Connect cathode of bootstrap. So keeping a coil energized for a long period of time is basically leaving a short circuit. The motor coils are essentially an inductor, which resists sudden changes in current flow. Thanks for the reply guys.
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Nov 05, , am The H-Bridge looks pretty standard. Usually any extra circuitry is to protect the Arduino from back-EMF. The motor coils are essentially an inductor, which resists sudden changes in current flow.
If you suddenly switch off the power, there will be some residual current in the motor coil which attempts to continue to flow. Otherwise your ground floats and the noise in the circut causes the motor to vibrate. The noise is actually turning on random channels for very brief moments randomly.
Your H-Bridge is ok to get warm Check the specs in the datasheet. It says it can go up to degrees C, but it should never get anywhere near that. The motors, however, should not be getting very warm.
The datasheet says it could increase 80 degrees C at maximum. When the coils of the stepper motor are un-energized, the motor should spin freely. However, if you leave one of the coils energized, there will be resistance when you try to spin the motor shaft by hand. There must be current flowing to maintain the field. Usually motor coils do not provide very much resistance.
Usually less than 50 ohms. So keeping a coil energized for a long period of time is basically leaving a short circuit. The motor datasheet says you can use up to a max of mA per phase in the motor coils. But, with 4-wire stepper motors, you never have all 4 channels active at the same time. It can be driven in full-step or half-step, which is essentially saying that you drive the motor with just 1 phase at a time, or 2 phases at a time.
At any rate, you should be fine, the H-Bridge should be able to handle that motor. One other issue is that you could have your motor coil lead wires mis-matched. That can cause the motor to stutter-step or to step only at certain resonant frequencies.