The front
This is an adapter that makes a 24/7 battery charger from a normal 14V power-supply. The original design is published in Funk-amateur, a German magazine. That is a very clever design and very simple, some leds, resistors and 2 relais.
It was a lot of work to get all parts in the cabinet.
I made some changes to the design. I added my desulfator and two comparators. Because the desulfator draws more current as the float charge I needed a way to start charging as the battery voltage became to low. One comparator shorts the start button as the voltage becomes to low. The other lights up a green led when the input voltage is correct. This addition is not needed for normal use.
I modified the desulfator a bit. (adding a RFC, changing an inductor) and some minor things) It is now charging a more or less dead battery. The voltage was not to bad but the max current at 14V was a few 100mA. Shoring the terminals gave no spark’s or heat. After a week it now draws 3A while charging.
