go_away

Author Topic: Question! and Help I need to build a v8 engine servo motor governor  (Read 26869 times)

0 Members and 1 Guest are viewing this topic.

Offline wheelyneilTopic starter

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #150 on: December 09, 2009, 05:25:36 PM »
Hi Daanii

 
Quote
You're close with this hardware solution. Don't give up now!

I wont till Soren gets fed up with me and say hit the road Neil :o

I really want this to work too! ;)
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #151 on: December 10, 2009, 09:13:06 AM »
Hi Neil,

Quote
That is correctly wired, but you need to use your 'scope on TP11 and TP12 and then touch the wire on TP13 to B+ to get the pulses. Vary the pot and touch TP13 to B+ again for a new pulse.
You are looking for varying delays between the pulses on the two traces.

Well I am at a dead stop! I have checked the wiring and switched out lm393's and still no readings that should be there.
My fault entirely!
Sorry about that, but I forgot to note down R8 as one of the resistors to include (from TP12 to B+).
It has to be there, since the comparator, LM393, has got an open collector output, so it only pulls towards ground and need the pull up to show anything but low.
Very sorry  :-[

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 you 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!
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #152 on: December 10, 2009, 01:38:05 PM »
Hi Soren

Quote
My fault entirely!
Sorry about that, but I forgot to note down R8 as one of the resistors to include (from TP12 to B+).
It has to be there, since the comparator, LM393, has got an open collector output, so it only pulls towards ground and need the pull up to show anything but low.
Very sorry  :-[

Soren, no need for sorry, if not for you non of this would be possible. ("Thank you") For bearing with my lack of knowledge. ;)

Also maybe I should pull a data sheet now and then and learn too.......... :o ::)

Picture below is maybe what I should have looked for... ??? ::)

And on top of that it's nice to have the smartest guy in the room stub his toe! :D ;D

Moving on now! ;)



The pulse on TP11 is just like you said when it goes high its perfect.

When TP13  is released from GRD. TP12 goes low any where from 2ms to 5ms after signal from TP11 starts rising, while changing VRx1 from 4v to 8v.  ;D

Also Thank you for a little more explaining what is happening, as it lets me look back and see how things are acting in the circuit. :D ;D

Tell me whats next. :P

« Last Edit: December 10, 2009, 02:25:01 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #153 on: December 10, 2009, 05:53:36 PM »
Hi Neil,

Tell me whats next. :P
The exact timing, we can trim later (it has to be adapted to the range of the real signal anyhow).

Next step is IC3 and surrounding components, up to (and including) TP15, but keep out R10 an onwards for now.

Sleep time here, but I guess you still have some hours to spare ;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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #154 on: December 10, 2009, 10:43:37 PM »
Goodday Soren

Quote
Next step is IC3 and surrounding components, up to (and including) TP15, but keep out R10 an onwards for now
.

It is done!  I'm not sure if I am testing the right way? ::)

Here is what I am doing.
Dual trace of TP12 and TP15 and still Using TP13 to B+ to make TP12 go low.
And when I do this TP15 goes high at the same time.

There is no lag time that I can see, both trace rise and fall at equal speeds.

Hope I did it right ?;D

If not I'm sure you will give me a good slap :o


I know at some point a real signal has to be added, but just did this to see how the circuit was reacting!

 
« Last Edit: December 11, 2009, 04:20:21 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #155 on: December 12, 2009, 05:20:15 AM »
Hi Neil,

Dual trace of TP12 and TP15 and still Using TP13 to B+ to make TP12 go low.
And when I do this TP15 goes high at the same time.

There is no lag time that I can see, both trace rise and fall at equal speeds.

I know at some point a real signal has to be added, but just did this to see how the circuit was reacting!

Here's an updated schematic.
There was a logical error, which your description, of TP15 going low when TP12 is (as it should go low when Reset), revealed to me.
On p2, there's  a drawing of the FlipFlop and the MonoFlop in their basic forms for explanation.

When this is done, it should be running by itself, and giving servo pulses (although at 12V!) of varying widths when you change the pot (VRx1) not drawn here.
When you have this result, we can go on to make trim the pulse width.

Btw. R9 is an odd value. Either use the nearest standard value (510k) for now, make it out of two resistors (510k+12k or use a trimmer of 22k with the 510k), but the exact timing is not that important now. p2 gives the formula, I have calculated for 17ms (for a total period of 18 to 19 ms).
The formula is in p2 as well.
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #156 on: December 12, 2009, 04:07:25 PM »
Hi Soren

Just wanted to tell you I will be gone till Monday night. GF is dragging me away for a couple days :P

I rewired the updated version but no pulses. I will try again Monday.

Also as I read your last comment about my description of what was happening with TP12 and TP15 it may have been stated wrong on my part.
Quote
There was a logical error, which your description, of TP15 going low when TP12 is (as it should go low when Reset), revealed to me

Quote
Dual trace of TP12 and TP15 and still Using TP13 to B+ to make TP12 go low.
And when I do this TP15 goes high at the same time.

I was trying to say TP15 went high, when TP12 went low.  To me it sounded as if you were thinking I said they both went low when TP12 went low?

 But I have already changed the circuit and I will have to go back and check it to makes sure.

I will recheck myself Monday. Sorry for the confusion and  delay :-[

Thanks for your help always
« Last Edit: December 12, 2009, 06:08:48 PM by wheelyneil »
Take care
Neil

Offline wheelyneilTopic starter

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #157 on: December 14, 2009, 01:33:46 PM »
Hello Soren

These quotes are from 3 post back.!!!!!!

Quote
Next step is IC3 and surrounding components, up to (and including) TP15, but keep out R10 an onwards for now
.

It is done!  I'm not sure if I am testing the right way?

Quote
Here is what I am doing.
Dual trace of TP12 and TP15 and still Using TP13 to B+ to make TP12 go low.
And when I do this TP15 goes high at the same time.

There is no lag time that I can see, both trace rise and fall at equal speeds.

Okay Soren this is where I want to make sure you are not confused by what I am saying. So I know for sure to change the circuit to the new Updated ver 2.2

When I Bring TP13 to B+, TP12 is on a High Signal
When I remove TP13 from B+ TP12 goes to a LOW signal


NOW HERE IS WHAT I WANT TO MAKE SURE IS CLEAR

TP15 is going just the opposite of TP12

IF one of the Traces is HIGH the other is LOW

I am sorry to go over this again but when I read your post about a logic error and changed the circuit.  I reread your stament again and it seemed that you may have not understood what I was saying . The way I stated it!

So after you read this post please Tell me to continue with VER-2.0 or move along and update to Ver2.2

So very sorry for the mix up :'(
« Last Edit: December 14, 2009, 03:15:57 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #158 on: December 14, 2009, 04:28:10 PM »
Hi Neil,

So after you read this post please Tell me to continue with VER-2.0 or move along and update to Ver2.2

Actually, I've made one more (small) change to ensure levels, please build after this
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #159 on: December 14, 2009, 11:10:04 PM »
Hi Soren

Well I assembled the circuit up to TP16 and leaving out the  IC4 section and its components I started to test.

I hooked up a trace and it was running, @ TP15 12v/1.5ms high and 0v-17ms low, Also I had no change in pulse width by varying VRx1.

Then I started to Take Dual Trace on Q and /Q  it just stopped before I hooked up the 2nd channel.

Quote
And Cussing was herd far and wide >:(  Well at least in my head :P


Anyways its late time for sleep will try to find problem in the morning. It pretty much looks like a birds nest on the board. :o

Just wanted to let you know I was getting a pulse from it. Goodnight! And Goodmorning to you!
« Last Edit: December 15, 2009, 12:51:12 AM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #160 on: December 15, 2009, 03:59:39 PM »
Hi Neil,

Sounds strange.
Perhaps you should go over it with good light and a magnifying glass, it's very easy to misconnect something when making prototypes.

Please take a fresh look at it and then tell me if your results are the same then.
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #161 on: December 15, 2009, 09:37:03 PM »
HI Soren

Hope you can make some sense of this?

As at this point I am lost, SO what's New  
 There is no inverting or time offset. and signal is strange @ SET and no signal @ RESET

Here is a picture of the set/reset .

I went back and checked the TP12 and it responded HIGH and low as TP13 was @ B+ and GND.  Also I checked TP11 and it was making it 2ms rise signal /also when TP13 is @ B+ and removed from B+.

I hope you can see something I don't see or understand. To help us here.

So I will let you tell me what you want me to check a little at a time to find the bugs. :P

We are getting close to the end but it's getting harder

 I wish I understood Transistors better, as I think that is where I lose the action of the circuit.
 I know that they are acting as switches as the gate voltage or current changes .

So let me ask and no laughing :P

Here we go, Pin 10 of the mono-flop is going HIGH- LOW thats switching Q2 HIGH- LOW onto the base of
Q1. Q1 sends a high low pulse to IC1B pin6. IC1B has a ref voltage at pin5 that can fluctuate and when pin 6 of the IC1b starts going high. When it reaches a voltage level just above pin 5 of IC1b PIN 7 it  in turn makes the signal High at TP12 to the pin 6 IC3B of the Flip-Flop? ??? :-\ :o

I just wanted you to hear where some of my confusion  when trying to trace why the circuit is acting strange.

I will make the next post so you can see a few other TEST POINTS maybe it will help ???

I am very sorry if  I'm mucking things up. I don't mean too    
« Last Edit: December 16, 2009, 01:16:05 PM by wheelyneil »
Take care
Neil

Offline wheelyneilTopic starter

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #162 on: December 15, 2009, 09:42:01 PM »
Hi Soren
Here are some more TP's
Make sure to read previous post ;D
« Last Edit: December 16, 2009, 03:02:31 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #163 on: December 16, 2009, 03:50:57 PM »
Hi Neil,

As at this point I am lost, SO what's New  
 There is no inverting or time offset. and signal is strange @ SET and no signal @ RESET
The signal seems fine at set (it's the cap differentiating the clean square wave) as far as I can see - a picture with a shorter timebase (showing the pulse wider) will help deciding.
There must be a signal at reset or you wouldn't get any shift at the TP15 (TP16 is not very revealing as it will allways be the same as TP15 just cut down to the voltage of the zener).

If you had only Flip and no Flop (sort of speaking), it would stay in the Flipped position ;)


I went back and checked the TP12 and it responded HIGH and low as TP13 was @ B+ and GND.  Also I checked TP11 and it was making it 2ms rise signal /also when TP13 is @ B+ and removed from B+.
When you touch a wire to a point and release it from the same point, you actually make a train of pulses (try 'scoping the wire while you do it. Even with a push button you'll get contact bounce. It sounds like it's this that makes the pulse on contact/end contact.


I wish I understood Transistors better, as I think that is where I lose the action of the circuit.
 I know that they are acting as switches as the gate voltage or current changes .
Yes, they're used as switches here, which is the simplest way of using transistors.
When the base of an NPN (Q1) goes higher than around 0.65V above the emitter, the collector-emitter stretch "opens".
When the base of a PNP (Q2) goes lower than ~0.65V below the emitter, the emitter-collector stretch opens.


So let me ask and no laughing :P

Here we go, Pin 10 of the mono-flop is going HIGH- LOW thats switching Q2 HIGH- LOW onto the base of
Q1. Q1 sends a high low pulse to IC1B pin6. IC1B has a ref voltage at pin5 that can fluctuate and when pin 6 of the IC1b starts going high. When it reaches a voltage level just above pin 5 of IC1b PIN 7 it  in turn makes the signal High at TP12 to the pin 6 IC3B of the Flip-Flop? ??? :-\ :o

I just wanted you to hear where some of my confusion  when trying to trace why the circuit is acting strange.
Pin 10 of the MF is low for about 17ms (with the values mentioned) and since it's pulling the base of Q2 low, Q2 opens and makes TP13 and hence the base of Q1 high. This makes Q1 drain C1 down to around 3V (due to the zener).
C1 is kept discharged to these ~3V for the 17ms.
Then the MF times out, the FF is set, Q2 closes, Q1 closes and C1 starts charging with a linear ramp, due to constant current generator IC2.
When C1 reaches the voltage at "Signal", the comparator IC1B goes low, resetting the FF, which triggers the MF and the whole thing repeats.

To see some of the pulses, you need to adjust the trigger to "Negative trigger" and adjust until it gives a steady trig on a low going pulse. Then you can change the time base to show the pulse in more detail. (For a positive going pulse, the trigger needs to be set to "positive trigger" of course).

Varying the "Signal" input from 4V to 8V will give different width of the output pulse, since when 4V, C1 only need to charge 1V up, while if at 8V, C1 needs to charge 5V up and since it's charged by a CCG, it will take 5 times as long, so the pulse should be 5 times as wide.
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #164 on: December 17, 2009, 08:39:31 PM »
Hi Soren

Quote
If you had only Flip and no Flop (sort of speaking), it would stay in the Flipped position ;)

I think that statement is true. ;)

 But!!!!!!! ;D the circuit is so sensitive that anything applied to RESET pin 6 will trigger it and it will stay running. :o

Tp12 does not have to be connected to the RESET for it to run. If I touch and leave a open wire to pin 6 of the IC3B it runs while it is connected. It is like the smallest bit of capacitance or inductance I don't know if it is either,triggers it and keeps it setting and resetting.

And if I put a trace on TP12 while connected to /R I have to set the volts /div to 5milli volts to even see a pulse on the trace.

Now in the picture below you see a pulse high for ~2ms @TP16 with only a open wire @ /R, then if I apply TP12 that pulse shortens to ~ 1ms. But if I vary VRx1 it has no effect at all on the pulse width.

I hope I am making this clear enough. There is something wrong here I just don't know how to say it, correctly.

I am very sorry!
« Last Edit: December 17, 2009, 09:54:57 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #165 on: December 18, 2009, 11:04:25 AM »
Hi Neil,

But!!!!!!! ;D the circuit is so sensitive that anything applied to RESET pin 6 will trigger it and it will stay running. :o

Tp12 does not have to be connected to the RESET for it to run. If I touch and leave a open wire to pin 6 of the IC3B it runs while it is connected. It is like the smallest bit of capacitance or inductance I don't know if it is either,triggers it and keeps it setting and resetting.
Yes, it's a feature with any input that has so high an impedance like the CMOS4k series.
You never ever let them be unterminated (or let them get wet or feed them after midnight ;D)!


I hope I am making this clear enough. There is something wrong here I just don't know how to say it, correctly.

I am very sorry!
Don't be, just reapply R8, which clearly isn't keeping the input in check.
(And let's hope it didn't kick the bucket - high impedance circuits are very ESD prone if not handled correctly - some MOSFETs are very sensitive in that way, CMOS4k has got input protection diodes at least).
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #166 on: December 18, 2009, 12:10:09 PM »
Hi Soren

Problem fixed found a new circuit builder. ::)

« Last Edit: December 19, 2009, 03:20:23 PM by wheelyneil »
Take care
Neil

Offline wheelyneilTopic starter

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #167 on: December 19, 2009, 11:04:53 AM »
Hi Soeren

Well after a couple hours of checking and re looking at a couple data sheets I have found the cause of the pulse width problem!

You wont believe what it was :o


It was the the circuit builder :o :o :o :P :P :'( :'( :'( :-X

I am so sorry if I made you waste time trying to figure this out.  I went back and looked at the PNP data and I had it wired wrong. >:(

So now we have a pulse width that varies from ~1ms high to 3.5ms high and full sweep is 19ms  ;D

Once again I ask please forgive the screw up. It's birds nest soup here and it only takes one wrong connection. I am learning allot at your expense.


Now we can move along if that is okay? I will finish the 7805 supply and update you.
« Last Edit: December 19, 2009, 11:08:14 PM by wheelyneil »
Take care
Neil

Offline wheelyneilTopic starter

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #168 on: December 19, 2009, 04:00:20 PM »
Hello Soeren

A big day for me ;D

I hooked up the Servo :o

It was working as I adjusted VRx1 making the Servo arm move back and forth. How happy was I ?:P PRICELESS ;D

Okay now that my little moment of joy over took me I have to pull myself back together now and move along ;)

Just so you know. I am using a Computer power supply and the servo is steady as a rock and moves smoothly.  But the 7805 VR is getting smoking hot fast cant leave on more than 30 seconds. HEAT SINK?

Then I hooked up a older heathkit 0-15 volt supply and it began to have a very short jerky action continuously, it does respond to pulse change but shaky while doing it.

The reason I mention this is how filtered is a B+ supply from a car battery
                

 Just so you know, I am 51y/o and I must say I felt like a little kid at Christmas when that Servo Started to respond. :D



[youtube=640,505]http://www.youtube.com/watch?v=QYm8qFIvn9w[/youtube]
« Last Edit: December 21, 2009, 06:44:08 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #169 on: December 20, 2009, 05:57:16 AM »
Hi Neil,

I have been a little busy the last two days, shopping for X-mas presents etc. so have only had a few moments here and there to look it over. I opened this page a couple of days ago and have been looking at it every now and then, while examining the schematic, datasheets and other stuff relevant, trying to figure where the problem was.
Now I was gonna ask you to make a few measurements and component swaps, as I thought that maybe the set pulse in the photo 100_0634 might be so wide it made the reset go haywire.
When I click'd on "Quote", I got the "session time out error", so refreshed the page and the post I was trying to answer was changed, so I wondered whether the browser was playing tricks on me ;D
Luckily it wasn't

It was working as I adjusted VRx1 making the Servo arm move back and forth. How happy was I ?:P PRICELESS ;D
YES!
Victory is allways sweeter after a hard battle  ;D


Just so you know. I am using a Computer power supply and the servo is steady as a rock and moves smoothly.  But the 7805 VR is getting smoking hot fast cant leave on more than 30 seconds. HEAT SINK?
I don't know how much current your servo draws (unfortunately, the guy who made the Servo Data Base didn't include that rather important spec.), so this is slightly theoretical, but let's say the entire circuit takes 500mA and you use 12V for supply.
Then: (12V-5.6V) * 0.5A = 3.2W is dissipated in the regulator (if it draws 1A, it's 6.4W of course).
(With around 13.8V supply, the dissipation will be 4.1W for 500mA).
So yes, you need a heat sink!
If you don't have one available (lots to find in old cathode ray [non flatscreen] TV sets, old broken PC-supplies etc.), you could use a piece of aluminum or copper bar/plate as a temporary sink.


Then I hooked up a older heathkit 0-15 volt supply and it began to have a very short jerky action continuously, it does respond to pulse change but shaky while doing it.

The reason I mention this is how filtered is a B+ supply from a car battery
Did you 'scope the supply voltage (B+) when you used this supply?
Either it cannot put out the current needed (if it has got a relatively high output impedance), or perhaps its regulation goes crazy when the current surges start.
A big fat capacitor (eg. 4,700µF/40V) over B+ should help, but it would be more for the experience, as you won't have that problem when running from a lead-acid battery (which is very low impedance).

A car battery in itself is the most regulated source I can think of, so any issues in that department would be noise from the generator or ignition. Should there be any problems when you run it from the battery, a simple LC-filter can be used and if there's radiated noise, a metal box connected to the motor block would take care of that.


Just so you know, I am 51y/o and I must say I felt like a little kid at Christmas when that Servo Started to respond. :D
Hey, I'm born in March '58 and seeing your message and watching the video made me go *YESSS!* as well.
Watching the video, I fully realize the challenge you have seen - That is a serious bowl of spaghetti you cooked up ;D
Let's get the regulator in check and then put the parts together.

Please post what you used for C6, C7 and any substitutions you made along the way (If you remember them), so the schematic can be updated.
It's been 3 months plus, but perhaps it could be ready (at least on the bread board) before Christmas.
When it's all done, I'll lay out a PCB 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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #170 on: December 20, 2009, 08:25:13 AM »
Hello Soeren

Well here are the final changes to the circuits.

RED INDICATES CHANGE!

I thought pictures  would be easier. And I will add a Heat Sink to the 7805 ;)

Thanks again!
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #171 on: December 20, 2009, 10:46:56 AM »
Hi Neil,

R1 that you changed to 1k5, you really should replace with the stated value (1k2), as this is calculated for minimum temperature drift.

Don't forget that we still have to get the timing values tuned correctly (not a big deal, but it has to be done).
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #172 on: December 20, 2009, 12:57:50 PM »
Merry Christmas Soeren


Quote
R1 that you changed to 1k5, you really should replace with the stated value (1k2), as this is calculated for minimum temperature drift.
I don't happen to have a 1.2k resistor, local or from my parts store as a tried to get them. If I add a 1k+220ohm in series will that be close enough to hold the temp drift?

Quote
Don't forget that we still have to get the timing values tuned correctly (not a big deal, but it has to be done).
I will be waiting for your instructions.

Just a little information, in the video you see the Proto board. All 3 circuits are there, Signal Gen, Freq to voltage circuit and final Servo control section.
And I did try tying it all together and it did work as I increased and decreased frequency the Servo responded ~pretty much as it should. :o There was a couple issues but like you said there are other things to be finished. Before we discuss this stuff. :P

Well I am off to shopping also, my G/F is taking me to a tool store for me to pick my goodies ;D I like it that way I get just what I want from Santa ;)

Then off to her house and I will be kept captive for the evening. :P ;)

SO have a good night and I will look in on the posts tomorrow.
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #173 on: December 21, 2009, 01:29:27 PM »
Hi Neil,

I don't happen to have a 1.2k resistor, local or from my parts store as a tried to get them. If I add a 1k+220ohm in series will that be close enough to hold the temp drift?
Yes, that will be 1.7% off and if you use 5% tolerance resistors, it is well within spec.
Another way to arrive at 1k2 is to add two 12k resistors in parallel with the 1k5 for a spot on 1k2.
Whatever way, in the final circuit, they should be mounted as close to the chip as possible.


in the video you see the Proto board. All 3 circuits are there, Signal Gen, Freq to voltage circuit and final Servo control section.
And I did try tying it all together and it did work as I increased and decreased frequency the Servo responded ~pretty much as it should. :o There was a couple issues but like you said there are other things to be finished. Before we discuss this stuff. :P
That depends on what these issues are, so please do tell.
I reckon that a suitable range would be around +/- 300 RPM, so that if the motor runs at 900RPM, the servo is at one extreme and at 1500RPM the servo is at the other extreme (It would never get anywhere near those extremes though).
That equates to 60Hz and 100Hz respectively (so will require minor changes to the test generator).


Well I am off to shopping also, my G/F is taking me to a tool store for me to pick my goodies ;D I like it that way I get just what I want from Santa ;)
'cept no surprise ;)
My SO and my family allways hate my wish lists, since they take them to the dark and unsafe realms of tool stores, electronics stores and such places, but they get so many options that I'm still surprised (well, a little anyway)  ;D


Then off to her house and I will be kept captive for the evening. :P ;)
Ooohhh, you've been a bad boy and have to be cuffed and *Parental Advisory*
Well, enjoy your correction while it lasts.

I'll find what needs your attention next, to get the parts working together as they should.
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #174 on: December 21, 2009, 04:22:45 PM »
Goodevening Soeren

If you see this before sleep time.

Quote
That depends on what these issues are, so please do tell.


Well when I connected the Freq Gen and the rest of the circuit together, The Servo responded to the increase and decrease of the freq from the Gen circuit. Now this is where the issue part starts.

There is some kind of feedback or oscillation signal showing up on the low part of the signal to the Servo . It is very slight ~.1mv and it's pulse time is anyware from 1 to 15 ms and as you watch it on the scope the Servo reacts to it as a back and forth motion almost like the Jitters.

I not sure if it is caused by the servo load   but I switched the signal from th gen circuit back to the VRX1 and still got the same results but it was not as noticeable It seems like the B+ to the servo is having a conflict with the small signal tick that is showing up.

Sure hope you can see it in the video, it not very clear. If you watch the beginning edge of the low signal you can see the small rise.  :)
[youtube=640,505]http://www.youtube.com/watch?v=ZHeHgbtw61U[/youtube]


« Last Edit: December 21, 2009, 04:54:54 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #175 on: December 21, 2009, 04:59:44 PM »
Hi Neil,

It's sleep time here, but a couple of quick ones from the top of my head:
It might be the power the servo takes that's causing small changes in the supply, try decoupling the IC's with eg. 1nF to 100nF and perhaps more important, the servo supply as near the servo as possible with 10µF up

Another possibility is that there is a slight jitter in the signal (but again, this is most likely from the servo taking power thereby lowering the supply slightly, which then makes it a command to go the other way, back and forth).

Decoupling is most likely the cure.
(I might see more in the morning, or at least clearer - one more day at the chain gang and I'm off for the holiday... Just the thought freshens me up - Well, tomorrow is gonna be tough, as I have more patients than I regularly see in a day due to me being off for a while).


Btw. If you set the 'scope to positive trigger and adjust the trigger control (on the 'scope), you can get a (more) stable screen.
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #176 on: December 21, 2009, 10:22:03 PM »
Hi Soeren

Quote
Another possibility is that there is a slight jitter in the signal (but again, this is most likely from the servo taking power thereby lowering the supply slightly, which then makes it a command to go the other way, back and forth).

This is the case I believe as you stated. If I restrict the servo slightly with my finger and the torque increases the small signal time also increases as it is unable to switch the motor direction as easy. And the taking of power is extended before switching the servo to the other direction :P

I was searching for some info on the 3003 servo and came across a few people that were test current draw for this motor. here are there results,Re: Futaba S3003 servo current draw?

Quote
I measured two 3003's (used) with virtually identicle results.

Idle current = 26ma
Unloaded transit current = 105ma
Stall current = 430ma

at 5.1 volts. I have no 6.0 volt packs
with which to test.
I added up to 44uf in parallel with the supply right at the plug going to the Servo. But no luck on dampening it. I am going to buy a couple larger Caps to day up around 100uf or a little bigger as I believe this is where the problem is . AS you have said.

So I will leave it alone, I would hate to cook the works at this point. :o ;D

You know when you said it had been over 3 months of work on this I thought I would fall over :o It is really a wonderful thing that 2 people half way around the world never speaking a spoken word can do this.

When I was 10y/o if you had told me that some day I would be building a electronic circuit with another man thousands of miles away on a key board typing. I would have just had a good laugh :D

Hey I hope your day goes well or went well depending when you see this ;D
« Last Edit: December 22, 2009, 09:30:28 AM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #177 on: December 24, 2009, 06:00:36 AM »
Hi Neil,

This is the case I believe as you stated. If I restrict the servo slightly with my finger and the torque increases the small signal time also increases as it is unable to switch the motor direction as easy. And the taking of power is extended before switching the servo to the other direction :P
It just strikes me...
Your very neat wire placement on the breadboard might have something to say, at least in as much as it makes it a little hard to see what goes where.
If you take the supply for the voltage regulator directly from the battery and another wire directly from the battery to the rest of the circuit, both as close to the actual battery/PSU and then the caps where the wires connect on the board, it will probably help if it's the servo introducing surges through the supply.


I was searching for some info on the 3003 servo and came across a few people that were test current draw for this motor. here are there results,Re: Futaba S3003 servo current draw?

Quote
I measured two 3003's (used) with virtually identicle results.

Idle current = 26ma
Unloaded transit current = 105ma
Stall current = 430ma

at 5.1 volts. I have no 6.0 volt packs
with which to test.
I added up to 44uf in parallel with the supply right at the plug going to the Servo. But no luck on dampening it. I am going to buy a couple larger Caps to day up around 100uf or a little bigger as I believe this is where the problem is . AS you have said.
The difference between 44µF and 100µF is not all that much, but try the separate wires as described above.
That power draw alone should not create such issues if wired OK.


You know when you said it had been over 3 months of work on this I thought I would fall over :o It is really a wonderful thing that 2 people half way around the world never speaking a spoken word can do this.

When I was 10y/o if you had told me that some day I would be building a electronic circuit with another man thousands of miles away on a key board typing. I would have just had a good laugh :D
When we were 10 years old, the world was indeed a different place. I was assembling crude circuits that bears no resemblance with todays technology, computers were something that took a giant building and an army of people to feed the monster and they would take weeks to do what a modern PC does in an hour.
Most of the world were alien to a kid and today they run around texting on GSM enabled phones allways within reach... I kind of miss the possibility for getting lost in solitude (and the length of the weekends back then ;D).

Back then I wouldn't have believed much of what's possible today, least of all what I'm able to do with electronics, even if I was a tinkerer even then (fixing bicycles and minor electric work before school age), but where's the flying cars they promised?  ::)

We'll be picked up in an hour by my youngest son, since we're celebrating Xmas with him, his GF and my grandson ;D ;D ;D
In DK, we're doing all the celebrating today (the 24th) and using the 25th for playing with our toys and doing monster R&R.

Merry Christmas to you and you circles - may all your wishes come through, even if you have to wait another day :P
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

  • Robot Overlord
  • ****
  • Posts: 153
  • Helpful? 1
  • FOR GET ABOUT IT
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #178 on: December 28, 2009, 12:03:18 PM »
Hi Soeren

Hope your holiday is going well?  
I have not replied in a while as you were needing R&R and I was not wanting to interrupt for a while. I see you have stop by the forum a couple times now, so I guess I wont be rude by dragging you back to this circuit ;D

Today I will be making the the changes on the direct wire setup from the PSU to the Voltage supply to the 7805 and applying the caps as suggested. Then I will update you. how that goes.


« Last Edit: December 29, 2009, 09:37:16 PM by wheelyneil »
Take care
Neil

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Question! and Help I need to build a v8 engine servo motor governor
« Reply #179 on: December 30, 2009, 09:39:17 AM »
Hi Neil,

Hope your holiday is going well?  
I have not replied in a while as you were needing R&R and I was not wanting to interrupt for a while.
Besides a little trouble with installing a fingerprint reader, it's all good.
No need to not post. Sometimes I like to store up in my head and crunch away in the background and doing electronics is R&R to me ;D


I see you have stop by the forum a couple times now, so I guess I wont be rude by dragging you back to this circuit ;D
It's never rude posting (as long as the content isn't)  :)


Today I will be making the the changes on the direct wire setup from the PSU to the Voltage supply to the 7805 and applying the caps as suggested. Then I will update you. how that goes.
Did you try it?

I noticed a question on the pulse width, which is now edited out, but yes, 1ms to 2ms is the standard, although several manufacturers goes beyond this - if you stay within the 1-2ms you should still get enough travel on a servo, but it's just as easy to get the full travel if it's different. I don't think it will ever see the extremes though, as that would mean severely bad regulation.

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.
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

 


Get Your Ad Here