Free electronic circuit design and schematic diagram
This circuit is used to prevent the damaging effects of a reversed-polarity battery or short-circuit load. It is used to replace the simple fuse that usually used for overcurrent protection because the fuse has long reaction time and high resistance. This circuit consist of dual comparator, a combination of current amplifier, and external CMOS. A logic-controlled switch can provide low […]
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Twisted-pair wiring is a wiring technique that usually used for in-building data communication. Compared to conventional coaxial-cable, this technique offers substantial cost saving, for video transmission on the same medium. A differential driver is used to launching a baseband camera signal to twisted pair. Twisted pair exhibits a roll-off characteristic that need equalization to correct for. The differential driver and […]
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This is an audio amplifier circuit which has power of 18W. It is very simple but it has a high quality. This circuit does not require pre amplifier. It can be directly connected to tuners, tape recorders, and CD players. It produces 18 Watt RMS into 8 Ohm (1KHz sine wave) output.this circuit has a good sensitivity, for 18W output […]
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This circuit is made to be an alarm, both for home and handbags. If it is installed for home it will placed on door or windows, and if it is installed for bags or handbags it will placed in the bag. This circuit consists of a small magnet and a reed switch. If the magnet looses its contact with the […]
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This circuit is a simple buzzer circuit and it called novel buzzer. It only uses a relay in series with a small audio transformer and speaker. The relay will operate via the transformer primary and closed relay contact, when the switch is pressed. The normally closed contact will open as soon as the relay operates, removing power from the relay, […]
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This circuit included in the category astable multivibrator. This circuit is used to test N-Mosfets (the power kind e.g irf830), whether it works or not. If it is not working, the LED will not flash. If Mosfet is working it will operate in the astable multivibrator circuit causing the Led to flash. Here is the circuit diagram: To make the […]
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Electroscope is a device that is used to detect electrostatic charges. Operation: To reduce AC noise this circuit uses C1, but it will lower the sensitivity a bit. As a voltage divider we use the MPF102 and R1. The divider’s output will be about 4.5V diving a half-scale reading on M1, a 200-uA meter, when the FET’s gate is earth […]
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