Against all odds, my idea for a simple full auto recoil solenoid circuit actually works...
My aim was to achieve full auto light gun recoil from a cheap solenoid using only a micro-switch (trigger) and a power supply. No 555 timers or other parts I don't understand how to use. No programing a Raspberry PI etc and no mame or Windows software issues to deal with.
Check out my proof of concept video:
https://m.youtube.com/watch?feature=youtu.be&v=NNToH3yW60YObviously, it's very crude at this stage (as I didn't really expect it to work). I have to refine the design to ensure the electrical contacts connect consistently and maybe make it safer (those sparks can't be good...).
The basic idea is that the micro-switch connects the solenoid to the power supply which makes the solenoid engage (shoot forward) but, when the solenoid cylinder moves forward, it breaks the circuit. There are copper contacts on the end of the solenoid cylinder. When the spring returns the solenoid back to it's resting position, the copper contacts connect to the power supply again and then the cycle repeats until you take your finger off the trigger.
If you just press the trigger once and release, the solenoid only engages once so there is no need for a seperate circuit or a switch to go from semi to full auto which further adds to the simplicity of the design. I like simplicity as this is not my area of expertise.
The solenoid in the video is a 12v long throw one bought off eBay for around $10. While I bought it for a different project, it actually has two properties that make it great for a light gun. First, it's designed to run on 12v instead of 24v or 36v. This means you get more force with a smaller PSU. The power in the video comes from a small 12v battery (from my hand drill) and it already puts out more force than I need. With a proper wired 12v PSU, it will kick ass. Conversely, the Aimtrak recoil solenoid at 24v is more of a wet fart than a full auto thump.
This solenoid has a 35mm throw - far longer than any other I have seen. That's about how much travel you would expect from the bolt on a real gun (I bought it to cock my PCP air rifle). So, it will look awesome if I connect it to a charging handle to create some visible motion while in use (like the Namco arcade guns).
Obviously, this will be of no interest to some of the very talented people here with tons of electrical knowledge but I thought it worth sharing for others like me who belong on the electronics special bus. But, if any of those talented electricians here have any ideas on how I can make this design safer with less sparks, I would be very greatful. I don't like visible sparks, burning smells or electric shocks if any kind!