Simple IR Remote Control Connect this circuit to any of your home appliances (lamp, fan, radio, etc) to make the appliance turn on/off from a TV, VCD or DVD remote control. The circuit can be activated from up to 10 metres. The 38kHz infrared (IR) rays generated by the remote control are received by IR [...]

Q1 NPN MPS3904 Transistor Q2 PNP MPS2907 Transistor Q3 NPN MPS2222A Transistor Q4 NTE342 (cross reference 2SC1971) L1 & L2 are air-core coils…8mm diameter…3 turn wrap…1 turn tap (L1 is tapped one full turn from the diode side (D1) of the coil…L2 is tapped one full turn from the collector side of the MPS222A transistor) [...]

The Circuit shown can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Frequency range is 88-108 MHz. Max current consumption is 30mA.

A stereo power amp designed for use in portable players and radios. A 3V supply can be used to drive headphones providing 20mW in 32 Ohms per channel, and a 9V supply will provide 1W in 8 Ohm per channel for small loudspeakers.

Download eprom: KOPERNIKUS 21C32

The circuit shown depicts a wide band FM wireless microphone. Its power and range are similar to the commonly known circuits, which use bipolar transistors. The simplicity of the design means it is certain to work first time. One gate circuit of the MOSFET is a self excited RF oscillator, and the other gate circuit [...]

This is a nice 2 Watts FM transmitter. It has a Super-Sensitive pre-amplification with BC109 and BC177 with more than 100% signal modulation. The job finish the 2N2219 by Motorola. For the Coils you should use 1mm wire(enameled), L1= 3 turns – 10mm diameter, L2= 1 turn – 10mm diameter. R9 trimmer controls the modulation [...]

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Most off-the-shelf car battery chargers cannot not be left connected to the battery for long periods of time as over-charging and consequent battery damage will occur. This add-on circuit is placed in series with the battery being charged and is powered by the battery itself. In effect, the circuit uses a high-current Mosfet to control [...]

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