3v low battery voltage flasher


Posted on Feb 7, 2014

Many battery powered devices use two AA alkaline cells. Often you will not know when it is time to replace the batteries until the device powered by them actually stops operating. The hobby circuit below can be connected to a 3v battery, to give you some warning when the battery is nearing its end of life. It will flash a LED when the battery volt


3v low battery voltage flasher
Click here to download the full size of the above Circuit.

age drops to about 2. 4 volts. The electronic circuit draws only 1ua of current in standby mode and jumps to only 20ua when flashing, so it can safely be included without depleting the battery energy. A voltage detector IC from Panasonic (Microchip also makes similar devices) is used to monitor the battery voltage. The device`s open drain output swings low, when the battery voltage is below 2. 4 to 2. 5 volts. This action turns on the two transistor oscillator circuit, which drives the LED with short current pulses lasting only 2ms. I published this Flasher circuit in the January 2 issue of EDN magazine in 1997.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    current mode amp powers 24 ghz
    preamp HF VHF UHF SHF wideband MAR6
    microphone amplifier 20khz 12v
    LM4844 Stereo 1.2W Audio Sub-System With 3D Enhancement
    Simple Infrared Control Extender
    Colorful lights loop circuit
    The Q value of the variable notch filter



    Top