|
LED (Light
Emitting Diodes) Circuits Page 13
LED: # A
B C
D - E F - H
I - K L
M - O P- R
S T
U - V W -Z
Last Updated on:
Monday, October 03, 2011 06:08 PM |
|
| Circuits
Designed by Dave Johnson, P.E. : |
- 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.
|
|
-
Universal 3v LED Flasher
The circuit below will
flash any LED color with fixed current pulses powered by a 3v battery. It uses
a charge pump approach, which routes a constant current pulse through the LED,
regardless of the LED voltage requirement. Using this approach, white and blue LEDs,
which normally require about 3.6v can be flashed with a 3v battery. With the
component values selected, the LED is hit with 15ma current pulses lasting about
10ms every two seconds.....
|
-
Ultra Low Power LED Flasher
The efficiency of some newer LEDs is
amazing. Some of the latest green LEDs can launch blinding light with just one
milliamp of current. I take advantage of one of these newer devices in the
circuit below. The flashing circuit uses a classic multivibrator oscillator, made
from a tiny National Semiconductor’s LMC7215 low power voltage comparator. The
circuit produces a short 10ms pulse every two seconds, drawing power from a 3v
supply. I suggest using a surface mounted green LED from Kingbright.....
|
-
Ultra Low Current 3v LED
Flasher #3
This circuit takes advantage of a tiny LMC7215 low current draw voltage comparator
from National Semiconductor and a super efficient green LED from King Bright. The
3v powered circuit forms a classic pulse generator circuit, which drives the LED.
The pulse width is set at about 20ms, the pulse rate is about 0.5Hz and the peak LED
current is only 100ua. This means the average LED current is only 1ua. The overall
current draw from the 3v supply is only about 2ua. This circuit might be handy to
include in a flashlight, to it can be located in the dark. The current draw is so
low that the circuit can be powered by a tiny battery for years.
|
|
|
|
|
|
Links to electronic circuits,
electronic schematics, designs for engineers, hobbyists, students & inventors:
|
|
Ultra Low Power LED Flasher - The efficiency of some newer LEDs is amazing.
Some of the latest green LEDs can launch blinding light with just one milliamp of current.
I take advantage of one of these newer devices in the circuit below. The flashing circuit
uses a classic multivibrator oscillator, made from a tiny National Semiconductor’s LMC7215
low power voltage comparator. The circuit produces a short 10ms pulse every two
seconds, drawing power from a 3v supply. I suggest using a surface mounted green LED
from Kingbright..... [Hobby Corner Circuit by Dave Johnson] |
|
Ultra-Bright LED Lamp - ..... |
|
Ultra-simple Voltage Probe - Detects 1.8 to 220 Volts DC or AC. Minimum
parts counting. (electronic circuit added 06/07/08) |
|
Universal Flasher Circuit - LED flasher with the LM3909 IC…. [Tony van Roon's
circuit] |
|
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..... [Designed by David A. Johnson] |
|
Universal-3v-LED-Flasher - The circuit below will flash any LED color with
fixed current pulses powered by a 3v battery. It uses a charge pump approach, which
routes a constant current pulse through the LED, regardless of the LED voltage
requirement. Using this approach, white and blue LEDs, which normally require about 3.6v
can be flashed with a 3v battery. With the component values selected,..... [Designed
by David A. Johnson] |
|
Use a CFL ballast to drive LEDs - 26-Apr-07 Issue of EDN A CFL ballast can
drive a string of as many as 64 LEDs..... [Design Idea by Christian Rausch, Unterhaching,
Germany] |
|
Use an LED to sense and emit light - 14-May-09 Issue of EDN LEDs in
portable devices often show power status, battery status, or Bluetooth-connection
activity. LEDs can be major factors in determining battery life because their intensity is
directly proportional to power drain..... [Design Idea by Rafael Camarota, Altera Corp,
San Jose, CA] |
|
Using The LM317T With LED Lighting - Use an LM317T to regulate the current in
LED lighting projects…. [REUK - Renewable Energy UK website] |
|
Using the TPS61040 in High Voltage Applications - TI Application Note
(added 2/06) |
|
Valentine Heart - 18 LEDs flash at three different rates and you can use these
to create an eye-catching Valentine Heart for that special person! A template for the
heart shape can be downloaded. The circuit is kept simple (and low cost) by using the
4060B IC which is a counter and oscillator (clock) in one package. The circuit requires a
9V supply, such as a PP3 battery..... [Designed by John Hewes] |
|
Various LED Blinker Circuits - The circuit uses independent timers to flash two
light emitting diodes. Any time that light emitting diode D1 is lit__light emitting diode
D2 will be switched off. Light emitting diode D3 is on if both D1 and D2 are
off.....Circuit for model railroad trains…. [from Rob Paisley's Model Train web site] |
|
Voltage to Frequency Converter + 1uS LED Pulse Driver - This circuit receives
the signal from the above amplifier and launches powerful 1uS infrared light pulses from a
low cost LED that are frequency modulated by the audio information. The 10KHz center
frequency of the pulse stream is low enough so a standard infrared LED can emit ten times
more light than conventional long pulse techniques. The circuit is described in more
detail in the transmitter section of my Handbook of Optical Through the Air
Communications. …. [Designed by David A. Johnson] |
|
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] |
|
|
LED: #
A B
C D - E
F - H I - K L
M - O P- R
S T
U - V W -Z
|
