Police Style Strobe Light Circuit.
This circuit shows the familiar lights which are used on police cars. It uses a 555 timer as a clock for the 4017B decade counter, two transistors and twelve LEDs
Doorbell for Deaf People.
When a deaf person is alone in a house, it would be very difficult to realize that someone is knocking on the door without any visual warning signal.
The main component for the Doorbell for the deaf circuit is the CMOS 4001 integrated circuit, which has four two input NOR gates
Light-Emitting diode connected to 120/240 VAC Caution: This circuit is connected directly to the power line (120 / 240 volts AC), so you must take special care to test it. This circuit shows one or two LEDs (Light-Emitting Diode) directly connected to the outlet (120 VAC or 240 VAC). The reduction of the AC input voltage to […]
LED – Light-emitting diode Light-emitting diode (LED) is a special type of diode, that emits light when it is forward biased. There are LEDs of various colors. LED colors depend on the material with which they were built. There are red, green, yellow, amber, infrared, etc. If a current flows through a semiconductor diode, there are electrons and holes […]
What is a Zener diode? The Zener diode is a special type of diode that allows the flow of the current to run on the opposite direction of the arrow of the diode. This diode does not conduct until the applied voltage reaches or is greater of the breakdown voltage. This is the “zener voltage”. Note: The zener diode behaves like a common semiconductor […]