NPN Motor Driver Circuit

[Canabots]

Hey,

Can someone here recommend me a basic bi-direction motor driver circuit that only uses NPN transistors such as 2N3904 or 2N2222 or other compatible versions?

This is for 2 small motors (tiny, infact) operating around 2.4 volts. I plan on receiving the output from a microcontroller. The motors run off a battery of 2.4V at 70mAh.

I've tried a few, but none of them have worked so far.

Thanks in advance!

PS: Incase you're curious, these are from a ZipZaps car

[Canabots]

Arg, I worded that a little wrong.

I want is a reccomendation for a really simple motor driver circuit, and it ca use PNP/NPN transistors.

I can only control it using a positive voltage output.

Thanks

[MaltiK]

port B is obviously the output

[Canabots]

I've already used motor drivers like that, but unfortunately, it's only a single directional motor driver. The project I'm doing requires a bi-directional motor driver, unfortunately, of which I've tried a few, but without luck

Thanks anyhow!

[fuzzyt]

If you can use both NPN and PNP, have you looked at a standard h-bridge?

http://www.robotroom.com/BipolarHBridge.html

[Canabots]

The issue with that one, though, is that it requires being connected to GND, but I need to control it through a microcontroller output. Unless there was some was we could connect it to GND...

Would it be possible to place another NPN transistor there and have it connect the PNP to GND once a signal is sent to it? I think I'll try that out.

Canabots

[paulstreats]

Whatever you use will need a connection to a common gnd or the signal from the mcu wont work...

[Canabots]

Hmmm,
I just threw together this schematic, to demostrate my idea.

It is attached to this post. I sort of threw it together quickly, so I now I'm missing resistors and such, but I just wanted a general idea.

So would it work?

Canabots

[Soeren]

Hi,

Try this: http://That.Homepage.dk/PDF/H-bro_TO-92.pdf
With such low voltage, I'd suggest transistors from Zetex, since they have some with very low U_CE. Another solution would be to up the voltage a bit, just enough to counter the drop in the transistors.
 

[Admin]

http://www.societyofrobots.com/schematics_h-bridgedes.shtml