Hi guys
I like to make 3 channel mixer with battery. I think to do this with 2x9V batteries. All is Ok, but I like to make phantom power from these 2 batteries.
I found step up/down inverters (MC34063 and LM1578A) but I'm not sure that this inverters can make 48V from 18VDC
Any ideas how can I make 48V from 2x9V batteries ?
Thanks
Use LM3525/3825 PWM IC and a step-up transformer to achieve your target. Switching freq should be around 100K. So Xer size will also be small.
As for the power switches, use TIP142/147 depending on your logic.
There are several ways of generating 48V from 9 or 18V. Very simple one would be voltage multiplier (X3, X4 ..) but if you need more current the LM3578 with or without external transistor can do the job.
(voltage booster: **broken link removed** )