BS2 - 12V Solenoid

Boris711

Hello All,
This is probably a simple problem for someone other than myself.

I have a BS2 mounted on a BOE USB Rev D that I am trying to use to actuate a 12V DC Latching Solenoid.· I have a Darlington array (ULN2803A) in between the BS2 and the solenoid.· P3 from BS2 is attached via the X2 connector to B6 on Darlington, + solenoid is connected to C6 on Darlington, - solenoid connected to·Vss. I believe the hardware is all good, as I am able to actuate the solenoid·straight from my 12VDC power source.· And I can·attach a stepper motor to Out side of the Darlington and·actuate the motor.· Now, I've tried to actuate the solenoid with both·5VDC directly off the·BOE thru the Darlington·and with the external 12VDC source connected - to pin9 ·+ to pin10, neither got any movement.· Also, I have tried connecting - solenoid to C6 on Darlington and + solenoid to Vdd, still no happiness.

So, these questions,·I believe, should get me on the right path:

What is the correct way to wire the solenoid to the Darlington/board?
What is the correct way to attach the 12VDC to the Darlington/board?

AND, the biggie:
Can someone provide a quick coding sample to verify operation?

From there I should be able to muddle through.·

I·have attached photos that might help,·I don't have a schematic at the moment.

TIA!
Jeff

KelvinL

The ULN2803A may not provide enough current to drive your solenoid, a solenoid could possibly suck up over 500mA easily. You should know first how much current to keep the solenoid working, then pick a power enough Darlington transistor to work on it. Or you may try using 2 units in pair to provide current in double if your solenoid consumes current less than 1A.

I always use Optio-isolator to protect Basic stamp when driving solenoid, be sure not to share same power source in between stamp and solenoid.

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Kelvin Liao