GM20s

[allthatwhichis]

That question I'll let some one else answer because I dont understand electronics and I dont use these for shutters anymore. I hire an Ethiopian to jump in and out of the beam path on command. (send hatemail to www.danielbriggs.com)

At least you pay huh?

[Laserman532]

8 kits left. If these dont sell I will move them over to www.microlaserlabs.com and increase the price to around $140.00. So get them now and save $$$$$$$

[mccarrot]

Can they be used as a safety shutter? or are there better (cheaper ) solutions for shutters?

[mixedgas]

Can they be used as a safety shutter? or are there better (cheaper ) solutions for shutters?

Gm20 is the shutter or fast beam table actuator of choice. Get them while you can , GSI is stopping production.

My projector has 4 for beam effects and two for shutters (argon laser, krypton laser)

Steve

[buffo]

Assuming I purchase said kit, or attain a GM20 by other means; do I need an amp or driver of some sort to do the 'shuttering' ?

Yes. Most people drive them with a simple darlington transistor pair. DZ has a circuit that he's posted before... I'll see if I can get him to post it here. It's really very simple though.

And Steve is right - this is probably the best component to use for a shutter. It's also the defacto standard in the business...

Adam

[allthatwhichis]

[DZ]

Here is the circuit that I use in my projector. Because I'm running my shutter on only 5V, I needed to add a relay to get just enough swing from the GM-20 to unblock the beam. Otherwise, you'll loose some voltage on a darlington transistor. I don't remember exactly what value I used for the capacitor that's in parallel with the GM-20, it may have been 10uf or something close to that, basically, it's there to eliminate a bouncing effect that you'll see without one there. Enjoy!

[Laserman532]

BUMPED FOR "6 Left" announcement

[buffo]

David;

Don't you think the 2n2222 has enough grunt to drive the GM-20 directly? Why add the relay if you don't need it?

Adam

[DZ]

Don't you think the 2n2222 has enough grunt to drive the GM-20 directly? Why add the relay if you don't need it?

It could probably run it just fine, though you'd probably want to cascade two of them for the darlington effect, or just use a TIP122 darlington transistor. The problem with that is the voltage loss across the transistors, I needed a full 5V for my GM20 to clear the beam path and the relay provides the full 5V. It really just depends on your configuration, a shutter can be setup in so many different ways.