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3v Low Battery
Voltage Flasher
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 voltage 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...
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3 Volt Low Battery Voltage Flasher
This circuit is designed to monitor two alkaline cells (3v) that form the battery
often used in portable electronic equipment. It use an inexpensive IC from
Panasonic that is connected to an efficient LED flashing circuit. When the
battery voltage drops below a certain point the circuit flashes the LED. In
the off state the circuit draws only 1uA, while in the active flashing state it
draws 20uA. Published in EDN, Jan 2, 1997
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9v POWERED XENON PHOTOFLASH Controller
This 9v battery powered circuit is designed for remote control flash needs. A
charge control circuit turns off the high voltage generator when the photoflash
capacitor is fully charged. A neon lamp is included to indicate when the
system is ready to flash.
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Battery Free
LED Flasher
LED flashers have been used for a wide variety of applications. Some flasher
units have been used in food and hardware stores, to draw attention to sale items
and are often attached to boxes which dispense product discount coupons. Typically,
as the illustration below depicts, these simple units have a red LED, on each side
of the housing. Inside, is a battery and flasher circuit....
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Fake Car Alarm Light
Whenever the car’s ignition is turned off, this circuit activates a flashing LED,
which can be positioned to appear as an active alarm system....
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FLASHING LED ADVERTISING BADGE #1
I have seen numerous flashing light badges at trade shows and conventions. They are
often handed out as gifts to promote some business. The devices often use
inefficient circuits, which cause the battery power source to be quickly depleted.
My circuit is simple but efficient enough to provide months of continuous LED
flashing. It also has a tiny push-button switch to turn on and off the light
flashing, extending battery power.
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- High Intensity
Line Powered LED Flasher
There are times when you would like to generate an intensely bright flash of light
using electrical power from the AC line. The circuit below can drive a one to
three watt power LED with about 350ma of peak current. Since the circuit
drives the LED with a constant current, any LED color can be used. I have also
shown how you could use an array of 7 LEDs, wired in parallel. This array may
not produce as much light as the single power LED but the array would be cheaper to
build. ....
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