Fading Red Eye Circuit

This circuit is utilized to gradually light up and blur a couple of red LEDs (light radiating diodes). The fading LEDs could be introduced as “eyes” in a little pumpkin or skull as a Halloween fascination, then again mounted in a Christmas tree adornment.   On the other hand, they may be utilized as an […]

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1.5V LED Flasher Circuit

The LED flasher circuits beneath work on a solitary 1.5 volt battery. The upper circuit, shows utilizing a 100uF capacitor to twofold the battery voltage to get 3 volts for the LED. Two segments of a 74HC04 hex inverter are utilized as a squarewave oscillator that builds up the glimmer rate while a third segment […]

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40 LED Bicycle Light Circuit

A simple bicycle flashing light circuit using LED arrays is explained below. Designed by me. The 555 circuit design below is a blinking bike light, activated with 4 C,D or AA cells (6 volts). A couple of arrays of 20 LEDs is assigned to alternately blink at around 4.7 flashes per second by employing RC […]

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Light Operated Relay Circuit

In this post you will learn about a very simple light activated relay circuit in which a relay is toggled On/OFF in response to the light or darkness over a photo sensitive device, the circuit utilizes only a Darlington transistor for activating the relay The light sensitive relay circuit presented here has been configured such […]

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Marker Generator Circuit

The marker generator circuit explained here is a constant- frequencyoscillator driving into a CMOS divider chain. Switchable out- puts from the divider chain are selected to drive a pulse generator. The oscillator is C1a in which R1 biases the IC into linear operation. The crystal determines the basic frequency of operation at 4 MHz in […]

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Theremin Circuit

This is the only musical instrument known to the writer that is played without being touched! The Theremin is named after Professor Theremin who, in 1928, amazed New York audiences when he demonstrated his ability “to obtain music from the ether”. The instrument has two rods protruding from its housing, each one forming one ‘plate’ […]

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Precision Rectifier Circuit

The post explains a simple precision rectifier circuit using just two opamps. This precision rectifier operates from an asymmetrical supply, handles input signals up to 3 Vpp and has a frequency range that extends from DC to about 2 kHz. Its amplification is unity, and depends mainly on the ratio R4/R3. Opamp A1 is connected […]

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Sine Wave Oscillator Circuit

To maintain oscillation the op. amp. must have a gain equal or exceeding this attentuation which is in fact x3. The desired gain is obtained by selecting the ratio of feedback resistance to input resistance of the inverting input (RV2 + R3)/R2. lf the overall gain, including feedback, exceeds unity the circuit will produce sine […]

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Simple Metal Detector Circuit

In this post we will how to make a simple metal detector circuit at home This metal detector is a low sensitive type  can be powered by a battery 3 to 15V, and may be constructed employing four exclusive OR gates from a CMOS integrated circuit 4030. The gates have been connected as two oscillators […]

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