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Showing posts from December, 2016

Reset Protection For Computers

It is very simple and low-cost Electronic circuit diagram for Reset Protection For Computers. This protection circuit is inserted between the reset switch and the motherboard. The earth connection of the computer must be linked to terminal of the protection circuit. The protection circuit can draw its power from the computer supply. When the circuit has been fitted, operation of the reset switch will not immediately restart the computer. Instead, a buzzer will sound to alert you to the reset operation. Reset Protection For Computers Circuit Diagram : The buzzer is actuated for 4 s by monostable IC1A, which is triggered by the reset switch. During these 4 s, the output, pin 5, of IC1A ensures that the reset function, pin 10, of IC1B is disabled. When the reset switch is operated again, monostable IC IB will be triggered and this starts the reset procedure. Transistor T2 is then switched on for 0.5 s and the buzzer is deactuated via Rll and D4. The circuit around T1 and N4 ensures that I...

Splitter and Amplifier Video Circuit Diagram

This is the video amplifier circuit with splitter, it is designed to amplify the video signal, compensating for the loss of signal because this signal will then be split up to three outputs. The output signals may be used in television monitors, recording at the same time several DVDs, etc. .. The advantage of this circuit is that it is quite cheap, easy to build and the results are very good. Splitter and Amplifier Video Circuit Diagram The video amplifier circuit has a maximum gain ratio of only 4 times the impedance is 75 ohms on the input and output, and wide bandwidth of this circuit is 5 Mhz adjust VR1 1. Adjusting VR1 until the voltage at the base of Q1 is equal to one volt. And is the voltage drop across R7. (No input signal). Approximately 0.75 volts. 2. Adjust VR1 in the middle Enter the input signal is 1 Vp-p, then adjust VR2 to have the lowest rate of increase. Then turn on the TV or monitor to the output and then adjust VR1 until the test signal to be applied without disto...