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This 1.5 volt led fasher runs more than a year on a single 'd" cell and alternately flashes 2 LEDs at about a 1 second rate. The circuit employs a 74HC14 CMOS hex inverter that will operate at very low voltages (less than 1 volt). One section is used as a squarewave oscillator (pins 1 and 2), while the others are wired to produce a short 10mS pulse on alternate edges of the square wave so the LEDs will alternate back and forth. The output sections each use a capacitor charge pump to increase the voltage for the LEDs.  The circuit draws an average current of 800uA from the 'D' battery and the LED peak current is about 40mA with a fresh battery and drops to about 10mA as the battery voltage falls to 1.1 volts. The capacity of a alkaline 'D' cell is about 12 amp hours with a cutoff voltage of 1.1 so the circuit should run about 12/.0008 = 15000 hours or maybe 625 days, but I haven't verified that yet. The idea for this circuit came from a single 1.5 volt LED f...

This is a Bar Display With Alarm Flasher Schematic Project. Hello Freinds ! Here designed SIMPLE BAR DISPLAY WITH ALARM FLASHER . Schematic: Return to Display Circuits. By using two switching transistors and two LEDs, this circuit can distinguish low-level ac and dc signals. If the red LED illuminates, the signal is positive dc. If the yellow LED lights, the signal is negative dc. If the signal is ac, both LEDs will light. Bar Display With Alarm Flasher Circuit Schematic

Project image : LED Flasher Project Image A flashing LED based on a 555 is not likely to win the first prize for originality, but such a circuit continues to be useful for all kinds of applications. The thing that makes this version special is the very low current consumption, because the LED flashes only very briefly each time (duty-cycle of only 10%) and because it was specifically designed to serve as a (fake) alarm indicator in a car. The circuit has been configured such that the flashing only starts when the ignition is switched off. Circuit diagram :  LED Flasher Circuit Diagram The latter could have been achieved in the usual way with the aid of two resistors and a transistor connected to the reset line. But by using a clever trick instead, this has become even simpler. The +12 V connection from ‘behind’ the ignition key is connected to the threshold input via diode D3. The astable multi-vibrator is held in the inactive state whenever this point is at +12 V. Only when the i...

These circuits only flash one or two LEDs. This is opposed to the light chaser circuits that can flash four or more. Of course, the simplest LED flasher is simply to use a flashing LED . The problem with that approach is you have no control over the flash rate, but it does have its use for eye catching displays for selling stuff. The circuits below give you that control, plus they can flash two LEDs alternately. There are many possible applications for the circuits below, especially for kids, who love flashing lights. Here's some possible uses. Railroad crossing signal for model railroads. Safety blinkers for bicycles, etc. Fun stuff for Halloween, like making those plastic Jack-O-lanterns blink (try using ultraviolet LEDs here). Christmas decorations. Blinkers to locate items in the dark. Transistor LED flasher This circuit has a lot going for it. For one thing, it only consists of two transistors , two capacitors and four resistors . That also means it consumes very little ...

It is a low-cost circuit diagram project for Low Frequency Oscillator-Flasher Circuit. Electrolytic capacitors are unnecessary to generate a 1 cps frequency. As an scs triggers on, the 0.2 µ¥ commutating capacitor turns off the other one and charges its gate capacitor to a negative potential. Low-Cost and Low Frequency Oscillator-Flasher Circuit Diagram: The gate capacitor charges towards 24 volts through 20 retriggering its scs. Battery power is delivered to the load with 88% efficiency.  The 20 resistors can be varied to change prf or duty factor.

This is a flasher that uses 4 high brightness LEDs that can be used in Automotive , Motorcycle or bicycle . It uses the IC 555 which is a monostable to adjust the flasher you can use the RV1 , which can be a potentiometer or trim pot 100k . If built in SMD it fits within the own flashlight .  LED Flasher for Cars and Motorcycles Circuit Diagram