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slo100
02-24-2008, 01:36 AM
I would like to use this device on a pedalboard powered by a Pedal Power AC power supply.

http://fulltone.com/PDfFiles/AB_switcher.pdf

Can this unit be modified for use with AC?

Thanks
Bret
Liam
02-24-2008, 02:17 AM
Yes, it most definitely can. Quite possibly with 1 diode, 1 resistor and 1 cap.
slo100
02-24-2008, 02:20 AM
Hello and thank you so much for your kind reply.

If you please, would you also kindly provide a schematic for such a modification?

Thanks in advance,
Bret
Liam
02-24-2008, 10:20 PM
Unfortunately not, haven't got any way of drawing or scanning one.

RG wrote some nice stuff on power supplies a while back. The basic half wave rectifer (first diagram) should be OK for what you are doing:

http://www.geofex.com/Article_Folders/Power-supplies/powersup.htm

This can be used as the diode power supply, shouldn't matter if it's a little noisy as the signal is separate from the diode circuit. The 9V AC goes in at the left, and slightly ripply 13 V DC will come out the other side.

I would suggest a 1N4002 diode and a 100 uF 25 V electrolytic capacitor as a starting point. I would also suggest going up on the resistors on the LED legs to 12k or 15k.

If the LEDs appear to flicker you might want to consider a bit more filtering, but the above should work.

Liam
slo100
02-25-2008, 12:22 AM
Ok,

I will give it a try and report what happens. If I mis-wire something, is there a significant risk of damaging the Pedal Power power supply?

The IN4002 has two "leads" and the 7809 has three "leads." How do I wire the IN4002 in the shown schematic in the link?

Sorry for the newbie questions.

Thanks
Bret
Liam
02-25-2008, 01:16 AM
What's a 7809?
slo100
02-25-2008, 01:29 AM
In the schematic located in the link you posted (geofex) there is a component labeled '7809' which I took to be a diode.

It has three leads vs. two on the diode you recommended.

Take a look at the link and you'll see.

Sorry if I mis-interpreted it.

Bret
Liam
02-25-2008, 12:19 PM
I was actually suggesting you use the first diagram for what you're making - just one diode and one capacitor. I think a regulated supply is overkill just to power 2 LEDs.

Liam
slo100
02-25-2008, 01:10 PM
Ah yes. I was looking at the wrong schematic.

Thanks so much for you assistance, Liam.

I think I am all set now.

Bret