View Full Version : stepper - voltage drop

12-31-2004, 04:17 AM
I am using one stepper at 12v with uln2003 as driver

when i check the supply voltage without motor it shows 12v
But when steppers r running supply voltage shows 9v...............
When i run 2 steppers the supply voltage shows 8v
why is this voltage drop?
my steppers r at fault? or the stepper driver?

I am giving +12 to common and control the rest 4 wires with
(1000), (0100), (0010), (0001) ie. with a +5v in rotation to the 4 coils.
Current of about 65mA is used by the stepper at 12v voltage.
It rotates at max speed of 65 revolutions/minute (200 steps/revolution)
Is this speed of rotation fine? or is it too slow for a micromouse.


12-31-2004, 09:24 AM
I think your power supply is getting loaded .... check it

01-01-2005, 02:41 AM
Its just the microcontroller and one stepper i am driving with the i/p power. I am giving the input power from an adapter(500mA).
and the current used by my circuit is not exceeding 200mA.
.....so if i am right ...the circuit requirement is less than what the adapter can source......??????????? what else could be the problem?

01-02-2005, 12:07 AM
Hey sumandeep thankyou for replying......i checked the i/p given through the adapter....more the current pulled byt the circuit....more is the voltage drop....there is something wrong with the adapter and not the circuit or the motor....