Hi everyone,
I've got a question, I built H-Bridge driver for my motor from this site(Electronic Projects) and I want to conect it to basic stamp II.
I used two 2N3055 transistors and 2 diodes on the ground to switch the inputs, and everything was ok when i assembled it on my breadboard (with 4.7 volts, which is almost the same as output form the basic stamp)but after I've connected to the basic stamp it didn't work as it should, actually it could change the direction but the motor didn't get as much power as it schould. Does anybody have an idea how to fix it.
thanks for reading this

 

You can't build an H-bridge with just two transistors?, also a 2N3055 is a very low gain device, you can't feed it directly from a PIC pin.

Try posting the circuit you are using.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

I used 4 transistors for the H-Bridge, those 2 2N3055 are for the driving the h-bridge from the basic stamp II and I used schematic from this site.

 

this is the circuit of the h-bridge, I used 2 2N3055 as switches

Attached Images

dc_motor_control_circuit.gif (9.7 KB, 1749 views)

 

how are you going to ensure you have enough voltage to switch-on the top BJT's ? you are useing NPN's and no bootstrapped/floating gate supply

 

As I said previously, a 2N3055 is a very low gain device, you can't feed it from a PIC.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

so, what can I use to drive this circuit from Basic Stamp,
thanks for replay.

 

Logic level MOSFETs work much better. They have loads of gain, fewer components, and run much more efficiently & cooler.

 

Can you give mesome examples of Logic levels MOSFETs,
like part number or whatever, I'm going to do some researches also, thanks

 

Oznog wrote this earlier

 

what u can try is a simple high value resistance in paralel with motor...
that would increase the speed to some extent