Very Simple Light Meter

Very simple light meter can be constructed using LDR (light dependent resistor)  wired in series with a battery, variable resistor, and  ampere meter. Here is the schematic diagram of the circuit: The ampere meter is a 100 uA analog meter. Don’t expect too much about the linearity, absolutely can’t be compared to standard light intensity meter which measure luminosity in […]

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AC-Powered LED

Usually, LED is powered by DC supply, but this circuit can make the LED can be powered by AC supply. This circuit can be used as power indicator for Water pump. There are two circuit  versions of AC-powered LED presented here. First is circuit for US or Canadian 110-120V 60Hz AC lines and European or Australian 220-230V 50Hz AC lines. […]

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555 Infrared Transmitter-Receiver

Infrared transmitter and receiver circuit shown in the schematic diagram below can be used as remote control. The transmitter is basically an oscillator circuit, and the frequency can be adjusted using R1 potentiometer (or trimmer pot). This oscillation makes sure if the signal can be distinguished from other source by the receiver. The receiver is actually a bandpass filter which […]

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TV Remote Control Jammer

This is a TV Remote Control Jammer circuit.  Remote control use modulated light to combat eer infrared nvironment/background infrared noise. Your room heater, sunlight, incandescent lamp, and many other devices emit infrared. Without modulating the infrared carrier, other source of infrared will block the remote control signal, since the othsources are mostly strong enough. Since the remote control transmit IR […]

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