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H-bridge motor driver need help here

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Member level 2
Jun 3, 2009
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h bridge transistor motar driver cct

Please take a look at this link,

If i exchange the Transistor of PNP into NPN.
The operation is change into

R1= GND, R2= Vcc, R3= VCc ,R4 =Gnd
R1= Vcc, R2= Gnd, R3= Gnd ,R4 =Vcc

The problem, i facing at this moment is that when the transistor is on, The transistor cannot endurance for long period due to the heat. The transistor that i been using in the circuit is NPN(2N2222A). The resistor connect to the each of the Transistor is 1k ohm.
The Voltage supply to this circuit i use is 5V, the input volatge to each transistor also 5v(when need it).

But i exchange the resistor into 100 ohm to each Transistor(base), it seems to be last long a bit, but also cannot endurance for long period, the transistor will heat up and burn....

I need help here. please reply the solution step by step tq.

hbridge transistor driver

Now i change the circuit a bit.
IF the motor is forward condition the current in the circuit it might look like this.
please tell me/say out if my theory is wrong!

And please tell me wheather this circuit can be work or not. It is just theoretical solution.


what is the need for motor driver

If the transistor is burning, it probably is not the correct one to be use, you need a transistor that can handle more power.
bridge motor drive

Thx for reply me....

Finally i find out the way to solve the problem already....

please give some opinion ya...

well, ericyeoh

What I would do is to make the base resistor bigger than the value 1Kohm because as the base resistor gets bigger, the current entering the base goes smaller so the transistor would endure longer time.
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