Thanks for your reply.Here is the motor that worked:Pololu Mini Metal GearmotorFeatures:• DC Motor• Nominal Voltage: 6V• Free RPM: 140• Stall Torque: 15 oz-in (1.0 kg-cm)• Stall Current: 800mA• Reduction: 100:1• Size (mm): 1.66" x 0.46" x 0.60"• Weight: 0.80oz / 27g
Also, I couldn't find the datasheet for the 'Tamiya USA 540 Motor' as it came with the RC chasis. But it should be similar to what you posted.
And I believe you. I think the motor's pulling too much current saturating the H-bridge. (Multimeter shows 2.15 A for a sec then it goes away >> way beyond the H-bridge capability)
Any suggestions on how I can decrease the current going into the motor to about 1 A. The thing is, the '540 Motor' fits perfectly on the chassis but the Polulu is like one quarter the size of '540'. So, if possible I would like to use the "540" and avoid more assembly work. Another fact, the speed of the Polulu's revolution speed is perfect for our project but the "540" spins at an insanely high speed (due to high voltage/current ??).
I am going to dedicate today to running the "540". If you have a suggestion for a better H-bridge (and available at Radioshack so that I can get it quick: I cannot wait a week so I can't order it online) please provide. Otherwise, I will have to switch to the Polulu.