recommended DC H-bridge?

[BANE]

Hello, i was just looking a making my own h-bridge when i discovered this onehttp://www.hobbyengineering.com/H1918.html

Has anyone used this one before or know how well it would work controlling two large printer motors?

Bane

[bens]

That depends on how much current your printer motors draw, and are they DC brushed motors or stepper motors?

[BANE]

there DC (not sure if brushless) and they draw about 800 mAh each (i tried them out on a 1.6 mAh bat and they work well)

Bane

[ALZ]

If the motor runs at 800 mAh then that h-bridge can not be used. A stall motor would take 5 to 10 times more current. The h-bridge can only handle 4 amps. In real life 2 amps would be more like it.

http://robotics.scienceontheweb.net

[bens]

they draw about 800 mAh each

Is this stall current or no-load current?  If it's the latter (which I'm guessing it is since you describe these as large motors), what is the stall current?

- Ben

[BANE]

Does anybody know of a good website that has printer motor specifications?

Bane

[bens]

If you have a multimeter you can just hold your motor stalled (i.e. don't let it spin) and measure the current through it at a specific voltage.  Stall current will pretty much vary linearly with voltage.

- Ben