frying eggs with a ULN2003
On Thu, 1 Mar 2001 20:46:15 -0000, you wrote:
>>>I am driving a stepper motor -with 3 windings (4 Ohms each) and
>>>1 common terminal- salvaged from an old disk drive by means of
>>>explained by means of the electric power formula :
>>> W = V**2/R = 12**2/4 = 36W !?!?
>That´s the whole power you are sinking from the supply. As the 2003 is an open collector transistor, when it is driving the windings the voltage across it is about 0.2 volts,
>so the power the transistor is disipating is V*I = 0.2*3 = 0.6 W
Wrong, the 2003 is a darlington, which will drop at least 0.6V,
therefore it will get VERY hot at 3A.
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In reply to: <200103012046.UAA21946@chantada.ll.iac.es>
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