Re: Info From A Lead Acid Battery On An Engine?

On Aug 17, 12:18 pm, Vladimir Vassilevsky <nos...@xxxxxxxxxxx> wrote:
eeboarder wrote:
I am developing a system that is powered from a 12V or 24V lead acid
battery configuration on an industrial engine. These are the same lead acid
batteries used in vehicles. The batteries or battery will always be charged
by an alternator running off of the engine.

Is it possible to get a run signal just from the battery?

Yes and No. It depends on the particular engine assembly.

The PIC24F
microcontroller being used needs to be able to tell if the engine is on or
off. If could monitor the engine operation(on or off) from the power
source, I wouldn't need an additional device to monitor this(oil pressure

The alternator generates the AC ripples which can be seen at the battery
terminals. You can even get the engine RPM by that ripples. However this
behaviour is stongly dependent on the particular engine and the
associated electrics, and this method won't work at all for some
engines. So, if your goal is a mass production device, I won't count on it.

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant

Hmmm....maybe use the exciter circuit thru a bridge on-board and
detect when the voltage is equalized or , as someone said, perhaps
detect the change in current flow to/from the battery. have to create
a rectifier circuit that indicates the change in current flow, but it
could be built into your on-board power supply I guess.

I dunno if I made myself clear! hah!