Free Simple Circuit Diagram
This schematic diagram shows an automatic headlight dimmer circuit for your car’s headlight, keep you safe in the dark with maximum bright for farthest visibility, but will automatically switch from high to low beam when traffic approach to save others sight. With Q1 in moderate darkness the variable resistor must be adjusted to generate no base current through Q2. This […]
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This AM radio circuit is a low power transmitter working on broadcast band. The simplicity is implemented using a single-transistor amplifier stage, and for the stability a crystal is used to excite the 670Hz oscillation. The output power of this AM transmitter circuit is 400 micro watts for antenna. L1 and L3 is 40-300 uH ferrite core antenna. Here is […]
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A pair of cross-coupled SCRs can be used to build a first-response monitor circuit, as shown in the schematic diagram below. First-response circuit is popular in quiz application where the first contestant who press the button will prevent the other activate the button/alarm. The purpose of this circuit in quiz application is to ease the identification of the first one […]
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A normal 9V battery would be considered as dead battery when the voltage falls below 7 Volts. With this switching regulator, a lifetime of a 9V battery will be extended by boosting the voltage if the battery voltage falls under 7.5V. This circuit will maintain the voltage at 7V until the battery voltage falls down to 2.2 volt, a point […]
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