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Lightning Lights - Schematic + Info + pictures10 LEDs light up from top to bottom, following the lightning bolt’s path. The LEDs turn off back up into the cloud. The display looks best with backlighting. The bolt seems to glow in the dark. __ Designed by Lennie Zink Li-Ion to Six White LEDs & OLED/LCD Bias - The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010
Li-Ion to Two White LEDs & OLED/LCD Bias - The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010
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 A. 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 Johnson P.E.-February, 2010
Line Powered White LEDs - The LED circuit above is an example of using 25 white LEDs in series connected to the 120VAC line. It can be modified for more or less LEDs by changing the R value. The exact resistance value will depend on the particular LEDs used. In operation, a DC voltage of around 170 is produced from the bridge rectifier and 50uF capacitor. The capacitor value is not critical __ Designed by Bill Bowden
Line Status Indicator for 1 Telephone Line - This circuit monitors one phone line . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Linear & Switcher LED Supplies Combine, Overcome Disadvantages Of Each Topology - 01/08/2013 To control their brightness, LEDs need a constant current; this can be done with a resistor placed in series with the LED string. Both the LED-string voltage and the supply voltage can vary, so a dedicated LED driver is a must to guarantee the current accuracy. Two solutions—each with advantages and disadvantages—are widely used: a linear constant-current LED driver or a step-down switching converter. Design by Fabien Franc, On Semiconductor, Phoenix
Linear Constant Current LED Lamp Dimmer - This circuits drives 24 white light LEDs with an adjustable constant current
Linear Supply for Luxeon 1W Star LEDs - Simple circuit lets you run one or more Luxeon 1W Star LEDs from a 12V DC supply. It uses low-cost parts and allows for dimming as well.__ SiliconChip
Linear-brightness controller for LEDs has 64 taps - 03/15/07 EDN-Design Ideas Digital potentiometer controls the brightness of LEDs Design by Ahmad Ayar, Maxim Integrated Products, Sunnyvale, CA
Line-powered driver lights up high-power LEDs - 06/08/06 EDN-Design Ideas LED array reduces power and maintenance expenses Design by Aaron Lager, Masterwork Electronics, Rohnert Park, CA
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
Logic Probe uses Bicolor LED - 03/13/98 EDN Ideas - (File has several circuits, scroll to this one) A project posed the challenge of replacing existing analog potentiometers (used to set brightness and contrast levels]in video monitors with digitally controlled potentiometers. The different brands and models of monitors presented widely varying voltages across the potentiometers. The design. Design by Mark Shill, Burr-Brown Corp, Tucson, AZ
Low Current Flashing LED Power Indicator This circuit flashes a power indicator LED to keep the average current low . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Low Pass Filter, 3Khz, with an Audio Amp - This circuit uses a switched capacitor filter IC from National Semiconductor to filter signals with frequencies higher than the 3KHz needed for voice audio. The schematic includes an audio amplifier that is designed to drive a standard audio head phone . . . 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 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 LED Voltmeter - This is a low power voltmeter circuit that can be used with alternative energy systems that run on 12 and 24 volt batteries. The voltmeter is an expanded scale type that indicates small voltage steps over the 10 to 16 volt range for 12 volt batteries and over the 22 to 32 volt __ Designed by G. Forrest Cook
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 Dave 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 A. Johnson P.E.-July, 2006
Low-Component-Count Logic Probe Works with TTL & CMOS
Logic - 04/07/11 EDN-Design Ideas LED's indicate logic levels. The circuit in Figure 1 uses the LM358 dual op amp running as a comparator, plus a few other inexpensive components, to make a TTL (transistor-transistor-logic) /CMOS
-logic probe. The circuit gets its power from the circuit under test, which lets it work with TTL or CMOS
logic. The IC1A and IC1B op amps come in an LM358 package. Switch S1 selects the TTL or the CMOS
mode of operation. The green LED shows logic low, and the red LED shows logic high. Design by Aruna Rubasinghe
Low-Cost Dual Digital Dice - This simple dual digital dice is based on three low-cost ICs, a few transistors and a handful of LEDs. IC1a & IC1b operate as an oscillator with a frequency of about 4kHz and this clocks IC2. The frequency of oscillation is not criticalit simply needs to be high enough to prevent cheating. IC2 and IC3 are 4516 binary counters, configured to count in binary from 1-6.__ Learning Electronics
Low-duty-cycle LED flasher keeps power draw at 4 mW - EDN-Design Ideas 01/23/13 Battery-operated equipment often will benefit from a power-on indicator. The indicator, however, can waste significant power.In situations where a low-duty-cycle blinking indicator provides an adequate indication of the power being turned on, the simple circuit described here should prove useful. Design by Marian Stofka
LT3465-1.2MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT - LT3465 Switching Regulator__ Linear Technology/Analog Devices
LT3518 Full-Featured 45V, 2.3A Switch Current LED Driver-Video Product Brief - The LT3518 is a current mode DC/DC converter with an internal 2.3A, 45V switch specifically designed to drive LEDs. The LT3518 operates as a LED driver in boost, buck and buck-boost modes. It combines a traditional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. Programmable __ Linear Technology/Analog Devices App Note, Steve Knoth-Senior Product Marketing Engineer Aug 25th 2010
LT3791 Buck-Boost Controller Drives High-Power LEDs, Charges High-Voltage Batteries - 08/29/13 EDN-Design Notes The LT®3791 is a 4-switch synchronous buck-boost DC/DC converter that regulates both constant-current and constant-voltage at up to 98.5% efficiency with a single inductor. It can deliver hundreds of watts and features a 60V input and output rating, making it ideal for driving high power LED strings and charging high voltage batteries when both step-up and step-down conversion is needed. It can also be used as a constant voltage buck-boost regulator with current limiting and monitoring for both input and output. Design by Keith Szolusha |
