Charging Circuit

I’ve been trying to put together a better charging control circuit for Mintball. The thing with Mintball’s control panel is that it is all low current – the heater and starter switch drive relays and the no charge light is a “fake” in that its not actually driven by the IND line off the alternator.

Being low current allows us to do sneaky things like disconnect the starter and heater buttons when the engine is running and the No Charge circuit is energised.

We do have a problem in that the Engine revs need to be quite high before the alternator excites which means the alternator is spinning at a few thousand RPM when suddenly bang – a whopping 60 amp load is placed on it, which makes the belt squeal. Obviously we need to excite the alternator at a lower speed by giving it more juice.

The circuit digram below (created using a great free application called ExpressSCH) is my first pass at a circuit that should hopefully do the job. Before anyone points out that there is no No Charge light on the diagram – it would basically be where it says “To Start / Charger circuit) which will only carry 12 volts when the ignition is on and the IND line is at 0 volts (i.e. the alternator is not producing output). I’ve a few concerns about the circuit but hopefully some minor adjustments will allay these fears

charger