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Multidisplay LED Controller - LTC3205. . . [Linear
Technology]
Multiple
Applications of High-Power LEDs - Nowadays, high-power
light-emitting diodes (LEDs) LXHLMW1C are available in the market. These white LEDs contain
indium-gallium-nitrogen (InGaN). The LEDs emitting capacity is 20 candela (Cd). We can use these LEDs for
automatic garden lighting and wide voltage operation by applying different voltages. . . . [© EFY Enterprises
Pvt. Ltd. All rights reserved]
Multiple LED
flasher - This circuit will flash a string of LEDs,
typically 16, with direct connection to the mains and with a period adjustable between 1 and 4 seconds depending
on the setting of the 22K/1W pot. Operation at 110V should also be possible but has not been tested. . . .
Multiplexing LED Drive & 4x4 Keypad Sampling - Application Note Published 26-Aug-97. . . [Microchip]
Multipurpose
White-LED Light - Standard fluorescent lamps and their
smaller versions called compact fluorescent lamps (CFLs) radiate light in all directions (360 degree) and tend to
increase the room temperature. In emergency lights using these lamps, the battery lasts only a few hours due to
the power loss during conversion of DC into AC. These limitations can be overcome by using ultra-bright white
LEDs. . . . [© EFY Enterprises Pvt. Ltd. All rights reserved]
Multi-Segment LED Display - Lite-On LTM-Y2K19JF-03 is a surprisingly good LED display with alphanumeric, numeric, and
icon LEDs. The LED module includes all driver circuitry -- no additional transistors or resistors are necessary.
The article also describes how to create and edit a 14-segment alphanumeric LED font using Excel. . . . [Robot
Room website]
Negative 0.5
Volt Supply - This simple circuit consists of two LEDs
and a photo diode. It generates a negative voltage with a current level of a couple milliamps. It is ideal for
supplying a negative rail to low power “rail to rail” op Amp circuits, which need to have a true zero volts
output. Note: This circuit is not particularly efficient . . . [Hobby Circuit designed by David A. Johnson
P.E., 07/13/06]
Night Light from White
LED - As many of you know, I have a pet peeve with
poorly made LED night lights. Often, the light from the LED quickly fades, so within months, the light is
useless. I have posted several versions of modified night lights using higher quality components . . . [Circuit
by David A. Johnson P.E., 11/06/08]
Nine-Volt Battery Voltage
Monitor - This circuit turns on a LED whenever the
voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator,
which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by David
Johnson P.E., 07/09/06]
Notes on using LEDs and various LED drivers - . . .
Offline
Supply Drives LEDs - 04/21/11 EDN Design Idea Keep LEDs
lit when AC voltage drops. . . [by TA Babu, Chennai, India]
On/off Pushbutton Switch
with 30 Minute Timeout - I received an email from a
Discover Circuits visitor. He wanted to control power to a LED camping light he was building. He wanted to turn
the light on and off with a small pushbutton switch. He also wanted a timer so the light would not stay on longer
than 30 minutes at a time. It seems that his kids often turned lights on when going to bed and then forgot to
turn them off . . . [Circuit by David A. Johnson P.E., 01/08/12]
One Cell Flashes
White LED - 11-Dec-03 EDN Design Idea 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.
. . [by Anthony Smith, Scitech, Biddenham, Bedfordshire, UK]
One cell lights any
LED - 07/05/01 EDN Design Idea The circuit in Figure 1
allows you to light any type of LED from a single cell whose voltage ranges from 1 to 1. 5V. This range
accommodates alkaline, carbon-zinc, NiCd, or NiMH single cells. The circuit's principal application is. . . [by
Al Dutcher, Al Labs, West Deptford, NJ]
One FET controls
LED array - 04/12/01 EDN Design Idea White-LED
backlights are gaining acceptance because they offer higher reliability and simpler drive circuitry than
backlights based on CCFL (cold-cathode-fluorescent-lamp] and EL (electroluminescent] technology. As a result,
white-. . . [by Len Sherman, Maxim Integrated Products, Sunnyvale, CA]
One LED Indicates Two Power States - 12/05/96 EDN Design Idea Uses a single bicolor LED to indicate both power-on and
blown-fuse conditions. . . [by Jim Hagerman, Hagerman Technology, San Diego, CA]
One Microcontroller Pin Drives Two LEDs With Low Quiescent Current - 02/07/08 EDN Design Idea Two simple circuits allow a battery-powered microcontroller to
drive two LEDs. . . [by Antonio Muñoz, Laboratorios Avanzados de Investigación del I3A, Zaragoza, Spain, and
Arturo Mediano, PhD, GEPM University of Zaragoza, Zaragoza, Spain]
One Nimh Cell
powers White LED - There are a lot of white LED driver
circuits floating around. A popular circuit called the “Joule Thief” can drive one white LED from a single 1. 2v
or 1. 5v battery cell. Most of these circuits use one or two transistors to form a voltage boost circuit . . .
[Hobby Circuit designed by Dave Johnson P.E., 09/26/09]
One-Line Telephone Line
Status Indicator - This circuit monitors one phone
line . . . [Circuit by David Johnson P.E., 06/10/00]
One-Watt 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 . . .
[Hobby Circuit designed by David Johnson P.E., 11/06/08]
Operated Christmas
Star - . . .
Optical feedback extends white LEDs' operating life - 01/18/07 EDN Design Idea PWM-controller loop stabilizes light output. . . [by Bjoy
Santos, Intersil Corp, Milpitas, CA]
Optical
Toggle Switch using a Single Chip - . . .
Optimizing Efficiency in White LED Backlight Applications
- 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, 21-Mar-07]
Ornamental Flashing
LEDs - This circuit can flash three sets of LEDs with
different levels of Flashing. It can be used as Ornamental displays. The circuit uses a simple Astable
multivibrator built around the popular timer IC NE555. Resistors R1, R2 and capacitor C1 determines the output
frequency. When the output becomes high, Red LEDs lights first. When. . . [Circuit Posted by D Mohankumar]
Outdoor
Garden Solar Lights Circuit - This Outdoor LED Solar
Garden Lights project is a hobby circuit of an automatic garden light using a LDR and 6V/5W solar panel. During
day time, the internal rechargeable 6 Volt SLA battery receives charging current from the connected solar panel
through polariy protection diode D9 and current limiting resistor R10. If ambient. . . [Circuit Posted by D
Mohankumar]
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