This is my index page, where I will point to blog sites and forum posts I think are of special interest to anyone here on AAC (All About Circuits).
Bill's Index (blog, this page)
Introduction and PaintCAD (blog)
Some Tutorial Videos (thread, nicely done)
My Articles:
...ElectroStatic Discharge (AAC book)
...Creating a Virtual Power Supply Ground
...LEDs, 555s, Flashers, and Light Chasers (forum edition)
...LEDs, 555s, Flashers, and Light Chasers (blog, current edition)
...The 555 Projects (blog)
My Current Projects (blog)
Bill's Albums
Alternate Math Symbols
How to Display Attachments Full Size
BB Code List
555 Servo Controller
High Speed Op Amp Query
How to link text to a website
Arduino Microcontroller
555 Research Sources
Interesting websites outside AAC
The Battery University
Bill Bowden's Hobby Circuits Excellent site!
Sine Wave Oscillators A PDF abstract by TI
Bill's Index (blog, this page)
Introduction and PaintCAD (blog)
Some Tutorial Videos (thread, nicely done)
My Articles:
...ElectroStatic Discharge (AAC book)
...Creating a Virtual Power Supply Ground
...LEDs, 555s, Flashers, and Light Chasers (forum edition)
...LEDs, 555s, Flashers, and Light Chasers (blog, current edition)
...The 555 Projects (blog)
My Current Projects (blog)
Bill's Albums
Alternate Math Symbols
How to Display Attachments Full Size
BB Code List
555 Servo Controller
High Speed Op Amp Query
How to link text to a website
Arduino Microcontroller
555 Research Sources
Interesting websites outside AAC
The Battery University
Bill Bowden's Hobby Circuits Excellent site!
Sine Wave Oscillators A PDF abstract by TI
CookBook Entries
Posted 10-03-2009 at 09:41 PM by Bill_Marsden
This section will encompase basic circuits people might use. If a schematic is found to be flawed, it will be repaired or removed.
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LED Flashers, Group 1
These are basic 555 LED flashers. All of them alternate between the red and green LED.
Flasher 1 - This configuration of LEDs will work on all 555's. There are LEDs where both these colors are in the same package, in which case the LED flashes between Red and Green. If the flash rate is fast enough the Red/Green LED becomes yellow. The oscillator configuration for the 555 is a Hysteretic Oscillator. You can find out more about this configuration at:
http://forum.allaboutcircuits.com/sh...ad.php?t=15342
Flasher 2 is basically the same as Flasher 1, with a more conventional LED configuration. It is possible to chain as many LEDs as the power supply will support. Both Flasher 1 and Flasher 2 will adjust from 0.14Hz (7 seconds per flash) to much faster.
Flasher 3 is configured for approximately 1Hz. The output is the closest to a 50% duty cycle. Flasher 1 and 2 have problems with this because of the internal configuration of the 555 output drivers.
Basic LED fader, will slowly turn on and turn off a red LED. 9V battery is prefered for this circuit.
Basic PWM circuit with independent frequency control. If the comparitor is a LM339 then a 10KΩ resistor needs added between Vcc and output (not shown).
A basic simple constant current source for LEDs.
Posted 10-03-2009 at 09:47 PM by Bill_Marsden 
Updated 10-06-2009 at 02:27 PM by Bill_Marsden
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