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Voltage Reference Stabilizes Current Sink - 18-Feb-10 EDN-Design Ideas Produce a stable current for long-term component testingAnalog circuits for long-term testing of passive components, such as 0.1%-tolerant resistors or high-intensity white LEDs, often require a constant current. Using two op amps and a voltage reference, you can develop a circuit that provIdeas a constant-current sink with a variable setting of 0 mA to 0.99A. The circuit in Figure 1 sinks a stable current through the load. The load current is insensitive to power-supply-voltage variations. __ Circuit Design by Suded Emmanuel, Emmanuel’s Controls, Auckland, New Zealand Voltage Regulator controls scanner Lamp brightness - 05/13/99 EDN-Design Ideas An image-scanning device performs best when the scanner IC controls the brightness of the image reflected into the light sensors. The best way to control brightness is by adjusting the intensity, or light output, of the fluoresce Design by Chester Simpson, National Semiconductor, Santa Clara, CA
Welch Scientific Model 2153C Stroboscope - Here is a schematic for a typical line operated variable rate stroboscope. This unit is from Welch ScientificModel 2153C Stroboscope. These things typically gather dust in the dusty dark corners of high school physics labs. __ Designed by Don Klipstein
White LED Array that is Lined Powered - 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 . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2010
White LED driver provides 64 step logarithmic dimming - 10-Jun-04 EDN-Design Ideas The circuit of Figure 1 is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3V source and adjusts the total LED current from 1 to 106 mA in 64 steps of 1 dB each. The driver is a charge pump that mirrors the current ISET (sourced from IC3's SET terminal] to produce a current o Design by William Hadden, Maxim Integrated Products, Sunnyvale, CA
White LED Head Lamp - A white LED head lamp which can operate with only two AA batteries. The LEDs are driven in constant current, so that the brightness is maintained until end of battery life. __ Designed by The Electronic Lives Manufacturing-presented Chan
White LED Stroboscope with Constant Duty Cycle & Constant Current Drive - Finally, white LED's are bright enough to use in a practical stroboscope. This circuit can operate as a bench-top stroboscope that, in conjunction with an oscilloscope or frequency meter and bench top power supply can accurately measure rotational speeds, or it can be operated hand-held from a single 9V battery, __ Designed by Dick Cappels
White LED-Based Emergency Lamp & Turning Indicator - White LEDs are replacing the conventional incandescent and fluorescent bulbs due to their high power efficiency and low operating voltage. These can be utilised optimally for emergency lamp and vehicle turning...__ Electronics Projects for You
White-LED Driver Touts High Efficiency - 12-Jun-03 EDN-Design Ideas White LEDs, the most recent addition to the LCD backlight, find common use in providing backlight for color LCDs. Thanks to their size and white-light output, they appear in small, portable devices with color displays, such as PDAs and cellular phones. Like other LEDs, a white LED needs a constant-current source—typically, on the order of 15 to 20 mA Design by Dimitry Goder, Sipex Corp, San Jose, CA
White-LED flasher operates from one cell - 05/26/05 EDN-Design Ideas 1.5V circuit flashes white LED Design by Anthony H Smith, Scitech, Biddenham, England
Wig/Wag LED Flasher - This simple circuit will flash two LEDs in an alternating fashion. . . Circuit by Dave Johnson P.E.-December, 2004
Wireless bicycle brake light - 04/17/14 EDN-Design Ideas The TI LDC1000 senses bike wheel rotation and controls a stop light. My submission video shows the new Texas Instrument's LDC1000 attached to the rear wheel fork of a bicycle, where it senses the spokes as the wheel rotates. This proof-of-concept demonstration shows how perfect this sensor is for my goal of an improved bicycle brake light that has many advantages. I'm passionate about getting this invention completed and on the market as soon as possible, where it can help prevent some of the many injuries and deaths to the hundreds of millions of the world's bicyclists each year. Design by John Craig
Wireless LED Flasher - There are times when you would like to flash a LED through a thick plastic case without wires. The circuit below performs this feat. It can be powered from a supply ranging from 3v to 6v. It draws about 300ua of average current at 5v. . . Circuit by David A. Johnson P.E.-January, 2011
Xenon flash valve - An experiment of the xenon flash valve. __ Designed by The Electronic Lives Manufacturing-presented Chan
Xenon Flasher - You are going to like this project. It costs less than $3.00, contains six BUI - LDING BLOCKS, re-cycles a disposable flash camera and you are going to learn a lot about electronics.
Everyone has seen a disposable flash camera. __ Designed by Collin Mitchell
Xenon Lamp Flash Detector Amplifier - This circuit has a very low standby current requirement yet has very high sensitivity toward the light flashes from a xenon lamp. When connected to a flip/flop it can serve as an on on/off Controller. . . Circuit by David Johnson P.E.-December, 2004
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. . . Circuit by David Johnson P.E.-June, 2000
Xenon Strobe Light - A xenon flash tube is a triggered gas discharge device. A voltage may be impressed across the tube and it will not conduct until the xenon gas is ionised by an external high voltage (typically 3 to 5kV) . Once triggered, the gas becomes a very low impedance, and discharges the storage capacitors in about 1ms (this varies considerably, but this figure is fine for basic calculations) __ Designed by Rod Elliott ESP
Xenon Strobe Light - Disco anyone? Actually, this strobe serves a much more useful purpose then making it look cool when you dance in the dark. You can use it to view fast moving objects, look for craks in PC boards (hold the strobe on the trace side of the board and look from the component side) , and it is a great attention getter in a store window __ Designed by Aaron Cake
Xmas Lights Tester - Like every year around the same time, I hurried to get my Christmas tree all set up and the first thing we do when the tree is 'standing' we like to hang the lights in the tree. Okay, better first test them before putting all 50 of them in the tree. Yep! Working beautifully. I started a carefully planned organization of the lights so they would be evenly divided over the branches. Now the second string of lights, tested, yep working. In the tree with them. Putting the plugs into the receptacle andoh no-- one series of them are on in full glory, all the others are out. Annoyed I tried to 'fix them' by trying to push each bulb further into their sockets. Still no go __ Designed by Jan Hamer
XXI Century Sundial-NoW for Arduino also - This is a simple project of a sundial wherein the pinion is replaced by a line LASER I took from a LASER level. The LASER is mounted on a RC servo which in turn is driven by a micro controller. The micro controller keeps the time and turns the RC __ Designed by Radio LocMan |
