Free electronic circuit design and schematic diagram
This linear voltage regulator circuit provides battery voltage regulation from battery source to power micro controller system. The output can be selected by choosing the right resistor value in the feedback path. Many today’s micro controllers are featured with power down or power saving mode, and this circuit accommodates this feature by providing low power mode control on its input. […]
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The requirement of a continuity tester is that its current should be small enough to not destroy the tested circuit. This simple circuit inject not more than 0.6 mA current into the tested path in the tested circuit. The schematic diagram describes all the circuitry of the circuit. This circuit is used to test if two point is electrically connected […]
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High voltage applications can be found in various fields, such as ignition in internal combustion engine, gas igniter, cathode ray tube excitation, ionizer for dust odor catcher for air sanitary, ionic propulsion or many other things. The schematic diagram presented here shows a circuit of high voltage generator that can be used for various purposes. This circuit uses a 4049 […]
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For critical operation, the power loss can be unacceptable. It might be costly if a financial data is lost from the memory in the middle of point of sale transaction, or even it can be deadly if some life support devices fails during critical surgery. The schematic diagram presented here is a battery backup regulator circuit, useful for memory or […]
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A compressor circuit shown in the schematic diagram below can produce consistent output of 1.4V P-P over entire 60dB range that is very useful for audio level/volume stabilization. As the main components, this circuit uses a 741 opamp and JFET. With input range of 20mV to 2oV, this circuit has delay time of 0.4s (decay time) and response time of […]
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The voltmeter shown in the schematic diagram below has very high impedance. The range selector uses conventional voltage divider resistors, but since the following pre amplifier uses JFET, the divider can be designed using very high resistance series resistors. This DC voltmeter circuit also featured with low drift. This circuit uses a pair JFETs, which is configured in a balanced-bridge […]
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When we modulate a carrier signal with amplitude modulation, there will be four frequency components as the result. The first is the modulating signal itself, the second is the frequency carrier, the the latest two are the difference and the sum of the carrier and the modulating signal. The spectrum of these frequencies can be seen using frequency analyzer. In […]
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