When the remote control is broken. We cannot use it. First, we should check the battery. If the battery is good. The remote circuit may be a problem. We cannot check it with a normal tool, multimeter. This simple remote control tester circuit may help you. It can read an infrared light of remote control.
How it works
In this Simple remote control tester circuit. So we use the phototransistor as the light receiver from the remote control.
If it is good. The phototransistor-Q1 will get the infrared light, the current flows through it to the base of Q2(PNP transistor BC558).
It switches on. the current from the ground can flow through R1 to Q1. The Q1(PNP transistor) also gets a bias current. It is working. So LED1 lights up. Because a high current passes it.
The variable resistor VR1 is used to adjust the sensitivity of the circuit.
How to build this projects
If you want to make this projects, First, you may test them on breadboard. So easy to make.
When you like it. You can assemble them into Universal Board as Figure 2 —the components layout—.
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