IR Remote Control Tester: Circuit Diagram & Intensity Measurement

Circuit diagram

Notes:

During the development of my IR Extender Circuit, it was necessary to determine the comparative strengths of various infrared light sources. This circuit represents the outcome of extensive research. An SFH2030 photodiode was utilized as the infrared sensor. Furthermore, a MOSFET opamp, the CA3140, was incorporated into the differential configuration to boost the current pulses originating from the photodiode. LED1 serves as a standard coloured LED, illuminating when infrared radiation is detected. The output of the opamp, specifically pin 6, may be connected to a multimeter configured to measure DC voltage. Comparisons of infrared remote control power levels can be conducted based on the multimeter reading; a higher reading indicates a more potent infrared light. Different remote controls were directed at the sensor from approximately one meter away during experimentation. Approximately one volt is produced at the output for each microamp of current flowing through the photodiode. It is important to note that a 741 or LF351 will not function correctly in this circuit. Despite employing a 12-volt power supply, a 9-volt battery can also be used successfully here.

Integrated Circuits - CA3140

The CA3140 is a versatile operational amplifier commonly employed in analog circuit design. This integrated circuit offers high gain and excellent performance characteristics, making it suitable for a variety of applications, including amplification, filtering, and signal conditioning. Its differential input architecture allows for precise measurement and amplification of subtle current variations originating from the photodiode, enhancing the accuracy of the IR Extender Circuit. The CA3140 is a three-terminal integrated circuit, commonly known as an op-amp, which is widely utilized for amplifying weak electrical signals. It’s a fundamental building block in many electronic systems and is renowned for its stability and accuracy.