Laptop Protector

Here the notebook anti theft protector circuit to secure your important netbook / notebook from stealing. Basically, this is a mini security alarm generator. Fixed inside the notebook case, it will definitely sound a noisy alarm when a person attempts to grab the notebook. This very sensitive circuit utilizes a homemade tilt switch to turn on the alarm system through tilting of the laptop computer case. The circuit utilizes readily available...

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220V AC Lamp Touch Dimmer

Here the 220V AC lamp touch dimmer circuit. By only touching this touch dimmer you are able to increase the light intensity of incandescent lamps in three stages. The touch dimmer is designed all around 8-pin CMOS IC TT8486A/TT6061A especially produced for touch dimmer applications. In the beginning, when mains switch is “on”, the lamp is “off”. Now, when you touch the touch plate, the lamp glows dimly. On second touch, the lamp provides medium...

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Simple Traffic Light Controller

Here the simple traffic light controller which is could be used to educate kids rudiments of traffic light guidelines. The circuit utilizes easily available electronic parts. It generally consists of rectifier diodes (1N4001), a 5V regulator 7805, two timers circuit using IC 555, two relays (5V, single-changeover), three 15W, 230V light bulbs and also several discrete parts. Mains electrical power is stepped down by transformer X1 to provide...

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Simple Symmetrical Power supply +25v -25v

This symmetrical unregulated power supply is used to feed the audio amplifier based on LM1875 amplifier module National Semiconductor. With symmetrical 30V DC source the amplifier capable of delivering up to 30W of power using 8 ohm load. The diagram above shows how the DC +25 V and-25V DC can be obtained. Ready to provide power to two stereo amplifiers, one 80VA transformer with 240V input and 36V output, with the center tap is used. The output...

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Touch switch electronic circuit based on a Schmitt trigger

This touch switch electronic circuit is based on a Schmitt trigger with latching, built IC1a, IC1b and R3. IC1b's output signal comes back to IC1a input through R3, resulting in maintaining stable condition of both gates. While the circuit is at rest, the anode of D1 is at "0" and the cathode of D2 is at level "1" retain their status. When contact is shorted by finger touch, the voltage drop across R8 increases. This increase is translated...

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100W inverter 12V to 220V

To lower or raise any specific voltage is better adapted from a transformer, but this component does not operate in direct current, which is available in battery or vehicle. Therefore we must put an oscillator that generates an alternative current. The Integrated circuit (CD4047) is an oscillator that has the output inversely to one another. This means that while if one is high, other states are low and vice versa. The signals are too weak...

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Surround Sound Decoder

Parts List: R1-2-7-8-12-13-18-19-20=47Kohm R3-4-5-6-21-22-34-35=10Kohm R9-10-11-14-15-16-17=15Kohm R=23-24-25-33-36=100ohm R26-27-28-31-32=100Kohm R29-30=5.6Kohm C1-8=47uF 25V C2-7-9-14-23=47nF 100V C3-6=1uF 100V C4-5-10=33pF 100V C11-12-15=10uF 25V C13=82nF C16=18pF 100V C17=100pF mini adjustable capacitor C18=2.2nF C19=4.7uF 25V C20=100nF 100V C21=10nF C22=180pF C24=150nF RV1-RV2=2X10Kohm  Log. pot. RV3-4=10K Log pot. D1=1N4148 IC1-6=TL072 IC2-3=TL074 IC4=MN3101 IC5=MN3004 JI…..J6=RCA...

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Power Amplifier 14W Class A

This class A amplifier circuit requires a preamp as it hasn’t got much gain. It requires big heat sinks and a large transformer and a great power supply and careful wiring, but in the end it is extremely simple and it sounds very good. The zener diode rejects any ripple coming from the power supply, But you still only want a ripple of 10mV max. The ripple reaching the input is amplified, so the zener gets rid of that, but whatever ripple...

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