jamesdeen
Newbie level 4
So I have a modular synthesizer with a +/-15VDC power supply and I'd like to power something (guitar effects pedal) that requires 9VDC.
I was initially planning to just use a 7809 off the +15 rail to get my 9V power supply, but realized that several of my pedals actually ground the positive rail to get a -9V internal supply. My thoughts was to run the 7809 through a 1:1 transformer, but I've never specced out a transformer before for isolating a DC supply and have no idea where to start.
I'd be looking at supplying about 250mA max.
I'd also like this supply to be idiot proof.. so if I short something out, or draw more than 250mA - I don't want to damage anything, or take down my +/-15VDC supply.
Maybe there's even IC's designed to deliver a 9VDC isolated supply, etc... I'm totally OK with the supply being switchmode too.
I was initially planning to just use a 7809 off the +15 rail to get my 9V power supply, but realized that several of my pedals actually ground the positive rail to get a -9V internal supply. My thoughts was to run the 7809 through a 1:1 transformer, but I've never specced out a transformer before for isolating a DC supply and have no idea where to start.
I'd be looking at supplying about 250mA max.
I'd also like this supply to be idiot proof.. so if I short something out, or draw more than 250mA - I don't want to damage anything, or take down my +/-15VDC supply.
Maybe there's even IC's designed to deliver a 9VDC isolated supply, etc... I'm totally OK with the supply being switchmode too.