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White LED
(White Light Emitting Diodes) Circuits, Page 4a
White LEDs: #-B
C - KL - PQ - VW - ZLED Circuits Last Updated on:
Monday, October 03, 2011 06:09 PM
Circuits Designed by Dave
Johnson, P.E. :
Simple
WHITE LED NIGHT LIGHT
This simple circuit is designed to plug into a standard AC electrical outlet.
It uses four super bright white light emitting diodes (LED) in conjunction with a
capacitor coupled full wave rectifier circuit. The LEDs are mounted in a box and are
angled slightly to bounce the light off of a nearby wall. The light should
last about 10 years. The circuit draws less than one half of one watt of power
and can therefore run continuously. In spite of the low power, the LEDs
provide sufficient illumination for most night light applications. Circuit
component values for both 120vac and 240vac are shown.
Links to electronic circuits,
electronic schematics, designs for engineers, hobbyists, students & inventors:
Simple White LED Night Light - This simple circuit is designed
to plug into a standard AC electrical outlet. It uses four super
bright white light emitting diodes (LED) in conjunction with a capacitor
coupled full wave rectifier circuit. [Designed by David A. Johnson]
Single & Two Cell White LED Drivers Without Inductors - The
operating voltage of white LEDs coupled with my emotional need for low
cost for a given function, motivates me to make LED drivers suitable for
battery operated lanterns that can run from a small number of cells. White
and Ultraviolet LEDs.....(schematic / circuit added 6/07)
Single cell flashes white LED - 11-Dec-03 Issue of EDN Many portable
appliances and other products that must operate from a single cell are restricted to
working at very low voltages. It is thus difficult to drive white LEDs that typically
have a forward voltage of 3 to 5V. The ability to flash the LED with a supply voltage
as low as 1V presents additional complications..... [Design Idea by Anthony Smith,
Scitech, Biddenham, Bedfordshire, UK]
Solar Charged LED Utility Light - Tired of always spending money on
flashlight batteries only to have them fail just when you need them? Try this simple
circuit out. It would make an excellent science fair project. The white LEDs are quite
bright, they provide enough light to illuminate a small room at night. The LEDs
produce a nicely focused beam. You can read by the light of this device. [G. Forrest
Cook]
Solar Powered Night Light - The goal of this project was to produce a self
contained reading lamp that could be used by students in developing countries for
reading at night. The circuit can be used for a wide variety of lighting
applications..... [G. Forrest Cook]
Solar Powered Reading Lamp - The goal of this project was to produce a self
contained reading lamp that could be used by students in developing countries for
reading at night. The circuit can be used for a wide variety of lighting
applications..... [G. Forrest Cook]
Voltage-to-current converter drives white LEDs - 6/27/2002 Issue of EDN
You sometimes need to drive a white LED from one 1.5V battery. Unfortunately, the
forward voltage of a white LED is 3 to 4V. So, you would need a dc/dc converter to
drive the LED from one battery. Using the simple circuit in Figure 1, you can drive
one white LED or two series-connected green LEDs, using only a few components.....
[Design Idea by Susanne Nell, Breitenfurt, Austria]
Voltage-to-current converter drives white LEDs - 27-Jun-02 Issue of EDN
You sometimes need to drive a white LED from one 1.5V battery. Unfortunately, the
forward voltage of a white LED is 3 to 4V. So, you would need a dc/dc converter to
drive the LED from one battery. Using the simple circuit in Figure 1, you can drive
one white LED or two series-connected green LEDs, using only a few components.....
[Design Idea by Susanne Nell, Breitenfurt, Austria]
