h bridge

I am working on making a remote controle tank using a  infrared transmiter and reciever  i can make it go forward and turn but i dont know how to make a hbridge so it can go backwards to. and im not sure what transistors to use or in what configeration.

A list of transistors and schematic would be greatly appreciated

thank you

 

it only has to be able to

it only has to be able to controle 2    1.5 v motors

This is a good place to

This is a good place to start

http://mcmanis.com/chuck/robotics/tutorial/h-bridge/bjt-circuit.html

http://solarbotics.net/librar

http://solarbotics.net/library/circuits/driver.html

Check the h-bridge matrix

Check the h-bridge matrix post for a bunch of examples.

Dan M also posted this practical and safe h-bridge design.

thank you for the links they

thank you for the links they were realy helpful

I would usually recommend

I would usually recommend using an H-bridge IC to start but I don’t know any that will output such a low voltage (1.5v).

Well, since chips like the

Well, since chips like the L293D allow you to provide a separate voltage supply for the motors, you can try it at a lower voltage and see how it works. Since the outputs on these chips typically drop about 1.5V from the Vs supply anyway, if you provide 3V in you will get about 1.5V out.

Or, you can provide 5V in on Vs (the motor supply) and getting about 3.5V out. Then use some power diodes in series to drop the voltage down to an acceptable level for the motors.

Or you could run the motors at 3.5V through the chip with 5V being supplied at Vs as described above, but use PWM so they do not run at full duty cycle.