I'm entering a circuit into eagle, it needs 2 batteries to make +9 and -9 Volts.
As batteries and me have a complicated and not that good relationship, i would like to use a 9v supply instead and thought that i could use an vto provide the -9v efficiently.
Looking at the data sheet http://www.intersil.com/data/fn/FN3179.pdf , i noticed that in theory, it should be easy, i basically designed a circuit like figure 14a, page 7 of the data sheet, with a protection 1N4001 diode on each part of the supply basic, and also added a 100uF cap there to stabilize the voltages.
The resulting schematic is
https://picasaweb.google.com/117920779036489015072/DIYGuitarEffects?authkey=Gv1sRgCPnM997DjvWQZQ
I wanted to be sure it would work before etching so i breadboarded it, and my DMM says i have only -0.5 Volts at the output of the negative supply.. can anyone help me understand why?
thanks in advance
Ermm... umm... just to be sure... your schematic doesn't show pin 3 connected to ground.
It is connected to ground, right...? :)
Mike
"If it ain't on the schematic, it ain't on the board!!"
So i just jumped on my feet, ran upstairs, fired the thing up, after adding a connection between pin3 and ground and it works perfectly :)
Thanks a lot .. it was late and i guess i do get distracted then :)