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Dave's Flashers & Blinkers Circuits: Page 1, Page 2 |
High Power LED Flasher August 3, 2008
Power LEDs are becoming more popular these days. The DC input power to these devices ranges from 1 watt to 5 watts. Normal LEDs only receive about 0.05 watts. At this higher power, these devices can emit a lot of light. You
can buy them in just about any color in the rainbow but white seems to be the most popular. One application for these devices is a flashing light. If the flash duration and flash rate is kept low, the average current can be low enough
that even a small battery can last quite a while.....
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- Lighthouse LED Flasher
This was originally designed for a model in a HO train set. It simulates the behavior of the light from a lighthouse. The LED intensity gradually increases, then flashes with a bright light and finally decreases slowly in intensity.
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- LINE POWERED XENON FLASH TRANSMITTER
This line powered xenon flash circuit drives a small camera type flash tube. It has an optical isolator to allow the flash to be safely triggered from some remote device. A flash rate of 2Hz is possible with the circuit.
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- LOW BATTERY VOLTAGE FLASHER
This circuit is designed to monitor two alkaline cells (3v) that from 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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- Reduced Power Sequential LED Flasher
The 74HC4017 is a neat decade counter which has 10 decoded outputs. When supplied with a low frequency clock and with a LED attached to each of the outputs, an interesting ten step sequential
flasher effect can be produced. The LEDs can be configured in a wide variety of patterns of loops, lines or arrows. But, these circuits can often be power hogs. To reduce the average current needed to produce the same effect, you
can strobe the individual LEDs with a short 10mS pulse.
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- SIMPLE NITROGEN SPARK GENERATOR
Nitrogen or air sparks are very powerful light sources that produce flashes that last only a few nanoseconds. This line-powered circuit generates a continuous series of very small sparks across electrodes with a 0.05-inch gap.
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- Universal Flasher using Latching Relay: This circuit is powered by a 9v battery and controls any AC to DC load through a set of relay contacts, rated at 10 amps. To
conserve power, the circuit uses a latching relay. A variable frequency oscillator controls the flashing speed from 0.2Hz to 2Hz. A pair of pulse generators first latch the contacts closed then unlatches them open. The power
consumption is so low that a 9v battery will last for several months.
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Ultra Low Power LED Flasher NEW
The efficiency of some newer LEDs is amazing. Some of the latest green LEDs can launch blinding light with just one milliamp of current. I take advantage of one of these newer devices in
the circuit below. The flashing circuit uses a classic multivibrator oscillator, made from a tiny National Semiconductor’s LMC7215 low power voltage comparator. The circuit produces a short 10ms pulse every two seconds, drawing power from a
3v supply. I suggest using a surface mounted green LED from Kingbright.....
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