|
White LED Night Light for the
Home - This project uses lethal voltages. If you are not
experienced in working with lethal voltages, read this project, but don't build it. You only have one life, and
AC power can take it from you very quickly, or leave you with terrible injuries. . . . [From Dick Cappels'
project pages]
White LED Power Failure Light
- Where I live most of the time, the AC power drops out upon occasion. This used to leave me groping around in
the dark for a flashlight. I could have bought a battery-backed up "emergency light" for about US$35, but being
basically metal boxes with floodlights attached, they would make my living room look more like a prison. And
besides, I make things like this for fun, so thinking about the problem eventually lead to the solution on this
web page. The power failure light that I eventually designed and built is housed in the plastic case from a
wall-mounted power transformer. I had accidentally destroyed the transformer by shorting its output, and had kept
the plastic case for years, just waiting for a project like this one. Since its mounted in a hand-sized
enclosure, when the power fails, it is a simple matter to walk over to the light, unplug it from the wall, and
use it like a flashlight to walk into other rooms to retrieve a flashlight. This particular lamp dims after a few
minutes, and is down to a dull glow after about 15 minutes. The glow can last for hours after that. I suspect
that this is at least partly the result of using rechargeable batteries from a surplus store. . . . [From Dick
Cappels' project pages]
White LED Power Supply Design Techniques - TI Application
Note . . .
White LED Shines from Piezoelectric-Oscillator Supply - 10-Jan-08 EDN Design Idea A piezoelectric ceramic buzzer powers a white LED from a single
cell. . . [by TA Babu, Chennai, India]
White LED
Step-Up Converter in SC70 & ThinSOT - LT1937. . .
[Linear Technology]
White LED Stroboscope - . . .
White LED Stroboscope With
Constant Duty Cycle & Constant Current Drive - Finally,
white LEDs 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, . . . [From Dick
Cappels' project pages]
White
LED-Based Emergency Lamp and 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 utilized optimally for emergency lamp and vehicle turning indication. The
circuits for the purpose are given here. . . . [© EFY Enterprises Pvt. Ltd. All rights reserved]
White LEDs powered by 24V - 24vac is a popular voltage. It is often used in low voltage lighting systems and industrial
controls. It is much less dangerous than 120vac/240vac line voltages. The circuit below is one method to
efficiently power a cluster of 7 white LEDs from 24vac . . . [Circuit by Dave Johnson P.E., 12/19/09]
White Light LED Driver with Gradual Dimming - TI
Application Note . . .
White Light LED Driver With Gradual Dimming (Rev. A) - LED
lighting designers are challenged with meeting their efficiency and reliability goals faster in advanced LED
lighting designs. LED lighting customers seeking the latest in innovative and affordable LED lighting solutions
can benefit from TI's broad product portfolio of LED drivers, AC/DC, DC/DC, power management devices, wireless
and wired interface control and embedded processors. LED designers have the option of not only controlling the
power stage, but regulating LED currents as well, eliminating the need for multiple components and reducing
system cost. . . . [Texas Instruments App Notes, 10-Jan-07]
White-LED driver backlights LCD and keypad - 11/13/03 EDN
Design Idea A simple circuit uses transistor junctions to monitor multiple temperature zones (Figure 1). The
temperature sensors are ordinary, general-purpose, low-cost, diode-connected transistors. The well-known diode
equation VBE = (kT/q) Žln (IC /IS ) shows that the. . . [by Fabien Franc, Catalyst Semiconductor, Sunnyvale, CA]
White-LED driver operates down to 1/2V supply voltage - 09/03/07 EDN Design Idea This circuit beats commercially available LED drivers, which
bottom out at 2. 5V input voltage, by operating at voltages as low as 1V. . . [by Dave Wuchinich]
White-LED Driver Touts High Efficiency - 06/12/03 EDN
Design Idea 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. . . [by Dimitry Goder, Sipex Corp, San Jose, CA]
White-LED driver uses improvised transformer - 02/15/07 EDN Design Idea Minimal component-count circuit boosts a single cell's voltage
to light an LED. . . [by Jim Grant, Scientific Controls, Orlando, FL]
White-LED flasher operates from one cell - 05/26/05 EDN Design Idea 1. 5V circuit flashes white LED. . . [by Anthony H Smith,
Scitech, Biddenham, England]
Wide Input
Range 1a LED Driver Powers High Brightness LEDs with Automotive & 12 VAC Supplies - DN1012 Design Notes (Linear Technology). . . [Linear Technology]
Wig/Wag LED Flasher - This simple circuit will flash two LEDs in an alternating fashion . . . [Circuit by David A.
Johnson P.E., 12/18/04]
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 Johnson
P.E., 01/09/11]
Yo-Yo Device - The original
yoyo was equiped with 2 LEDs that lit up when device was spinning. I decided to add a micro to give it some extra
pazazz. The trick here is to makeunit work without a power switch. The mercury switch is positioned so that it
supplies power when unit is spinning. After about 20 seconds, PIC shuts down in sleep modes, . . . [by Luhan
Monat-Mesa Arizona]
ZXSC100 Single cell DC-DC converter LED driving applications - Zetex Semiconductors Applications Note: ZXSC100 single cell DC-DC converter offers an
ideal solution to driving white LEDs in flashlights, enabling operation from a single NiCd or NiMH cell. . . .
<<<< Previous PAGE |
