Power supply for battery amp

[Leevi]

I take this up again since I'm interested to see if this could work in practice.
I drew a schematic for the power supply of an SE amp using one 12AX7 and EL84.
The idea is that the amp is a "hybrid" amp that can be used in normal and battery mode.

When using the normal mode the batteries will be recharged. The B+ is created with
20 rechargeable batteries (180V) with 260mAh each. Theoretically the total electric charge is
should be enough for several hours playing in battery mode.

The heater circuit requires own bigger battery where 7Ah could last for 3-4h playing
without recharging?

Do you think this could work in practice?

/Leevi

[kagliostro]

To me seems that both battery charge circuits need some current regulation as to prevent inrush currents when batteries are low

an LM338T (for low voltage) and a TL783 (for B+) regulator can be the solution, remember that you must lift the ground reference to the TL783 that is rated only till 125v without any form of ground lift

http://www.ti.com/lit/ds/snvs771a/snvs771a.pdf

http://www.ti.com/lit/ds/symlink/tl783.pdf

On some Ham Radio equipment the solution was a dedicated winding on the PT with a transistor circuit to obtain high voltage from 12v batteries, but this require a special transformer that isn't easy to recover



K

[Leevi]

To me seems that both battery charge circuits need some current regulation as to prevent inrush currents when batteries are low

Yes, that's true.

/Leevi