Electronics

LED Torch with adjustable brightness

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The Led torch with adjustable brightness circuit uses LM3914 as the basis of a 10 step variable brightness current-regulated white LED . This circuit has only four components in the control and regulation circuit: R1,R2, VR1 and LM3914. Part List 1. IC – LM3914 2. LED1-10 – 10 white led 3. R1 – 620 ohm 4. […]

Electronics

Mains Powered LED Lights

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All mains powered LED circuits work with 240 volt AC current. Mains powered LED – Single LED The power diode in the first diagram is designed to discharge the 220n during one half of the cycle so that the capacitor will charge during the other half-cycle and deliver energy to the LED. The 1k resistor […]

Electronics

LED Flasher using NE555

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LED Flasher circuit using NE555 timer IC   R1, R2, C1 and the supply voltage determine the flash rate. For a variable flash rate, replace R1 with a 1 MΩ pot in series with a 22k resistor. The purpose of R3 and R4 is to limit current through the LEDs to the maximum they can handle […]

Electronics

USB Reading Lamp

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USB reading lamp is powered using USB port. The USB port provide 5 v and 100mA which is sufficient for this circuit. Cut the one end of the USB cable and use RED(pin1) and Black(pin4) for 5v positive and negative respectively.   Parts c1,c2 – 100 mF 25 v Zener diode – 4.7v 400m R1- […]

Electronics

10 Stage LED Sequencer

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10 Stage LED Sequencer Components   IC1- CD4017 IC2- NE555 C1 – 1μ C2- 0.01 μ R1 – 470 Ω R2 – 100 KΩ R3- 100 Ω LED1-10 – RED LED 9volt DC power supply.                               For power supply you can use 9 volt […]

Electronics

LED Basics

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Today LED has become an integral part of consumer electronics. LED TV, LED Display, LED Lights and so on. These are becoming very popular because of there low power consumption. What is LED? LED stands for Light emitting diode. A light emitting diode is essentially a PN junction semiconductor diode that emits a monochromatic(single) colour […]