High Voltage 220V AC Lamp Flasher Using 555 IC

Similar with previous high voltage¬† flip-flop circuit, this circuit controls high voltage (powerline) bulbs (220V AC). Instead of using transistors, this circuit uses NE555 integrated circuit, a very popular chip for timer or oscillator application. The required low voltage supply for 555 IC is provided by direct converter, made up by D1, R1, DZ1, and C1. This low voltage is […]

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Classic Two Transistor Alarm

Assemble Alarm Circuit

A very simple alarm circuit can be built using two transistors and several passive components. We don’t know who is the inventor of this circuit, but it usually presented in many old electronics books, so let’s call it “classic”. This simple circuit implement complete function of an alarm, which is nothing more than an oscillator¬† with high enough power to […]

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