- Wed Oct 30, 2013 1:56 am
#165025
Hi all,
I have an item of equipment that I need to run from a 12v DC supply. The item is a headphone amp that currently runs from a 9V AC wall wart.
Inside, the 9V AC is converted down to +9v DC, Ground and -9v DC. This supply then goes into an array of V4580L Op Amps.
I have found a point where I can inject +9v DC, ground and -9v DC and figured that the easiest way to get it running from 12v DC would be to build a dual rail power supply using a TS7809 and a TS7909 regulator.
The TS7809 is easy but i'm a bit confused about the TS7909. I've never built a -ve supply before and i'm not sure in my head how it works! Does the regulator go on the -12v line and the +12v become the ground? Where does the common ground come from? The -12v?
I have found a few examples online showing how to build a dual rail supply using the ts78xx and ts79xx but they all show a 120/240v input and i'm not sure how to modify the circuit for a 12v DC input.
Can anyone help me out here as my head is starting to hurt!
I have an item of equipment that I need to run from a 12v DC supply. The item is a headphone amp that currently runs from a 9V AC wall wart.
Inside, the 9V AC is converted down to +9v DC, Ground and -9v DC. This supply then goes into an array of V4580L Op Amps.
I have found a point where I can inject +9v DC, ground and -9v DC and figured that the easiest way to get it running from 12v DC would be to build a dual rail power supply using a TS7809 and a TS7909 regulator.
The TS7809 is easy but i'm a bit confused about the TS7909. I've never built a -ve supply before and i'm not sure in my head how it works! Does the regulator go on the -12v line and the +12v become the ground? Where does the common ground come from? The -12v?
I have found a few examples online showing how to build a dual rail supply using the ts78xx and ts79xx but they all show a 120/240v input and i'm not sure how to modify the circuit for a 12v DC input.
Can anyone help me out here as my head is starting to hurt!