Hey all.
I've been putting some research and design time into the power supply wrapper for my pedals. Here's where I got to so far:
(http://lucidtone.com/images/misc/power_supply.png)
It uses RG's P-channel MOSFET battery reversal protection, combined with an overvoltage protection circuit from EDN. the note is here:
http://www.reed-electronics.com/ednmag/archives/1996/042596/09di3.htm
It then has a phase shift oscillator combined with the Millenium 2 bypass, so that when the Millenium turns on the LED pulses at a set rate. Bear with me ;-)
The reason for the pulsing LED thing is basically so I can indicate when the battery voltage gets low. It really annoys me when I read in manuals for commercial pedals that I can tell when my battery gets low because the sound quality will go bad, or that it will refuse to switch! That's no good to me when I'm playing live. So now I want to have a way to pull the base of the oscillator high when the supply voltage is above a certain level - and conversely, when the supply voltage drops below a certain level, the status LED will pulse instead of just being steady. Low-battery indicator! :-D
I don't have a 7V Zener handy but I suspect that the Zener in red will do what I want - any ideas? I know this is kinda a more techy question than usual for here, but once I have a PCB for this I think it could benefit the community a lot. :-)
I have one old Ibanez pedal that does indicate low battery by turning the led off. But that is not as elegant as blinking led.
I have done few experimental comparator circuits with TLC271, it can be made to consume quite a little standby current. But don´t know if newer and better methods exist.
Thats real slick man. real slick. My low battery warning is a string of leds that get dimmer and dimmer.
cheers :-) the more i thought about it, the more convinced i became it'll go. i'm off to buy some zeners now, hopefully i'll have time tonight to breadboard it! :-)
AWEsome work!!! VERY INGENIOUS!!! USEFUL stuDy!!!! NIce..What's the box look like...lol !!!