I've seen some portable headphone amps that do it, they mention something about "floating ground". Do they simply use a voltage divider, or is it a little more complex than that?
I use two 9v batteries, in series. Gnd comes off the middle of the two, giving +/-9V. I'd guess this is what they mean...
Typically 9V batteries are rated at a current of 15mA. I wonder if that is enough?
Typically 9V batteries are rated at a current of 15mA. I wonder if that is enough?
15mA should be fine (I think)....
I really want to power it from a single battery if I can, but if not I guess I can use 2... I'll need a bigger enclosure then tho.
I really want to power it from a single battery if I can, but if not I guess I can use 2... I'll need a bigger enclosure then tho.
If you use two batteries in series, each rail will sink different amount of current then one of the batteries will die before!
So the rail splitter is better.
So the rail splitter is better.
Of cource you can use a passive voltage divider but it consumes power which could sometime be critical. It's better to use an active voltage divider, an opamp or a special IC.MikeHunt79 said:
http://focus.ti.com/lit/ds/symlink/tle2426.pdf
I prefer the two 9V myself as split supplies.
Yes you can run one battery and use a resistor voltage divider with a filter cap, and it works just fine, but if you can use two batteries, that's less parts you have to use and you get a better voltage swing with 2.
I use the +/-9V battery supply when testing freshly built amp circuit, so I can get the amp working on lower voltage, before I give it the "real" power from the mains transformer. If you accidently short the 9V batteries, no smoke most of the time.
Yes you can run one battery and use a resistor voltage divider with a filter cap, and it works just fine, but if you can use two batteries, that's less parts you have to use and you get a better voltage swing with 2.
I use the +/-9V battery supply when testing freshly built amp circuit, so I can get the amp working on lower voltage, before I give it the "real" power from the mains transformer. If you accidently short the 9V batteries, no smoke most of the time.
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