TTL for shutter. Can't get it to work correctly, any ideas?

[jayDC]

Okay heres where I'm at:

I'm currently in the process of building my first laser projector. I have my scanners working, and the beam table I engineered, but the problem is with getting the shutter to work. I'm using a 12vdc 900mA power supply, a 12vdc ledex solenoid, a 12vdc 2amp relay with a 5vdc 42Ohm coil.

When I apply 3vdc @ 100mA to the relay coil, it snaps and the shutter works, although when I connect it to the TTL line of my DAC card, the relay does not work.
I have also tried a 30vdc 2amp relay with a 4.5vdc 145Ohm coil, with the same result.

Any ideas?.. Thanks for the help..

[marconi]

Hi jayDC...Welcome Aboard

Looks like you will need to find a driver for the relay.

One possible way is to use some discrete components like a darlington transistor and a few resistors..with a separate power supply ,
prolly +5 but a few extra volts wont hurt...
..the resistors are for current limiting..etc..
Another way would be to use a Darlington Array IC chip..like for example ULN2003.or just about anything in this family.
It is made specifically to drive relays , lights ., leds...or other current hogs. ...directly from a low current source like the TTL output of your PC...

I'd look up simple relay driver circuits on the internet... you'll find a slew of stuff..

Good luck with your project...

[taggalucci]

You have no need to worry about these shutters some time they create problem but you just off your shutter and
return on after 5 or 10 minutes i hope you remove your problem

Woah, I'd hope he's sorted out his problem since it was reported over 7 (SEVEN) years ago! Nice of you to be concerned and all...