Author Topic: 5V regulator... wich pin does what ? re 50$ robot  (Read 1563 times)

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Offline rabadswompeTopic starter

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5V regulator... wich pin does what ? re 50$ robot
« on: February 13, 2011, 10:45:15 AM »
With the "metal tab" resting on the table and the migddle pin being Ground... what are the left and right ones ?

Is it

Input-Grnd-5v output

or

5v output-grnd-input

edit- found this in an instructable... see attached picture.

I think I mixed up Webbot and Iadmin's wiring... I mean I soldered in the 5v regul Admin's way but constructed the whole circuit Webbot's way (as per the pdf diagram) where the 5v regul seems "backwards.

Soooo... I guess That's the problem I'm getting and that , while tab is flat on table, the pins really are 9v in-grnd-5v out
Can anyone confirm?

« Last Edit: February 13, 2011, 10:56:45 AM by rabadswompe »

Offline waltr

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #1 on: February 13, 2011, 11:44:07 AM »
If the regulator is an LM7805 then yes from left to right is: In-Gnd-Out

Google works very well for finding data sheets to parts so you can verify pin-outs etc.

Offline Webbot

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #2 on: February 13, 2011, 12:38:56 PM »
I think I mixed up Webbot and Iadmin's wiring... I mean I soldered in the 5v regul Admin's way but constructed the whole circuit Webbot's way (as per the pdf diagram) where the 5v regul seems "backwards.


Moral of the story is to follow one design or another. Don't assume that two different designs are based on each other  :)

Know that you are thinking of starting again - in which case you may find my tutorial here http://www.societyofrobots.com/member_tutorials/node/193 to be useful. Its for a different PCB design but the steps are still valid. Aplogies that is splattered in strange <!-- tags - wrote it in Word and uploaded it !
The essence of the tutorial is not to rush stuff. Keep measuring, checking at every step.
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline rabadswompeTopic starter

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #3 on: February 13, 2011, 05:18:39 PM »
Thanks Webbot... I'll go read it and plow on!

If the saying "if your not making mistakes, then you're not trying" is valid...well, I'm trying real hard ;D

Edit: I understand things better now. My frustration came not from the design and its originator(s) but fro my inability to correct myself. Thanks for the link to your tutorial Webbot! I've learned!
« Last Edit: February 13, 2011, 08:01:06 PM by rabadswompe »

Offline dmclifton

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #4 on: February 14, 2011, 05:56:47 AM »
With the "metal tab" resting on the table and the migddle pin being Ground... what are the left and right ones ?

Is it

Input-Grnd-5v output

or

5v output-grnd-input

edit- found this in an instructable... see attached picture.

I think I mixed up Webbot and Iadmin's wiring... I mean I soldered in the 5v regul Admin's way but constructed the whole circuit Webbot's way (as per the pdf diagram) where the 5v regul seems "backwards.

Soooo... I guess That's the problem I'm getting and that , while tab is flat on table, the pins really are 9v in-grnd-5v out
Can anyone confirm?



Yeah, I also noticed that the pdf has the regulator backward from how Admin has it in his layout, but there is no statement to that effect. I left a comment about this on the bottom of the thread.

Offline rabadswompeTopic starter

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #5 on: February 14, 2011, 09:33:27 AM »
Webbot gave me a good lesson! Again, many thanks!!!!!!!

It is soooo wrong to assume that Admin's design and Webbot's are identical...they are not. Go with one or the other ...you can't go between. I thought Webbot's was easier to read for me (I know little about electronics).

I flipped the 5v regulator so that the plastic(black) side faces the capacitor (again, like in Webbot's pdf ). I also had a small short at the MOSI pin of the ISP. (easy fix)

Once these 2 things were done, I turned on the juice, connected the ISP, uploaded the hold_servo.hex and VOILA... servos were spinning .

I'm a happy camper again!
« Last Edit: February 14, 2011, 09:35:05 AM by rabadswompe »

Offline Soeren

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Re: 5V regulator... wich pin does what ? re 50$ robot
« Reply #6 on: February 17, 2011, 09:30:50 PM »
Hi,

[...] uploaded the hold_servo.hex and VOILA... servos were spinning .
Doesn't sound much like a "voilà moment" to me  ;)
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

 


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