Sturdag Lagernathy
Well-known member
This is a circuit that will give a regulated, variable voltage from around 8.5vdc to 1.5vdc, if using a 9 volt supply. It also "emulates" age by throwing in a bit of capacitance (220pf) and a tiny impedance(max 200 Ohms). I sell a "real " version of this on a PCB, with a pretty case, but this works just as well. (Don't tell)
Nearly forgot the best part! No Cuts and No Links! Anyone can do this one, no excuses.
The way the outputs are arranged, "Age" and "Sag", this can mount directly on the back of either pot. If you want, the "Age" pot can be omitted, then the output should be taken from "Age1" and you don't need the 270 ohm resistor, either. This circuit was taken directly from the LM317T datasheet, section 9.2. Note the 2N5817 diode polarity, Cathode to +9vdc, its not a polarity protector, as the LM317 is internally protected from shorts and reverse polarity. the diode protects the regulator from the 100uf cap discharging through it, if the output is ever shorted. Have Fun!!
Sturdag
EDIT: Forgot to say, some "wall wart" and better power supplies hate this thing, and shut down at that slightest wiff. Also dont use on pedals with voltage doublers and the like! If the pedal uses a battery, theoretically it should be safe otherwise?
Ominous music begins....
Nearly forgot the best part! No Cuts and No Links! Anyone can do this one, no excuses.
The way the outputs are arranged, "Age" and "Sag", this can mount directly on the back of either pot. If you want, the "Age" pot can be omitted, then the output should be taken from "Age1" and you don't need the 270 ohm resistor, either. This circuit was taken directly from the LM317T datasheet, section 9.2. Note the 2N5817 diode polarity, Cathode to +9vdc, its not a polarity protector, as the LM317 is internally protected from shorts and reverse polarity. the diode protects the regulator from the 100uf cap discharging through it, if the output is ever shorted. Have Fun!!
Sturdag
EDIT: Forgot to say, some "wall wart" and better power supplies hate this thing, and shut down at that slightest wiff. Also dont use on pedals with voltage doublers and the like! If the pedal uses a battery, theoretically it should be safe otherwise?
Ominous music begins....
Last edited: