Introduction: Infrared Remote Control Tester Using TSOP4838

By ElectroMaker

Here's how to build a simple remote control tester circuit. Just follow the steps below and you'll make it under 5 Minutes. If it works then please leave a like on our video and tell us in the comments :)

Step 1: Watch the Video

I Have shown full process on how to make this circuit in my video, So if you wish to watch it then Link is provided below- https://www.youtube.com/watch?v=V76oFH5a9DA

Step 2: Have a Look at the Schematic

Step 3: Buy Some Parts

Parts List-

IC1- LM7805 (not necessary, You can directly use an 6V Battery. But i am using 9V Battery so i need to reduce to the voltage)

IC2- TSOP4838 (Other 38KHz Infrared Receiver Module Can be used like TSOP1738. But be careful about the pinouts otherwise you will toast your IC)

D1- 1N4007 or Any rectifier diode (Not necessary, Just to protect from reverse polarities. I have actually fried 3 Receiver modules due to reverse polarity)

QI- Any generic PNP BJT Like BC557, 2N3906 etc (Ignore the NPN Symbol on the scheme)

LED- 3V LED 20mA (Any colour, Its not a big deal)

R1- 47 Ohms (Use according to your LED)

Power Supply- 9-12V (Don't use a LM7805 For Voltages Below 6V)



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Step 4: Troubleshooting Guide

If Your Circuit Does not work, Try using the guide below and see if it works (If not, Please feel free to ask us in the comment section of our videos)

1. Make sure that your receiver module is okay.

2. The receiver module could be damaged if exposed to high voltages before so buy a new one

3. The pinouts of the TSOP1738 And TSOP4838 Or any others are different so make sure you've got connections with TSOP right

4. Check for short circuits (I Prefer using a multimeter)

5. Make sure that the connections with the transistors are correct

6. Use a PNP Transistor, If you use NPN Then it will not work

7. Observe the polarity of the LED

8. Check your power supply

Step 5: Explaination

Here's a short explaination about our circuit (I Will not go into details but you can find more info at youtube, Google etc) So TSOP4838 is a 38KHz Infrared reciver module, The last Two digits indicate the working frequency (38KHz) So TSOPxx38 can be used. It just needs to be a 38KHz one. If you are wondering why exactly 38Khz one then it's because Most of the reomote controls use a communication via Infrared light which is sent to the the Receiver (It maybe your set top box, DVD Player etc) at a frequency of 38 Kilo Hertz. Now you why so let's move on to other components. So when any button is pressed on the remote control the receiver catches it and outputs 0V (That's why we used a PNP Transistor) And when it outputs 0V The transistor switch closes, The circuit completes and the LED Glows via a 47 Ohm resistor. The led flickers because the infrared light from the remote control is not consistent, Otherwise you could use a normal IR LED To control your appliances. This infrared light is send into short pulses which the DVD Player or anything decodes and turns its output, Every button has different codes, That's why our LED Glows in short pulses. To remove the flickering of the LED, Just put a 10 to 100 micro Farad capacitor parallel to the LED. That way when TSOPxx38 Outputs the LED Glows and capacitor charges as well, And when the output is turned off, The capacitor dumps it energy to the LED and it looks like the LED Is glowing all the time. That's simple right? :)