This is a simple how-to guide on making a cheap remote/wireless ignition for a spud gun or other application. It uses a doorbell circuit to transmit an RF signal to activate a relay that completes a 9V stun gun circuit, turning it on. Can be made for less than $20.
Components (you don't have to use the exact model part as I have, any with the same specs will do):
1x Arlec 149 door chime (any wireless door chime will do)
1x 100uF 10V capacitor (10ML100MEFC6.3X5)
1x 1A 200V standard diode (1N4003)
2x SPDT on/off toggle switch
1x key on/off switch
1x momentary button
1x project box
1x 3V DPDT relay (IM01TS)
1x 100kV stungun
Box of jewellers screwdrivers (not required but helps when fiddling with small parts)
Heat shrink (not required but is recommended)
Credit for the two circuitry diagrams and alternative relay wiring graphic, Spudfiles member: dewey-1
Step 1: Modifying the Door Chime
Determine the voltage applied to the circuitry of your door chime receiver, some are 3V some may be higher like 5V. Doesn't matter which voltage it is, any will do.
First, you need to cut the two wires that are going to the speaker. Once that is done, determine which wire is positive and which is negative by connecting them to an LED, voltmeter or other electrical component that can tell you the polarity. Another way is by finding the transistor near one of the wire terminals, it seems that the transistor is generally connected to the negative wire.
Next, we need to determine which relay we need. The relay is an electrically operated switch, when a low powered signal is sent to a relay, it closes a switch and allows the signal to carry on to the rest of the circuit. In this case, the relay will be completing the circuit of a stungun. When you attach a 9V to your stungun circuit, it should spark continuously but if we put a relay between the 9V positive terminal and the stungun positive terminal, the stungun can't spark until the relay has been activated.
If your door chime circuit is also 3V, find a 3V relay similar to the one I used (model number is on the components list).