Alternative to DB25 switchover box using ILDA Interlock

[liteworx]

So, I have two lasers running from 1 x FB3, I was considering buying a DB25 switchover box (like the old printer switchs) but as I have read not all of these switches actually switch all 25 pins, also the switchover box would only allow me to output to either projector and not give the option to send the ilda signal to both projectors if required,

I was therfore wondering if I could make my own switch box to control the ilda interlock loop for each projector as follows

Switch 1 - SPST - Interlock Loop - Projector 1
Switch 2 - SPST - Interlock Loop - Projector 2
Switch 3 - SPST - Interlock Loop - FB3

This way I could enable / close Switch 3 - Lets call that my master interlock

Then I could enable / close Switch 1 - To Enable Projector 1 or enable / close Switch 2 - To Enable Projector 2 and then have the ability to blackout both projectors buy disabling / open Switch 3

Obviously all other ilda connections would be connected straight thru like X,Y,R,G,B

Would this work ??

Thanks
Dave

[polishedball]

The 5 old style boxes I own have large rotary switches that do change over all the pins.

So, I have two lasers running from 1 x FB3, I was considering buying a DB25 switchover box (like the old printer switchs) but as I have read not all of these switches actually switch all 25 pins, also the switchover box would only allow me to output to either projector and not give the option to send the ilda signal to both projectors if required,

I was therfore wondering if I could make my own switch box to control the ilda interlock loop for each projector as follows

Switch 1 - SPST - Interlock Loop - Projector 1
Switch 2 - SPST - Interlock Loop - Projector 2
Switch 3 - SPST - Interlock Loop - FB3

This way I could enable / close Switch 3 - Lets call that my master interlock

Then I could enable / close Switch 1 - To Enable Projector 1 or enable / close Switch 2 - To Enable Projector 2 and then have the ability to blackout both projectors buy disabling / open Switch 3

Obviously all other ilda connections would be connected straight thru like X,Y,R,G,B

Would this work ??

Thanks
Dave

[taggalucci]

I wouldn't use the interlock signal to blackout your projectors. The shutter signal is really for this purpose.

You could put a switch inline to each projector after splitting the ILDA signal. This relies on your projector responding to the shutter signal, either with a mechanical shutter or by cutting off the signal to each laser.

Interlocks should be wired in such a way that reconnecting them doesn't cause the lasers to come back on immediately. The projector should need to be "reset" after an interlock failure and then require a conscious start e.g. via pressing run button. This would prevent your suggestion from working.

Also, if you wanted to chase the lasers, you are better off doing this by switching the modulation signals rather than just turning the whole lasers on and off. This could cause damage depending on the type of laser as the TECs and fans would also be turned off.