Total Arduino Noob here. I have an interlock kill switch that is connected to a laser, where if the button is not pressed, the laser fires, and when the button is pressed the laser stops firing. The switch is just a push button and it connects to the laser with a 2-pin XLR female output to 2-PIN XLR male input on the laser
I want to automate this process by using an Arduino so I can send signals from my machine to the laser's XLR input. I took apart the kill switch and it's just a GND and PWR wire connected to the push button circuit.
I am using a 5V relay module to serve as the switch. To my understanding, if the interlock button has no power supply, then can I just connect the red wire to the relay's COM pin and connect the black wire to the relay's NO pin and then just hook up the relay module as normal to my Arduino?
I've attached an image of the schematic diagram I've made.
Please let me know if I'm heading in the right direction. Thank y'all so much!
Normally a kill switch or common E Stop (Emergency Stop) consist of a simple latching circuit where pressing a N/O (Normally Open) button will latch the circuit and pressing any of one to several N/C pushbuttons will unlatch or kill the circuit power to whatever is out there. A Google of "latching relay circuits" should get you a dozen examples.
A simple example:
Things work like this. SW1 is a normally closed PB switch. SW2 is a normally open PB switch. Momentary pressing SW2 energizes RY1 coil closing one set of RY1 contacts "latching" the circuit. Other contacts on RY1 not shown, handle the load. Momentary press on SW1 will deenergize RY1 coil and RY1 will drop out.
They do make latching type relays in a variety of flavors so find what works for you and your application. I merely posted an example of one such circuit.
Yes, you can configure a relay circuit to be "latched" by a signal from an Arduino or just about any uC. Again a Google of relay latching circuits should get you a few dozen more examples.
It's good because almost any fault will trip the interlock, including temporary loss of power.
It's especially important to follow best practices when implementing safety features. I worked for a while in industrial controls, and it was considered unacceptable to allow any CPU to implement a kill switch or emergency stop.
