Help me draw this circuit's diagram

[mosfet66]

Hello,
Some time ago I made me build the attached circuit. It's a speed controller for 12 V dc motor. The problem is that I want to rebuild it for another project but there are some part of the circuit I don't understand. Can you please help me drawing a diagram for it? The only things I know are: the pot resistance 20K, the diode is a By255, the mosfet transistor is irfp054 and the IC is a lm324.

 

[CDRIVE]

Post a link to the webpage that you originally found it.

Chris

 

[Minder]

You don't neccesarily need to know how it works if you accurately reverse engineer it this entails drawing out a schematic by very carefully following every connection.
Post what you have here and it can be looked over and checked.
There does not seem that many components.
M.

 

[CDRIVE]

In the event that you don't remember where you got it take a look through all of these LM324 PWM Motor Control schematics. Odds are you'll find yours or many very similar designs.

Chris

 

[mosfet66]

In the event that you don't remember where you got it take a look through all of these LM324 PWM Motor Control schematics. Odds are you'll find yours or many very similar designs.

Chris

I bought it in a shop in my town, it does have a site, but there's not a diagram there (not even a good pic actually). I'm going to have a look through the schematics you send me, good idea.

 

[Alec_t]

According to post #1 you built the circuit. Now you say you bought it?

 

[Martaine2005]

You did a great job of "beefing up" the high current path with solder!
Surely you can remember with such few components..
Any how, a diagram would look identical to what you have as Minder said "follow the lines"

Martin

 

[mosfet66]

According to post #1 you built the circuit. Now you say you bought it?

I'm sorry, I actually wrote wrong, I meant I had someone built that circuit (I paid for that).

 

[mosfet66]

You did a great job of "beefing up" the high current path with solder!
Surely you can remember with such few components..
Any how, a diagram would look identical to what you have as Minder said "follow the lines"

Martin

Even if, as i said in the last reply to Alec_t, i didn't build the original circuit in the pic, i suppose that following the lines is the best alternative. Thank you to all.

 

[Martaine2005]

I'm sorry, I actually wrote wrong

Don't worry translators often get it wrong.....You had no excuse for the Alfasud though!!

Martin

 

[Minder]

They exist on ebay for $5.00 based around the 555 and PWM control or see
http://www.discovercircuits.com/DJ-Circuits/simplepwm2.htm
M.

 

[CDRIVE]

Hey guys, lets not be elitists and badger mosfet66. I think we can all agree that we are by far the friendliest electronics forum in the world. Let's keep it that way.

M66 please do as advised and give a go at reverse engineering the PCB. Then post what you drew. We can then attempt to correct obvious errors. I'll even redraw it for ya with computer graphics.

Also,... please post your name. We all have handles here but we're all humans (except for Marty??? ) and we address each other by our given name.

Marty's Uncle Chris

 

[davenn]

Thanks for that post, Chris
its appreciated


Dave

 

[davenn]

(except for Marty??? )

uh huh, we suspect he's a Martian Marty

 

[CDRIVE]

Thanks for that post, Chris
its appreciated


Dave

Dave, it's getting close to Christmas. I get all gushy and fuzzy at this time of the year. I think of all the family and friends that I've lost through the years. Two weeks ago I lost my Mom at 92. She always said "If you don't have something nice to say don't say anything at all". I confess that I've not always followed that tenant but it's worth always trying to.

EP is a very special place. I consider many here my friends that are sadly separated by distance and oceans. When I'm here I feel welcomed and missed when I'm not.

One last note. If any one of us has aspirations of being considered the keystone member of EP all they have to do is emulate Kris Blue. Even evasive posts that grated on the best of us never raised his ire or changed his mellow tone. I do miss him so very much.

Chris

 

[davenn]

Dave, it's getting close to Christmas. I get all gushy and fuzzy at this time of the year. I think of all the family and friends that I've lost through the years. Two weeks ago I lost my Mom at 92. She always said "If you don't have something nice to say don't say anything at all". I confess that I've not always followed that tenant but it's worth always trying to.

Sorry to hear that buddy ... my condolences
and those are wise words to live by

EP is a very special place. I consider many here my friends that are sadly separated by distance and oceans. When I'm here I feel welcomed and missed when I'm not.

yup

One last note. If any one of us has aspirations of being considered the keystone member of EP all they have to do is emulate Kris Blue. Even evasive posts that grated on the best of us never raised his ire or changed his mellow tone. I do miss him so very much.

and another yup ... agree totally

Dave

 

[mosfet66]

... please post your name. We all have handles here but we're all humans (except for Marty??? ) and we address each other by our given name.

Marty's Uncle Chris

I'm Marco, Nice to meet you all. I'll work on that pcb when i'll be home, hope soon.

Dave, it's getting close to Christmas. I get all gushy and fuzzy at this time of the year. I think of all the family and friends that I've lost through the years. Two weeks ago I lost my Mom at 92. She always said "If you don't have something nice to say don't say anything at all". I confess that I've not always followed that tenant but it's worth always trying to.
Chris

My condolences, I'm so sorry for your loss.

 

[73's de Edd]

.
.


Sir mosfet66 . . . . . .

I tell you whuts . . . . .since your fotie-grafs definition/focus was being somewhat less than perfect on the reeee-sis-tom-er-fers marked values.
But . . .HEY . . .I CAN make out the series drive resistor to the Mosfet gate as being 1 K.

However . . . . . . since YOU are able to see ALL of its parts . .you will be able to fill us in..

This would be the first stage towards generating a schematic for your circuitry . . . . .

Get an ohmmeter and check out Zero ohm paths of the "hidden" foil paths under the LM324 of the red circled points.
The Red Star looks like it connects to pin 7, but does it connect to any other LM324 pin also ?
Plus also check every pin of the LM324 to see if there also might also be OTHER hidden interconnects to other pins on it, to be sure.
Seeing my yellow arrows and the fact that the output of an LM324 op amp OUTPUT section is being directly connected to its NON INVERTING input,
with pins 8 to 9 tells me that particular section is being used for a voltage referencing or halving function.
The left mystery ceramic ? capacitor is probably used as a summing function and is up in the 10-47 nf range and is VERY likely unmarked.
While the right ? is probably the frequency determining C portion of a R/C oscillator and you just might find its value marked on its other hidden side.
(Or that COULD possibly be a like film reee-sistor, that just got mounted upside down ? )
You seem to have the speed pot connected with 4 wires, do I have it correct, with one wire possibly being a redundant connection ?
Plus, with it having trim resistors on either end of it, is suggestive of an optimally "sweet spot adjustment range".

Give some feedback on that requested info . . . . .

Your reference . . . . . . .Marked up:

73's de Edd



.




.

 

[CDRIVE]

Hi Marco and thank you.

On a cheerer note the always helpful EP family is working hard for you. It would appear that Edd was already dissecting and labeling your circuit as we spoke.

Chris

 

[mosfet66]

.
.


Sir mosfet66 . . . . . .

I tell you whuts . . . . .since your fotie-grafs definition/focus was being somewhat less than perfect on the reeee-sis-tom-er-fers marked values.
But . . .HEY . . .I CAN make out the series drive resistor to the Mosfet gate as being 1 K.

However . . . . . . since YOU are able to see ALL of its parts . .you will be able to fill us in..

This would be the first stage towards generating a schematic for your circuitry . . . . .

Get an ohmmeter and check out Zero ohm paths of the "hidden" foil paths under the LM324 of the red circled points.
The Red Star looks like it connects to pin 7, but does it connect to any other LM324 pin also ?
Plus also check every pin of the LM324 to see if there also might also be OTHER hidden interconnects to other pins on it, to be sure.
Seeing my yellow arrows and the fact that the output of an LM324 op amp OUTPUT section is being directly connected to its NON INVERTING input,
with pins 8 to 9 tells me that particular section is being used for a voltage referencing or halving function.
The left mystery ceramic ? capacitor is probably used as a summing function and is up in the 10-47 nf range and is VERY likely unmarked.
While the right ? is probably the frequency determining C portion of a R/C oscillator and you just might find its value marked on its other hidden side.
(Or that COULD possibly be a like film reee-sistor, that just got mounted upside down ? )
You seem to have the speed pot connected with 4 wires, do I have it correct, with one wire possibly being a redundant connection ?
Plus, with it having trim resistors on either end of it, is suggestive of an optimally "sweet spot adjustment range".

Give some feedback on that requested info . . . . .

Your reference . . . . . . .Marked up:

73's de Edd



.




.

Thank you for the answer, i'll test the missing resistances as soon as i can (I'm at the university in this period). Hope to give you soon further informations.