 29, 2010, 11:21:35 AM »
Hello Soeren
Well I must say I am reaching a point of madness :o, If I don't resolve this soon I will give in and ask for the 555timer circuit for the last part of the V8 gov?

I am having a terrible time getting this last section done, everytime I build it it up to check TP11 with TP13 to B+ and ground. There is a pulse on the trace before I even check TP11 and I cant find why it is happening I know it's not supposed to be there as we jumped this spot before.

Anyways I still intended to finish the circuit to the final 2.3 v no matter what, it is the principal of the thing :P
 But I also am reaching a point on the genset that I need to control the RPM's and if I don't finish the circuit I will have to apply the hated mechanical gov soon >:( "Which I have wanted to avoid from the very beginning!"

I know you have shared so much with me and I can't thank you enough as most shunned me when I first asked for help here and you were kind enough to ask a few simple questions to see if I could even follow your directions.

Once again I must thank you for your Time, Patients and Knowledge, I am always thankful for the chance to learn and a great instructor! ;D

Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #194 on: January 31, 2010, 01:23:05 PM »
Hi Neil,

[...] everytime I build it it up to check TP11 with TP13 to B+ and ground. There is a pulse on the trace before I even check TP11 and I cant find why it is happening I know it's not supposed to be there as we jumped this spot before.
If TP13 is at B+, then TP11 will be a bit below 3V.
While "Signal" is higher than the potential at TP11, TP12 will be high and nothing further will happen.


Anyways I still intended to finish the circuit to the final 2.3 v no matter what, it is the principal of the thing :P
 But I also am reaching a point on the genset that I need to control the RPM's and if I don't finish the circuit I will have to apply the hated mechanical gov soon >:( "Which I have wanted to avoid from the very beginning!"
Then we better shape up a bit and put our minds together - mine need to be warmed up to the circuit again, it's been sooo long since it was fresh in my mind  ;D

When is your approximate due date?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #195 on: February 01, 2010, 01:04:21 PM »
Hi Soeren

Just wanted you to see exactly where I am working as I try to achieve the rise signal on TP11. MY problem is I am getting continuous  a HIGH to LOW pulsing trace @ TP11 before I even check for the _/ rise signal :P

I am rebuilding as I type this note to you and will update if I fixed it tomorrow.



This is your QUOTE when I was having this issue before.

Quote
My explanation could have been better as well, so here goes:
As long as you touch the wire (TP13) to B+, TP11 is gonna be low, either less than a few hundred mV or around 3V if you have the zener diode in circuit (doesn't matter whether this or that at this moment).
As soon as you remove the wire, you should see TP11 rise like _/¨ (in a few ms, so don't blink) and stop somewhat below B+
When the voltage rise on TP11 reach the same potential as you have set "Signal" to, TP12 should go low.
It's the delay from your release TP11 to TP12 goes low that you should be able to vary with the pot.

How it works:
Lets say you have set "Signal" to 6V.
When the rising voltage on C1 (TP11) reach a shade over 6V, IC1B will go low, since it's non-inverting input is now lower than the inverting input.

It's this low going pulse that will be used for resetting the flip flop consisting of IC3A and IC3b, when we add the next block.

Hope that helps - I assume it's R8 that had you pulling hair - once again, I am sorry for that!

This is where I am trying to get the circuit to operate correctly. I am breaking it back down as you had me do before and take a step at a time to correct this issue . As I am sure it is my wiring that's give me a fit :P

I am about 2 weeks out before needing to set the V8 gov circuit to work :o

I think I am getting a little "Rube Goldber syndrome" between the circuit and my Gasifier;D
« Last Edit: February 01, 2010, 01:17:09 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #196 on: February 01, 2010, 04:02:36 PM »
Hi Neil,

Just wanted you to see exactly where I am working as I try to achieve the rise signal on TP11. MY problem is I am getting continuous  a HIGH to LOW pulsing trace @ TP11 before I even check for the _/ rise signal :P
Is IC3 in place or not when this takes place?
What's on "Signal"?


This is your QUOTE when I was having this issue before.
And you have R8 in circuit?


This is where I am trying to get the circuit to operate correctly. I am breaking it back down as you had me do before and take a step at a time to correct this issue . As I am sure it is my wiring that's give me a fit :P
OK, I need to know the conditions around it, to be able to make an informed guess, as the surrounding components, being there or not, will change the behaviour of the circuit.
What goes on the "Signal" input and what do you measure on TP11 etc.
Are your findings now consistent with your previous work?  (Perhaps reread the posts in question).


I am about 2 weeks out before needing to set the V8 gov circuit to work :o

I think I am getting a little "Rube Goldber syndrome" between the circuit and my Gasifier;D
You had it work before, so it should be quite possible to do - a visual inspection of the holes in the solderless board, in order to reveal any loose connections, might be a good idea.
Don't have wires (or component wires) from an output go extremely near any inputs on IC3 and if you have wires from outputs as well as inputs going parallel in close proximity, place them a bit apart.

(If all else fails, I could still make you a program for a µcontroller to replace most of the circuit).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #197 on: February 01, 2010, 11:08:14 PM »
Hello Soeren

Well I am starting to make some headway. and I hope to get IC3 on the vero board tomorrow and running smooth. Crossing my fingers ::)

QUESTION! As I was taking a closer look at what I thought was a LM334 I see now that what I am using is a LM234. That being said is it critical to have the lm334 or can the 234 handle the job? If they wont I will have to order as I only have 2 of the LM234 and no LM334's :-\ Also I found the exact R1 and R2 needed to hold the Thermal levels you spoke of!
I am going to try for 2 more days to finish the 2.3v and make it work on the Vero Boards. If all else fails I may have to ask for the code to run Ucontroller :'( But truly I would love to bring this circuit all the way to a finished board, as we have a lot of time invested here. And your design deserves it's day running that servo and V8 ;D
« Last Edit: February 01, 2010, 11:20:32 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #198 on: February 02, 2010, 04:20:27 PM »
Hi Neil,

Well I am starting to make some headway. and I hope to get IC3 on the vero board tomorrow and running smooth. Crossing my fingers ::)
It's tough building with crossed fingers  :P
I'm sure you'll get it working!


QUESTION! As I was taking a closer look at what I thought was a LM334 I see now that what I am using is a LM234. That being said is it critical to have the lm334 or can the 234 handle the job? If they wont I will have to order as I only have 2 of the LM234 and no LM334's :-\ Also I found the exact R1 and R2 needed to hold the Thermal levels you spoke of!
LM234 is the same chip, only with closer tolerances (i.e. a better more precise version), so no problem.


I am going to try for 2 more days to finish the 2.3v and make it work on the Vero Boards. If all else fails I may have to ask for the code to run Ucontroller :'( But truly I would love to bring this circuit all the way to a finished board, as we have a lot of time invested here. And your design deserves it's day running that servo and V8 ;D
I fully understand if you're fed up with the circuit and you mustn't think that you have a duty (or whatever) to go on!  Just tell me if that's the case - at least you've gotten some experience in using a 'scope and that will come in handy for other circuits as well.

All that said... You had it running, so I'm sure you can get it going in no time.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #199 on: February 02, 2010, 06:36:26 PM »
Hello Soeren

Quote
All that said... You had it running, so I'm sure you can get it going in no time.


You are correct it is running and on Vero boards ;)
 I will mount them on Hard surface after we fine tune to hold that 300 RPM range. I believe that was the number we want as far as throttle responce? :-\

Now we did have a problem with the jittery servo but as I explored I found that it is noise from the TEST GEN CIRCUIT if I applied my finger to R1 of the circuit, it stopped the jitters and also cleaned the signal trace that had shown a little glitch as the test signal started to go high on the scope.
So I don't think we have a big problem there. :-\

But I must ask? When I put my finger in touch with the Test Gen circuit R1 is it acting as a filter cap would work? ::)

Anyways, here is a little clip of it in action, I will wait for you to tell me what should be next. ;D

[youtube=425,350]http://www.youtube.com/watch?v=PQelkFNwE30[/youtube]
 
 
« Last Edit: February 02, 2010, 08:27:30 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #200 on: February 03, 2010, 05:43:47 PM »
Hi Neil,

You are correct it is running and on Vero boards ;)
Über ;D


I will mount them on Hard surface after we fine tune to hold that 300 RPM range. I believe that was the number we want as far as throttle responce? :-\
I believe it was 1,200RPM = 80Hz (for a 4 stroke 8-banger).


Now we did have a problem with the jittery servo but as I explored I found that it is noise from the TEST GEN CIRCUIT if I applied my finger to R1 of the circuit, it stopped the jitters and also cleaned the signal trace that had shown a little glitch as the test signal started to go high on the scope.
Had it been built on the PCB I made, it would probably not be a big issue, due to the copper pour.
You did use a CMOS version of the 555, right?
You might wanna put 10nF to 100nF from pin 5 to ground anyway, as it decouples the control voltage and hence stabilizes the reference used within the 555 to define the switching thresholds.
A 100nF cap from pin 8 to pin 1 (as close to the pins as possible) won't hurt either.
Does the jitter go away or increase, when you retract any interfering body parts at least 1' from the circuit?
 
What frequency range does it cover as it stands?
It should be a range centered around 80Hz.
Set the pot to midpoint. If the frequency is lower, increase C1 with the same amount as the deviation (roughly) and v.v.

If the center of the pot gives 70Hz with a cap of 22nF you could use:
22nF*70/80 = 19.25nF instead (by adding eg. 15n and 4n7 in parallel or 18n and 1n2).


But I must ask? When I put my finger in touch with the Test Gen circuit R1 is it acting as a filter cap would work? ::)
Not easy to see from that distance, but either it's because you're working as a cap to ground, or the added loading of the R1/C1 node - I bet it changes the frequency a bit as well.


I will wait for you to tell me what should be next. ;D
That would be to get the frequency to ~80Hz mid-band and stabilizing it will do no harm either.
And... Decide a (tentative) design goal for the upper and lower RPM tolerance where you want the servo to be at the ends of its travel.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #201 on: February 04, 2010, 02:16:46 PM »
Hi Soeren

Quote
I will mount them on Hard surface after we fine tune to hold that 300 RPM range. I believe that was the number we want as far as throttle responce?

I believe it was 1,200RPM = 80Hz (for a 4 stroke 8-banger).

The 300 RPM I mentioned in this quote was referring to the upper and lower limit of the servo swing 900 to 1500 RPM;D Hope that cleared up what I was trying to say ??? :)


Quote
What frequency range does it cover as it stands?

As it stands it swings from 17.5mS to 8.5mS I believe 57.1Hz to 117.6Hz. This is before doing any stabilising.

After adding the caps it now swings 8mS to 15mS  125Hz to 66.7Hz

Quote
You did use a CMOS version of the 555, right?
Well imagine you asking that question and after looking at the 555 it is a NE555 which I don't think is CMOS "I do have a LM555 that was right in the same container.

After I added the Caps to pin 5 to GRD and pins 8to1 it took all jitter out of the circuit :P
Do you think I should switch them the LM for the NE now that the circuit is stable?:-\

I am going to have a close look at the datasheets on these Timers now that you have taught me something "new" again as I didn't know there was a big difference :o :-[

Well Soeren I am feeling very good about this as the circuit appears to be stable and I have a very close 12.5 mS reading to mid range on VR1  I may have to bump it a couple more nf.   But it is very close now ;D



I'll check later to see if you get a chance to read this.
« Last Edit: February 04, 2010, 04:21:16 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #202 on: February 04, 2010, 06:01:07 PM »
Hi Neil,

The 300 RPM I mentioned in this quote was referring to the upper and lower limit of the servo swing 900 to 1500 RPM;D Hope that cleared up what I was trying to say ??? :)

Of course, my bad for not rereading 200+ posts every few days ;D
(Internet time is a strange phenomenon - a week away from a circuit and I need to review it all - my only excuse is that I'm juggling at least a handfull of projects at any time and they seldom gains from getting mixed up  :D)


As it stands it swings from 17.5mS to 8.5mS I believe 57.1Hz to 117.6Hz. This is before doing any stabilising.

After adding the caps it now swings 8mS to 15mS  125Hz to 66.7Hz

That equates to 1000 RPM to 1875 RPM
Making C1 20% larger should put 1200 RPM at around the middle of that - if C1 is 22n now, a 4n7 in parallel will be fairly close and will get you the +/- 300 RPM range (plus some, but it's OK for testing).


Quote
You did use a CMOS version of the 555, right?

Well imagine you asking that question and after looking at the 555 it is a NE555 which I don't think is CMOS "I do have a LM555 that was right in the same container.

After I added the Caps to pin 5 to GRD and pins 8to1 it took all jitter out of the circuit :P
Do you think I should switch them the LM for the NE now that the circuit is stable?:-\

Ahaa, I thought it smelled a bit that way from your last post, but I said to myself "No it cannot be, 'cause I explicitly wrote CMOS555 and Neil's too carefull to do such horrible stuff"  :P ;) ;D

Seriously...
The big difference is that the "good" old 555 (i.e. LM555, NE555, UA555 and whatever) generates transients on the power line when the output is shifting and it doesn't go to the rails either.
The CMOS versions (i.e. LM555C, ICL555, CMOS555 and several other names), although not as current capable, has got outputs that does go to the rails and it doesn't make horrible transients on the power line.
It's the shifting transients that has made the circuit curl a bit.

Depending on the type of circuit, transients may or may not matter and when you use the old 555, you decouple the control voltage pin (pin 5) by a cap - 100nF is usually slabbed on by poor "designers" as a cure all, but often something as low as 1nF or 10nF is more than adequate, at other times you need to go higher than 100nF - it all depends on the circuit, the impedance of the supply lines and how sensitive timing is.
Over time, you get a gut feeling for selecting the cap, but until then, just start low and increase until stability shows (if nothing else is wrong of course).


I am going to have a close look at the datasheets on these Timers now that you have taught me something "new" again as I didn't know there was a big difference :o :-[

The big difference is whether you use CMOS or not (easily seen from the price tag, as the CMOS versions are 3..5 times as expensive IIRC).
But... There's minor differences between several of them, My buddy Tony has got a page that you could go through when you need to kill some time, it's a very informative 555 Tutorial that will help you way more than studying datasheets to begin with.

And if you feel up to learning more, there's other tutorials (and bunches of circuits, including one I made) at the Electronics Page


Well Soeren I am feeling very good about this as the circuit appears to be stable and I have a very close 12.5 mS reading to mid range on VR1  I may have to bump it a couple more nf.   But it is very close now ;D

As long as you can dial in the needed range, there's no real need to change it any further. When this is done, you'll probably need to change it for your next experiments anyway.


I'll check later to see if you get a chance to read this.

Well, I did ;D

When you can dial in 900/1500 RPM, please tell me what output voltage you have on the "Signal" pin at 900, 1200 and 1500 RPM and what components in the first part that is different from the schematic.

I'll start gathering it all into one file then and you can note any further changes you made (might take a few iterations to cover for missing light and greasy glasses ;)), so that we can get the schematics up to date and get a real PCB layout ready for it.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #203 on: February 04, 2010, 11:19:19 PM »
Hi Soeren
OH yes it is Über at least for me! I am very happy to reach this point ;D :P
And nearing the point of making my first PCB's  8)

Now I hope I used the word " Über " in it's correct context as being a Great or a Superior moment? :P

OKay here are the results.
Using a DMM it made the servo move very slightly as I checked the voltage and repeated it for each measurement.
 I was slightly confused when asking for the voltages at the signal so I went back and measured from the signal IN on ver2.3 and signal OUT of ver 2.3 they are below in a picture.

I hope that this is the correct readings that you need?

Quote
As I sweep VR1 fully on the Test Gen Circuit the Servo is giving me ~80'degree movement back and forth.
Quote
Now that the curl is gone on the signal and jitters have stopped the 7805 VR has cooled down and I am not sure it even needs a heat sink :-\

Below are the revisions made to first part of circuit "Revisions to V8SG_4.0 PDF"
« Last Edit: February 06, 2010, 01:37:22 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #204 on: February 06, 2010, 07:04:51 PM »
Hi Neil,

Now I hope I used the word " Über " in it's correct context as being a Great or a Superior moment? :P
You've got it!


I hope that this is the correct readings that you need?
Precisely what I asked for :)


Quote
As I sweep VR1 fully on the Test Gen Circuit the Servo is giving me ~80'degree movement back and forth.
That's what we're gonna fix now.


Quote
Now that the curl is gone on the signal and jitters have stopped the 7805 VR has cooled down and I am not sure it even needs a heat sink :-\
At least it doesn't do any damage.


Below are the revisions made to first part of circuit "Revisions to V8SG_4.0 PDF"
I jotted them down for a brain grind before you edited the post, but I was so sleepy that I kept falling asleep, wake up and trying to gather enough momentum to get to bed, falling asleep before that happened (etc. about 5 times until it was around 9 a.m. - too bad I slept with half a glass of Coke in my hand - it sure spreads little drops like a frag when you drop it  :().

It is the first numbers you wrote (from Signal in SV1 of the schematic that's got the servo in the other end - lets call it Schematic 2 and the other, who connects with the Hall is then Schematic 1).


I would like you to make a some more measurements here:
If you take the same readings with VR1 (in Schematic 1) turned fully CW and CCW, or as far in each direction that will still give a response within ~1V to ~9V (still for 900, 1200 and 1500 RPM), perhaps a more balanced voltage deviation can be found out (I'll do some math on the readings) and maybe the response of the rest of the circuit can be made more... Well, responsive.

And what about the changed component values in Schematic 2 so far?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #205 on: February 06, 2010, 11:11:43 PM »
Hello Soeren
Quote
too bad I slept with half a glass of Coke in my hand - it sure spreads little drops like a frag when you drop it.
Hope it was on tile and not carpet, makes it a tad bit easier to clean up :P

You are in the medical Field and I thought that REST was one of the orders from the DR. ???

The way it sound your job keeps you at full speed most of the time :( I hope you have a vacation soon ;)

Quote
as far in each direction that will still give a response within ~1V to ~9V

Well the readings are in and this is the result. First off the voltage level did drop below 1v down to .06v so I dialed VR1 on schematic 1 to start at ~1v.

Also are my Time/div correct?---(900=16.7mS) (1200=12.5mS) (1500=10mS)

The reason I ask is it would seem that the TIME would be linear but it didn't come out that way. But the voltage reading were about a 1/2 volt each as the RPM was changed and almost 1 full volt each as VR1 was fully turned the other way.

Also I wanted to make sure you were aware that I made a big mistake when I put the final resistor R8 in Schematic 1, I put a 47k ohm instead of the 470k what a blunder on my part :-[

CW@900=1.02v
CW@1200=1.54v
CW@1500=1.98v

CCW@900=3.90v
CW@1200=5.15v
CW@1500=6.32

As Far as changes to schematic 2 they are below in a jpg.
« Last Edit: February 06, 2010, 11:31:52 PM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #206 on: February 07, 2010, 05:39:59 PM »
Hi Neil,

Hope it was on tile and not carpet, makes it a tad bit easier to clean up :P

Wooden planks - at least the glass didn't shatter  :)


You are in the medical Field and I thought that REST was one of the orders from the DR. ???

The way it sound your job keeps you at full speed most of the time :( I hope you have a vacation soon ;)

Rest is only for patients, staff is supposed to run full speed plus  ::)


Well the readings are in and this is the result. First off the voltage level did drop below 1v down to .06v so I dialed VR1 on schematic 1 to start at ~1v.

Also are my Time/div correct?---(900=16.7mS) (1200=12.5mS) (1500=10mS)

Yes.
For a four stroker, number of ignitions are 1 every second revolution times number of cylinders: (RPM/60)*(8/2) = RPM/15 [Hz]
To get the time for each period, take the reciprocal value of the frequency: 15/RPM


The reason I ask is it would seem that the TIME would be linear but it didn't come out that way. But the voltage reading were about a 1/2 volt each as the RPM was changed and almost 1 full volt each as VR1 was fully turned the other way.

Not quite sure what you mean, but the voltage at "Signal" is not entirely linear it seems, but read on.


Also I wanted to make sure you were aware that I made a big mistake when I put the final resistor R8 in Schematic 1, I put a 47k ohm instead of the 470k what a blunder on my part :-[

What you're saying is, that R8 is 470k in your working circuit, or?


CW@900=1.02v
CW@1200=1.54v
CW@1500=1.98v
[...]

Thanks, lets stick to the original values.


As Far as changes to schematic 2 they are below in a jpg.

The LM334, I'm not gonna change, as the 334 would do fine and the one you used is just a version with tighter tolerances. As I don't know what heatsink you used (and probably haven't got a CAD symbol for it, I didn't add it to the schematic.

Apart from that, I have now merged both the schematics into this one.
Please review all component values and tell me what needs to be changed.

What is now C7 and D3 (formerly C1 and D4) is changed to new values. use them and adjust VR1 to get a 170° to 180° response. Then, tell me how it went.

Later, when installing it, it doesn't matter if 1200 RPM is a *little* off the middle position, just check with a rev. counter that it settles at 1200 RPM and adjust the physical position of the servo/connection trim if not.
When we reach that point, you need to find out the physical travel of the gas linkage at +/- 300 RPM, to find out how far from the center of the servo horn the link should be mounted.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #207 on: February 09, 2010, 01:27:21 AM »
Hello Mr Soeren
Quote
What you're saying is, that R8 is 470k in your working circuit

Correct!

Well here is what happend after the changes ::) ::)

I made the changes that you requested, then powered the circuit and had no responce when sweeping VR1 on ether the Gen test circuit or Schematic 1.  So the only way I could fix this issue was to remove R5 100k that was in series with Vr1 on schematic 1. I hope that this action was okay?

 In the original schematic 1 the value of VR1 and R5 together were a total of ~100k with VR1 max. :-\ If this action was okay I will pick up a couple 50k VR's  and put another 50k in series to correct only having a 100k VR1 in the circuit now.

After removing R5 I was able to adjust Vr1 on schematic 1 to allow the Gen Test Vr1 sweep the servo ~0-135 degrees but that was the limit.

I am attaching a video so you can see the other issue I'm having. When the Servo is moving from 0-100degrees it moves at full speed, but the last 35degrees it slows down and takes about 2 seconds to settle at 135. I wasn't sure of the cause so I just stopped.

So take a look at the video hope you can see what I am talking about.  

[youtube=640,505]http://www.youtube.com/watch?v=Zr-U-JZU_n0[/youtube]

« Last Edit: February 09, 2010, 01:54:20 AM by wheelyneil »
Take care
Neil

Offline Soeren

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #208 on: February 09, 2010, 12:17:34 PM »
Hi Neil,

Well here is what happend after the changes ::) ::)

I made the changes that you requested, then powered the circuit and had no responce when sweeping VR1 on ether the Gen test circuit or Schematic 1.  So the only way I could fix this issue was to remove R5 100k that was in series with Vr1 on schematic 1. I hope that this action was okay?

 In the original schematic 1 the value of VR1 and R5 together were a total of ~100k with VR1 max. :-\ If this action was okay I will pick up a couple 50k VR's  and put another 50k in series to correct only having a 100k VR1 in the circuit now.
It's quite OK.
The reason for a regular resistor in series with a variable is twofold. First, it keep one from turning the pot to close to 0 Ohm (overloading the output of the gate) and second, it allows a smaller trimmer, which then gives a better resolution.

If you can adjust it well enough with the 100k trimmer, it's quite OK to keep it. Else, measure (needs removal from the circuit) or eyeball the resistance, and put a resistor of lower value plus a trimmer about twice the difference.
Eg. if the trimmer is around 1/3 (i.e. 33k). Replacing it with a resistor of 22k in series with a trimmer of 22k (mid position will then be around 33k). a 27k resistor could be used with a 10k trimmer for even finer control.


After removing R5 I was able to adjust Vr1 on schematic 1 to allow the Gen Test Vr1 sweep the servo ~0-135 degrees but that was the limit.

I am attaching a video so you can see the other issue I'm having. When the Servo is moving from 0-100degrees it moves at full speed, but the last 35degrees it slows down and takes about 2 seconds to settle at 135. I wasn't sure of the cause so I just stopped.
It looks strange. You seem to turn it in intervals, what happens if you go from min to max in a single short turn.
How does the output look on the 'scope while that happens?
What are the min./max. timing limits of the servo pulse?

Btw. The test generator would probably be easier to use with a regular potentiometer and you could make a dial for it (eg. on an angled scrap of aluminum).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline wheelyneilTopic starter

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Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #209 on: February 09, 2010, 02:35:59 PM »
Hello Mr Soeren

Quote
It looks strange. You seem to turn it in intervals, what happens if you go from min to max in a single short turn.
Actually if you watch close the last VR1 turn in the video and look at the servo and VR1 turn closely I am at full turn, way before the servo's movement ends if 2 seconds is way before ::). Actually I can count it's time here as being around 2 seconds until it stops.

Quote
How does the output look on the 'scope while that happens?
Actually the servo pulse high time swings from ~1.7mS - 2.2mS. You can see the Servo High Pulse slow as it is reaching it's minimum high time.

It almost gives me the impression that a CAP is discharging down slowly through a resistor making the action described in the last 2 seconds :-\ I hope you can understand what I am describing?

Would reducing the value of C6or R9 change servo's pulse to bottom out faster? "Just trying to learn"

I will add the regular resistor and small trimmer before testing on the engine :P

Actually I think we are very close  to a great working proto type.

 In MHO the current servo angle sweep would be enough to control 900 - 1500 RPM. I just wasn't sure how to clear that slow movement right  at the  end of the servo's movement and seeing you are the master mind behind this project, I thought I should share this last little glitch :P
Take care
Neil

 


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