You may want to use a different DPDT center off switch. There are ones with a 'detent' at the center. You have to pull up to get the switch out of any of the three positions and move to the other position. That type of switch will probably not have this issue.
I actually think you just hit the nail on the head there. When I switch back to the OFF position as slowly and deliberately as I can, this problem no longer occurs. I may have to source a different DPDT switch if this problem persists with the other switches I have (of the same model, I ordered 10 originally), but I think the wiring is now correct. I really appreciate your help!
I would recommend a single pole three position switch. That would meet your requirements better.
Maximum current will be around 3.5-4A and maximum voltage will be around 6VDC.
If this is safety critical, I would not use one switch but two. One to turn on one of the lights and the other to turn on both, you can wire this up in such a way that it would be impossible for this to happen.
give me a second, I will send an updated drawing...
In the actual product, the two primary components are a laser line module and a Raspberry Pi, the LEDs are just there as indicator lights to show when each component is on, and I was using them to test the switch function. My supervisor wants to have one function where only the laser is on and another where the laser and RPi are on. I originally had 2 power switches but I was told that it looks too much like a prototype and was asked to remove one of them. We do have other built-in safety switches (a lid interlock switch and a keylock switch) for the laser since it is powerful enough to require federal regulation.
Thank you, however I need to have a single switch to control both of them. I agree that 2 switches would be much simpler, but the guy who signs my paycheck wants the device to only have 1 power switch, so my hands are tied there.
I understand.
This does not seem to solve the issue, but thank you for the suggestion. I think my best bet is to go with a SP3T switch as you suggested before.
I WAS WRONG ON THAT! There is no way to wire up that type of switch to do what you want. Sorry about that.
No worries. Thanks anyway. Do you think a higher quality rocker switch would experience the same problem as the cheap ones I currently have? Going to a rotary selector switch such as that one might be a viable option, but it protrudes farther from the unit and it may not fit with the exterior geometry of the enclosure, which was designed with a low profile rocker switch in mind. I'd rather not redesign the enclosure because of the power switch unless I have no other option.
I think we can find a switch that will not exhibit the problem. Let me snoop around...
Otherwise it will be hit and miss guessing. You want a switch that is guaranteed not to have the problem you are experiencing.
