Tag Archives: circuit

Moduler Preamplifier Circuit Diagram

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High Quality, Discrete Components Design, Input and Tone Control Modules To complement the 60 Watt MosFet Audio Amplifier a High Quality Preamplifier design was necessary. A discrete components topology, using + and – 24V supply rails was chosen, keeping the transistor count to the minimum, but still allowing low noise,… Read more »

5V Regulated Power Supply Circuit Diagram

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Simple 5V power supply for digital circuits This circuit is a small +5V power supply, which is useful when experimenting with digital electronics. Small inexpensive wall tranformers with variable output voltage are available from any electronics shop and supermarket. Those transformers are easily available, but usually their voltage regulation is… Read more »

Fully Adjustable Power Supply

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Based on a National Semiconductor application note, this circuit uses an LM317 3-terminal regulator (REG1), chosen because of its built-in over-current and over-temperature protection. Its output is boosted up to just over 5A by the MJ2955 transistor (Q1). The output voltage is varied by adjusting the voltage on REG1’s ADJ… Read more »

Bass Booster Circuit

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Increase the bass output of your present instrument at modest cost! Bass Boost is today’s sound… whether it’s the driving, gut-vibration pulsation of disco, or the solid bass line of soft, hard, or laid-back rock. One way to get the modern bass-boost sound without running out and buying an all-new… Read more »

Power Buzzer

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How often on average do you have to call members of your family each day to tell them that dinner is ready, it’s time to leave, and the like? The person you want is usually in a different room, such as the hobby room or bedroom. A powerful buzzer in… Read more »

Hearing Aid

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Portable and easy to built, Uses 1×3v battery Commercially available hearing aids are quite costly. Here is an inexpensive hearing aid circuit that uses just four transistors and a few passive components. Circuit diagram: Hearing Aid Circuit Diagram Parts R1 = 2.2K R2 = 680K R3 = 3.3k R4 =… Read more »

USB Operated Home Appliances

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When turning a computer on and off, various peripherals (such as printers, screen, scanner, etc.) often have to be turned on and off as well. By using the 5-V supply voltage from the USB interface on the PC, all these peripherals can easily be switched on and off at the… Read more »

Cash Box Guard

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Most thefts happen after midnight when people enter the second phase of sleep called ‘paradoxical sleep.’ Here is a smart security circuit for your cash box that thwarts the theft attempt by activating an emergency beeper. The circuit can also be used to trigger any external burglar alarm unit. The… Read more »