Created "Dec 9, 2010". New Revised Circuit at bottom of page, "August 12, 2014
More Adjustable Timer Circuits using a CD4541B IC. This Circuit has adjustable "On and Off" times and is capable of Very Short to Very Long settings, and it keeps Repeating this sequence continuously. I designed this circuit to control some home made "2 foot by 4 foot" heater panals in my garden. These heaters are Low Power (50 Watts each) and with a bit of insulation over them, they keep the earth from Freezing, even at -30 degrees Celsus. (About -23 F) This is just so I can dig up my Carrots, Beets and Parsnips, All Winter long. Its Great to have FRESH Vegitables All winter long. I am quite sure these timers can have MANY other applications also. And the Resistor/Capacitor Values can be changed to create much longer or shorter times also.
"Back To My Home Page"
The Schematic. This Circuit Randomly starts in Either the "ON" or "OFF" State. This also gives Formulas for the On & Off Time calculations.
My Revised Version.
When turned On, this Always Starts with "ON" State.
The Revised Schematic. This also gives Formulas for the On & Off Time calculations.
The Revised PCB.
The Revised Overlay Picture.
All Information in this Article is "Copyright protected". All RIGHTS RESERVED.
*Copyright © 2011 & 2014*