Hi, this is Wayne again with a topic “DIY Hacks and How Tos Remote Kill Switch”.
This week, I’m going to show you how to make a remote kill switch. That will let you remotely turn something on and off. The first thing that you need is a radio transmitter and receiver, I’m using an old pair of walkie talkies start by removing the housing of the receiver. We need to connect to the output of the receiver circuit in this case.
That’S the wires that go to the speaker, so I cut off the speaker and strip the insulation off the end of the wires. I also cut off the call button because that wasn’t going to be used now we need to connect the receiver to a control circuit. The signal from the receiver is a series of pulses, so I used a diode, a capacitor and resistor to help smooth out the signal. An op-amp then compares the signal voltage to a reference voltage, that’s set by a pair of resistors when the signal voltage goes above. The reference voltage, the op-amp activates a relay through a power transistor.
First, I prototype the circuit on a breadboard. I tested it out by connecting an LED to the output of the op-amp, then I soldered all the parts onto a circuit board. In this case, the receiver required a different voltage than the control circuit, so I built a simple voltage regulator for the receiver so that they could both be powered by the same 12-volt battery. I also had to make one modification to the transmitter.
The call button was a momentary switch. I wanted to replace it with a latching switch so that I wouldn’t have to hold down the button to do this. I just disordered the original button and soldered on a sliding switch. Then I cut a slot in the housing and glue the switch in place. Now we’re ready to connect the remote kill switch to the device that we want to turn on and off. I decide to hook it up to my son’s Power Wheels car. This is a high current application, so I used an automotive relay to control it. I cut the wires from the battery and crimped on a pair of connectors that match the tabs on the relay.
Then I attach them to the common terminal and the normally open terminal on the relay to secure everything in place. I taped all the parts to the in side of the battery compartment. Now I can remotely turn the car off if my son starts driving in the wrong direction, thanks for watching and check back next week for more DIY hacks and tattoos. .