I am using a 12v/8amp power source to supply three servos, two steppers, three dc motors, and twenty LEDs. A DC to DC converter will provide step down, 6v source for the servos, but the DC motors are a problem. I have tried an SN754410, connecting it as described in http://www.uduino.com/tutorials/11, but the chip overheats immediately. Assuming the current was beyond specs, I used an LM317 in current limiting mode, bringing it down to about one amp with the same results - very hot, very fast. Power supply continues to be an ongoing puzzle. Any advise would be appreciated.
At 1A you’re operating the H bridge at it’s limit. I’d expect it to get “hot”. 65C is hot enough you can’t keep your finger on it long. How hot is your IC ? What are the motors you’re using ?
Are the stepper motors running? If so, I’d expect it to get warm, but not “very hot, very fast”. If not (or you haven’t got that far), it sounds like you may have a wiring fault or damaged chip.
MichaelN:
Are the stepper motors running? If so, I’d expect it to get warm, but not “very hot, very fast”. If not (or you haven’t got that far), it sounds like you may have a wiring fault or damaged chip.
Or the motor are too large (draw more than the SN754410 can supply).
Exactly which motors are you using with the SN754410? Link to motor data sheet is helpful.
How is the chip and the motors wired?