Here is a simple tester to test the IR Sensor TSOP 1738. It is a highly sensitive device that damage easily if its input voltage rises above 5V. This Tester can be used to test TSOP 1738 before using in a circuit. It confirms the condition of the Sensor, whether it is functioning properly or not. It can also be used to check the IR Sensors kept in your junk box so that you can keep only the good one for use.
We construct different types of Infrared Receiver LED ( Rx) or IR Sensor ( TSOP 1738 ) based circuits. To test, the working of the circuit we have to use an IR Transmitter. Usually we use IC 555 based IR transmitter for this. But the frequency of the IR from the Transmitter should match with that of the Sensor, otherwise the circuit will not respond. Here is a simple solution to test the IR based circuits. Simply Hack a Mini Remote obtained along with low cost FM radio, Toys etc. You have such Remotes in your Junk box. Let us Hack one such Remote to make a Tester.
A simple circuit to test the TV remote whether it is working or not. TV remote uses Infrared LED to emit pulsed IR rays which are invisible to human eye. So it is difficult to confirm the working of IR Led of remote. This Remote Tester blinks an LED when it receives IR rays from the TV remote.
TSOP 1738 is the Infrared receiver Module widely used in remote control applications including TV. It is a versatile sensor that receives the coded Infrared pulses from the transmitter and directs the functions of the device. TSOP 1738 sensor is designed to receive IR rays pulsating in the 38 KHz and hence the number 1738. It has a circutry inside a black coloured filter case . The black coloured filter case prevents the effect of sunlight and other lights on the Photodiode present inside. There is a PIN Photodide inside the module which is the receiver of the Infrared rays from the transmitter. In addition to the Photodiode, there are signal amplifier, AGC ( Automatic Gain Control), output driver etc inside the module.
Most of the consumer electronic devices use Infrared remote control for easy operation. The Carrier frequency of such remote control may be 36 kHz or 38 kHz. The Control codes are sent to the receiver of the device in Serial Format. This format is Modulated to the carrier frequency by the On / Off method. In the Remote, the IR signals are generated using an IR LED which emits Modulated IR rays. This part explains the details of IR transmission protocol and the design of IR Transmitter.
Photo sensors are used to activate / deactivate electronic circuits. The most common Photo sensors used are IR sensor modules . These devices are designed to receive Pulsed Infrared rays from the IR diode from remote handset. Photo modules are used in TV, CD player, FM receivers etc to control the functions. By pressing each button of the remote, it is possible to emit IR of a particular frequency and the Photo module senses these pulsed IR rays to change the activity of the device. TSOP 17… Series Photomodules are excellent Infrared sensors for remote control applications. These IR sensors are designed for improved shielding against electrical field disturbances.