And I really can't compare against Don's build as his boards are different from our versions..
post #46 of 1817
5/2/09 at 7:18am
You need 4.75k for R27, R28..look at the schematic , on the far right edge.
I think the supplied R32 R33 resistors are actually 2 W..there may be a mistake in the BOM.
You calculate RLed based on the LED you are using and the brightness/current you want flowing through it. The Formula for it is listed on the Cavalli Audio site.
Indeed R5, R7 seem to be supplied as 47.5k when the schematic is listing it as 47 ohm..
We need Alex to chime in and correct his for us .
I wil dig in my parts bin or go pick up a few of them from the surplus store just in case.
I do have a bunch of 22 ohm resistors to use in series to get 44ohms if I don't find the 47 ohm ones at the store.
And since the internet is all about not re-inventing the wheel here's a circuit to do it:
LM555 Timer Circuits
I particularly like the one called: Delay circuit with flashing indicator LED.
Even the basic delay circuit would be useful..
It would be pretty simple to breadboard, and the main expense would probably be a relay with heavy enough contacts for the main power suppy..