TIP142 Stepper motor driver

[crazybuoy]

I am going to build following circuit to run stepper motor using TIP142. So is there any need to change any thing in this circuit? The schematic of circuit is attached with this post.

 

[frankliner]

Each output is shorted together and to 24V?

 

[crazybuoy]

Thanks, how about the value of resistor?

 

[crazybuoy]

Now, I have try this circuit with 24V DC, 1.7Amp power supply. But still the motor does take any step (forward or backward). I think the value of resister is very much big. What it should be?

 

[crazybuoy]

Thanks guys, I have try to install 1K variable resistor and have adjust it to many values. But still the motor does not move any step. Is there any way to troubleshoot the circuit?

 

[sam185]

connect one end of motor to vcc and another to collector it will run.

---------- Post added at 03:12 ---------- Previous post was at 03:07 ----------

 

[crazybuoy]

Now following stepper driver is successful to run the steps of motor. But there is a problem that the transistors turn hot very quickly. What is problem here. I think the resistor is small. Is it?

 

[nandhu015]

where is free wheeling diodes?

 

[jorgealdo]

The value of the base resistors have nothing to do with turning hot.

Generally you want the transistors to go saturation state or cut state (switch mode).

1k is ok to drive a bipolar from a ttl (you just want to limit base current).

are you sure you are respecting the stepper motor steps ?

ah and the transistors will get hot, its ok, part of the power is dissipated throught them.

you throw four capacitors and diodes to protect the transistors.

First Stepper Circuit

ignore the microcontroller in the picture. the transistors will need heatsinks.

 

[crazybuoy]

Thanks, in First Stepper Circuit, 1N4001 is used, but I am operating the circuit at 24V, then is it right diodes to use. Or is there need to use other diodes.

 

[sam185]

if you are using 1n4001 the diode will warm up as the drop across the diode will be (23.3+23.3)V so 1n4002 is better option i think.