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Topic: Flyback diode on DC motor schematic please (Read 4 times) previous topic - next topic

AWOL

If it is decent controller (you haven't said what you're using) it will have diodes built-in.

See here
http://www.robotroom.com/BipolarHBridge.html
for a guide to H-bridges and snubber diodes.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

AgeingHippy

Hi AWOL

Thanks for the link. That was exactly the sort of thing I was looking for.

I am currently using the SN754410NE quad half h-bridge driver to learn how to drive motors....

Looking at the schematic of outputs it looks like it has diodes...

Again, thanks for the link. I understand now that a diode has to run from each motor wire to Posative and from GND to each wire, making a total of 4 diodes per motor.

Aeturnalus

The SN754410NE's internal diodes are NOT flyback diodes - they're incapable of sinking the required current.  You'll need to add external ones as well.

AKSoapy29

I didn't read all the posts here, but I want to point you out to my website were I made instructions for how to run a dc motor. Here's the link: http://aksoapy29.comoj.com/dcmotorcontroller.html
Andrew K.

AWOL

#9
May 22, 2011, 08:19 pm Last Edit: May 22, 2011, 08:30 pm by AWOL Reason: 1
Quote
I didn't read all the posts here,

Specifically, you didn't read the bit about reversing the motor.

Interesting circuit diagram - remind me again, which is the base, the emitter and the collector?

Code: [Select]
int potpin = A0;
int val;

void setup() {}

void loop() {
val = analogRead(potpin);
val = map(val, 0, 1023, 0, 225);
analogWrite(3, val);
delay(15);
}


Don't you ever want to run the motor at full speed?
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

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