Topic: USB DAC WARNING !!!

[James]

It has come to my attention that some people are experiencing problems while using a modified USB sound card.

These problem come from hot-plugging the USB.

In three words...

Don't do that!

Your computer should be up and running with the USB DAC plugged in, recognized and in the control of its Windows driver (set to the right number of channels) BEFORE any connected laser equipment is powered up.

All of the connected laser equipment should be powered down BEFORE you unplug the USB or shut down the computer.

James. 

[dar303]

Been there, done that! The galvos goes *KLONK*!
A quick fix would maybe be a couple of relays that ground the X/Y & blanking signals through a resistor when 5V from the USB isn't present. One relay usually have two poles so it shouldnt take too much room with 2 or 3 relays since they can be very small.
Or just use analogue switches instead.

[James]

Read this:

http://akrobiz.com/laserboy/forum/index.php/topic,212.0.html

Pat did a bang-up job figuring all this stuff out!

You should have a lot less to worry about!

James.