Hi. Is it possible to replace this DPDT switch with something electronically switched by a micro-controller? Maybe a ssr or logic level mosfet? Could someone help with the circuit details if this is possible? Any advice would be appreciated. Thanks!
Here is some functional info about the circuit : That section after the transformer with all the diodes and caps is just a rectifier area. The DPDT switch turns on the solenoid. That relay in the bottom right corner turns off K9 after a delay. This circuit gives the solenoid more power in the beginning to pull on and then less to hold it on. The gray oval components are just spark suppressors for switching large dc.
What voltages & currents are being switched?
A relay can handle a lot of current/voltage pretty easily, just need a transistor and a diode for driving its coil from Arduino.
Thanks guys! I think that may work. Just get another relay and switch it with the Arduino and transistor. The DPDT switch was switching around 24V and not more than 1 amp.
Maybe another D9 part like in the circuit. I think point 13 could be used for the Arduino controlled transistor too?
You could replace the switch with several transistors/MOSFETs, but a DPDT relay is perhaps a simpler
solution - you just need one with suitably rated contacts, reuse the snubber networks, and have one
transistor/diode to drive the relay winding.
I'm looking at these Omron MY Miniature Power Relays. They look very similar to what the original circuit uses. The MY2 specs look about right. I would want a 24V DC coil, because of the original control circuit. The rated inductive load of 2 A @ 24V looks ok for the contacts. The most I will be switching is about 1 A @ 24V through the solenoid. Double seems like a good safety margin. Do you agree with this relay choice?
Final issue is mounting. I was just using proto solder boards. It doesn't look like these relays will fit? Any ideas on what to solder these guys to?
these boards look great. they are tiny, designed for micro-controllers, and mountable. having a hard time finding DPDT though. let me know if u see any.
