Miscellaneous IR schematics

Men in particular enjoy the convenience of television remote controls – often to the annoyance of their female partners. Men apparently want to know what they’re missing when the TV is tuned to a particular program, so they like to keep zapping to other channels. With the remote control in their hands, they feel like they are the lord and master of the TV set. They are thus completely at a loss if the remote control doesn’t work properly. There are many reasons why a remote control unit can malfunction, such as defective IR receiver in the TV set, a defect in the remote control, or empty batteries. Here a tester that can determine whether the remote control unit still emits an IR signal can come in handy. If you want to keep the IR reins firmly in hand, you can build your own IR detector.... [read more]

The IR detector (IC3) controls an LM 7555 CMOS timer (IC2) which operates in mono stable mode. When the beam is broken, IC2 is triggered and its pin 3 output goes high for about half a second. This extinguishes LED1 and turns on transistor Q1 to drive a 5V low-power relay.... [read more]

Using this circuit, audio musical notes can be generated and heard up to a distance of 10 metres. The circuit can be divided into two parts: IR music transmitter and receiver. The IR music transmitter works off a 9V battery, while the IR music receiver works off regulated 9V to 12V. First diagram shows the circuit of the IR music transmitter. It uses popular melody generator IC UM66 (IC1) that can continuously generate musical tones.... [read more]

Many households are still graced by tube-type television sets. If you want to connect one of these large tellies to your stereo system to improve the sound quality, this is usually not a problem because there are plenty of SCART to Cinch adapters available in accessory shops. However, with some sets your pleasure is spoiled by the fact that the audio outputs of the SCART connector are not muted during channel switching.... [read more]

Here is a simple tester for checking the basic operations of an infrared remote control unit. It is low-cost and easy to construct. The tester is built around infrared receiver module TSOP1738. Operation of the remote control is acknowledged by a tone from the buzzer. The circuit is sensitive and has a range of approximately five meters. The integrated IR receiver detects, amplifies and demodulates IR signals from the remote control unit. The piezo buzzer connected at its output sounds to indicate the presence of signal from the remote control unit.... [read more]

This circuit is useful in liquids level or proximity detection. It operates detecting the distance from the target by reflection of an infra-red beam.... [read more]