Hello frnds..,
I am having some problem while working with ULN2003. The application desired was to run two 12v stepper motors and two 12v DC motors via the parallel port. Two different circuits were designed for the two diffrnt applications, as they were two diffrnt projects.
Pin 8 of ULN and parallel port ground were shorted with the ground of the power supply of 12v.
Pin 9 of ULN was connected to the 12v power supply.
The output from the parallel port was connected to the inputs from pin1 and so on.
All connections properly done, the ULN connected to the DC Motor circuit gave the following readings.
For logic 0 at the input: Output of ULN is 2.2v
For logic 1 at the input: Output of ULN is 0v
After 1 day:
For logic 0 at the input: Output of ULN is 0v
For logic 1 at the input: Output of ULN is 0v
I have not used ULN before but know that it works as a voltage buffer and current amplifier.
I mentioned about the stepper motors earlier, it was a circuit designed for my friends, and the stepper motor runs perfectly, sadly i didnt get to see their operation.
If anybody who has worked with ULN2003 can help me with this, it will be fondly appreciated. Though after 2 days i had to chuck the ULN's and go the conventional way of using BJT's and relays to drive the motors. But this ULN2003 has been a quest for me all the time. I dont why it gave me all the problem in the world., and my frnds not. I changed 6 ULN's before giving up.
Sorry for the long question, but was actually frustrated on not able to make such simple things work.
Dilu
I am having some problem while working with ULN2003. The application desired was to run two 12v stepper motors and two 12v DC motors via the parallel port. Two different circuits were designed for the two diffrnt applications, as they were two diffrnt projects.
Pin 8 of ULN and parallel port ground were shorted with the ground of the power supply of 12v.
Pin 9 of ULN was connected to the 12v power supply.
The output from the parallel port was connected to the inputs from pin1 and so on.
All connections properly done, the ULN connected to the DC Motor circuit gave the following readings.
For logic 0 at the input: Output of ULN is 2.2v
For logic 1 at the input: Output of ULN is 0v
After 1 day:
For logic 0 at the input: Output of ULN is 0v
For logic 1 at the input: Output of ULN is 0v
I have not used ULN before but know that it works as a voltage buffer and current amplifier.
I mentioned about the stepper motors earlier, it was a circuit designed for my friends, and the stepper motor runs perfectly, sadly i didnt get to see their operation.
If anybody who has worked with ULN2003 can help me with this, it will be fondly appreciated. Though after 2 days i had to chuck the ULN's and go the conventional way of using BJT's and relays to drive the motors. But this ULN2003 has been a quest for me all the time. I dont why it gave me all the problem in the world., and my frnds not. I changed 6 ULN's before giving up.
Sorry for the long question, but was actually frustrated on not able to make such simple things work.
Dilu