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I am hacking and circuit bending a toy into a guitar pedal. The toy takes 4xAA, so thats 6v. I want the pedal to work with my standard 9v guitar power supplies. I'm pretty sure I already fried the circuit just trying to run it off my One Spot as is, so I'm going to buy another (or two) and start again. My question is, what do I need to do to get the toy to run safely off of 9v...?

you can just try to get a 6v linear regulator, that is the simplest way. worst case get an adjustable linear regulator like lm317 and just set teh output voltage using 2 resistors, it will give a formula in the data sheet.

if you probe further maybe you can modify the toys circuts to use 9v direct but the regulator is sort of the simplest soluition in terms of time/cost/effort.

Or lift a 5 volt like so: http://www.electroschematics.com/8863/1 ... -or-lm309/

Cool. Thanks for the info. The 6v regulator is easy enough to get. Do I need to add caps on the in and out of the regulator...?

Without even looking at it, 6v battery is actually 5v dc compatible. On a 9v dc Supply a zener or regulator would work. You could even do it on a voltage divider with resistors if you want to be a low down dirty dumpster diving circuit bending noise hero.

eatyourguitar wrote:Without even looking at it, 6v battery is actually 5v dc compatible. On a 9v dc Supply a zener or regulator would work. You could even do it on a voltage divider with resistors if you want to be a low down dirty dumpster diving circuit bending noise hero.

Thanks for the info. I don't mind buying a part or component. I guess I'm looking for the most direct, straight forward way to do it. I may need to be coached on exactly how to do it if you don't mind..!! I've built lots of fx before and done tons of guitar wiring, but this is the first time I have hacked and bent something into a pedal, thus the first time dealing with this issue...

you are in luck, the datasheet tells you how its done. first diagram on page 18 of the datasheet for the 7805.

https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf

on the low down and dirty the caps are optional. you probably already have a bypass cap on the 9v supply anyway. the 5v cap cleans up the power ripple cause by the regulator only if the pedal is noisy.

eatyourguitar wrote:you are in luck, the datasheet tells you how its done. first diagram on page 18 of the datasheet for the 7805.

https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf

on the low down and dirty the caps are optional. you probably already have a bypass cap on the 9v supply anyway. the 5v cap cleans up the power ripple cause by the regulator only if the pedal is noisy.

Thanks for that info---Really good stuff. I'll post a pic of the regulator circuit before I add it to the project, juuuust to make sure I've got it right...!!

Double check the voltage of the toy. Sometimes devices use 4x batteries to double the current, so it might actually be a 3V circuit (just operating at a higher current).