class H amp 70w from 12 v battery

I find this solution , and I think I will build this circuit for my battery driven amp ,for playing in the street with my bass guitar.

That kind of battery will be best for the application. and I still need info about how to design a charger for the battery, and if posible the charger can be used as a supply for use with wall plug (22ov ac trafo)

any help is wellcome jc.
Hello partyjups,
I would use sealed gelcell type lead-acid battery - these are available in different ratings quite easily.
Security alarm systems use these for backup power.
You will need to make a gellcell type charger though.
Also need large bypass capactance - 5000 uF or more.
It is worth going to a metals recycler - they are often pulled out of service due to date, not performance in security systems and just get sold for scrap metal value.
You should be able to find some good ones for only a few Kroner (scrap metal value - good way to buy some cables too!).

Regards, Eric.


2001-06-01 4:53 pm
For charging lead-acid, an important consideration is how fast you need to charge it. If overnight is okay, you can probably just float it at a constant voltage. Otherwise, you need something more sophisticated.
I built a charger using a Unitrode (now Texas Instruments) chip; it was fairly straightforward.