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LED Strobe & Contactless Tachometer - This versatile LED Strobe & Tachometer can be used to observe and measure the RPM of rotating machinery. It offers three different measurement methods and the readout is via a 2-line LCD module.__ SiliconChip
Led Strobe & Tacho Pt.2 - Last month, we published the circuit of our new LED Strobe & Tachometer and showed how to build the main unit and the strobe light. This month, we describe the assembly of the optional Photo-Interruptor and IR Reflector Amplifier boards. We also describe how the unit is used.__ SiliconChip
LED Strobe Flasher - This little circuit provides a surprisingly spectacular bright strobe flash which is adjustable with P1, the 200K trimmer potentiometer. P1, R1, R2, and C1 provide the flashrate. R1 sets the upper flashrate. The flashrate for the above circuit was measured at 12Vdc. If the supply voltage is steady or regulated, the flashrate is very stable. __ Designed by Tony van Roon VA3AVR
LED Strobe Has Independent Delay & Duration - 11-Jun-09 EDN-Design Ideas High-brightness LEDs, with independent delay and duration, find use in a visual-inspection application Design by Michael C Page, Chelmsford, MA
LED Strobe Light - Schematic + Info + pictures __ Designed by Lennie Zink
LED Torch - Based on the MAX660, designed to power three 3mm/5mm white LED's from 3V (1.5V min) , intended for replacing incandescent bulbs in small torches. __ Designed by Submitted Andre
LED Blinker uses 4 parts - EDN-Design Ideas March 26, 1998 [ NOTE
: File has multiple design, scroll for this one.] The circuit in Figure 1 is an easy-to-make attention-getter and runs for a week or longer on two AA cells. In September, I used this circuit for a school fundraiser, and it helped me generate more than $100. My dad showed me a circuit in EDN that did the same thing, but it uses more parts (see "Alternating LED flasher uses minimal parts," EDN, Nov 20, 1997, pg 104) . Design by Andy Meng, Cincinnati, OH
Led Strobe 2 - this version has been built and tested and is very simple indeedbased on alien project astable! __ Contact: P. Townshend EduTek Ltd
LED-flashlight works at voltages as low as 0.5V - 09/23/10 EDN-Design Ideas Extend the life of alkaline batteries. Design by GY Xu, XuMicro, Houston, TX
LEDs Flasher Alternately - Classic astable multivibrator using 2 transistors. Transistor is not critical. Try these: 2N4401, 2N2222, NTE123A, NTE123AP, NTE159, TUP/TUN and those in your junk box, you may find that most of them will work. __ Designed by Tony van Roon VA3AVR
LEDs or Lamps Sequencer - Very simple, versatile modular design No limits to the number of modules used in the ring __ Contact: Flavio Dellepiane, fladello @ tin.it
Light Chaser - Schematic only __ Designed by Andres de la Plaza
Light Dimmer that Doubles as Voltmeter - Measure AC mains voltage without using a multimeter. All you need to do is to slightly modify the light dimmer fitted at the base of a table lamp for use as...__ Electronics Projects for You
Light Sensor-741 Based - The circuit as shown act as a light sensor. Under normal conditions the resistance of the LDR is high, keeping pin 2 low. When light falls onto the LDR the resistance drops to a couple hundred ohms and triggers pin 2 high which biases the base of Q1 via pin 6 and R4 and in turn activates the relay __ Designed by Tony van Roon VA3AVR
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. . . Circuit by David Johnson P.E.-July, 2006
Line Powered Flashers - Scroll to find this one. Here is an unusual flasher circuit for 120VAC loads. The circuit is similar to the two-transistor flasher seen in several circuits in techlib. com except that an SCR is used __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Line Powered High Intensity 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 . . . Hobby Circuit designed by David Johnson P.E.-December, 2008
Line Powered White LED Array - There has been a lot of excitement lately in the lighting industry. Some companies are beginning to manufacture general lighting fixtures, which replace incandescent and fluorescent lamps, using LED lights. When proper heat management is designed. . . Circuit by David A. Johnson P.E.-February, 2010
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. . . Circuit by Dave Johnson P.E.-June, 2000
Little bike light using LEDs - No circuit description, schematic only__ CdS Electronic
LM3909 LED flasher - LED flasher with the LM3909 IC and runs from1.5-Volt battery. __ Designed by Tony van Roon VA3AVR
Low Battery Indicator - File contains several designs, please scroll to find this circuit. Here is a low battery indicator that flashes a lamp when the battery voltage falls below about 5 volts. The circuit draws about 25 microamps when not flashing so battery life is not significantly shortened by the circuit. The two 1 megohm resistors set the switching point at V/2 (plus a little due to the emitter-base diode drop) and when this voltage is above the zener voltage the circuit cannot turn on. When the battery voltage drops below 5 volts, the base voltage drops to 2.5 volts and the emitter can reach a voltage sufficient to turn on the PNP (2N4403 or similar) . When the PNP conducts, the NPN also conducts dropping the voltage across the circuit even more and the circuit snaps on. When the 4.7 uF capacitor has discharged, the circuit turns off and the capacitor begins charging again. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Low Battery Indicator Ii - This circuit indicates the remaining battery life bAy varying the duty cycle and flash rate of an LED as the battery voltage decreases. In fact, the circuit actually indicates five battery conditions: (1) a steady glow assures indicates that the battery is healthy; (2) a 2Hz flicker (briefly off) indicates that the battery is starting
Low Battery Voltage Flasher - This circuit is designed to monitor two alkaline cells (3v) that form the battery often used in portable electronic equipment. . . Circuit by David A. Johnson P.E.-January, 1998
Low Current Flashing LED Power Indicator - This circuit flashes a power indicator LED to keep the average current low . . . Hobby Circuit designed by David Johnson P.E.-June, 2000
Low Power Blink LED - Schematic only, no circuit description __ Designed by Rob Crockett
Low Power LED Flasher - Judging from the numerous references I have received, this electronic circuit, hobby circuit seems to be rather popular. Many published circuits which flash LEDs need 3 or more volts. This electronic circuit uses only a single inexpensive C-MOS IC and . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Low Power LED Flasher - It doesn't get much simpler than this circuit. Four components counting the battery! How can an LED be illuminated by a 1.5V circuit, when the forward voltage of an LED is about 2V? The LM3909 uses the 100uF capacitor as a charge reservoir, building up a voltage of about 2V before discharging the cap through the LED.
Low Power Sequential Flasher using 10 LEDs - A while back I posted a flasher circuit which flashed 10 LEDs sequentially. That circuit was powered by four AA alkaline cells. The circuit below operates much the same way but has been modified to run from a single 3v CR2032 lithium coin cell . . . Hobby Circuit designed by David A. Johnson P.E.-April, 2011
Low Power Universal LED Flasher - This low power LED flasher circuit draws about 100ua from any DC power supply ranging from 3 volts to 24 volts. The 1.0Hz 10ms LED pulsed current is held to a constant 10ma. . . Circuit by David Johnson P.E.-July, 2006 |
