Menticol
Active Member
Hello again guys!
I'm having some problems with my parallel port + ULN2803 setup. When I connected my stepper motor all the coils were continuously activated, no matter the status of the parallel port pins.
The problem repeats using another ULN2803, a resistive load (12 light bulb) and a +5v power supply for the controlling pin (replacing the parallel port signal). Result is the same, bulb keeps continuously ON. Connecting or disconnecting the control pin just increases the bulb brightness a little bit.
Attached is the schematic of what I'm trying to do. Any help will be extremely appreciated.
I'm having some problems with my parallel port + ULN2803 setup. When I connected my stepper motor all the coils were continuously activated, no matter the status of the parallel port pins.
The problem repeats using another ULN2803, a resistive load (12 light bulb) and a +5v power supply for the controlling pin (replacing the parallel port signal). Result is the same, bulb keeps continuously ON. Connecting or disconnecting the control pin just increases the bulb brightness a little bit.
Attached is the schematic of what I'm trying to do. Any help will be extremely appreciated.
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