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Micro Power AM Receiver

Micro Power AM Receiver... [read more]

220 Volts Flashing Lamps

This circuit is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing.... [read more]

Simple Capacitive Touch Sensor

Capacitive touch sensors are based on the electrical capacitance of the human body. When, for example, a finger comes close to the sensor, it creates a capacitance to Earth with a value of 30 to 100 pF. This effect can be used for proximity detection and touch-controlled switching. Capacitive switches have clear advantages compared to other types of touch switches (for example 50 Hz or 60 Hz detection or resistance detection), but are often more complex to implement.... [read more]

Protection For Telephone Line

A long time ago when telephones were so simple almost nothing could go amiss from an electrical point of view, Telecom operators installed surge protection on all telephone lines exposed to storm risks. Paradoxically, now that we are hooking up delicate and expensive equipment such as telephones filled with electronics, fax machines, (A)DSL modems, etc., this protection has disappeared.... [read more]

Amplifier Timer Circuit Schematic

This circuit turns-off an amplifier or any other device when a low level audio signal fed to its input is absent for 15 minutes at least. Pushing P1 the device is switched-on feeding any appliance connected to SK1. Input audio signal is boosted and squared by IC2A & IC2B and monitored by LED D4. When D4 illuminates, albeit for a very short peak, IC3 is reset and restarts its counting.... [read more]

IR Music Transmitter and Reciever

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]