Re: Stupid question: ammeter
Posted: Tue Nov 07, 2017 3:28 am
Simply put it boils down to the fact that the armature in a generator has wire windings and as such cannot be spun at high RPM's as an alternator (the alternator has a rotor not an armature). Therefore at idle speed the voltage cut out will open as the generator voltage will fall below the battery voltage (the cut out prevents the battery from turning the generator into an electric motor and burning it out!!).
Its entirely possible that your ammeter may show a slight discharge (minus) at idle when you have full lights on. As the engine speed increases so does the out put of the generator in both voltage and amperage, thus you will see your ammeter show a positive reading, but only until the battery is fully charged, at which point your ammeter should show only a very slight plus reading. This is all because the voltage and current regulators will effectively control the generator output to match battery charge level and load.
Your volt meter should read around 14.5 volts with the engine running at anything above idle speed. You can actually leave your volt meter on for long periods, just remember to switch it off when you turn the engine off or it will drain your battery over time. I have had my WC 57 for 10 years now, the volt meter is wired via a relay so its on as soon as the ignition is on, and I have never burned out the meter.
Cheers
Ian
Its entirely possible that your ammeter may show a slight discharge (minus) at idle when you have full lights on. As the engine speed increases so does the out put of the generator in both voltage and amperage, thus you will see your ammeter show a positive reading, but only until the battery is fully charged, at which point your ammeter should show only a very slight plus reading. This is all because the voltage and current regulators will effectively control the generator output to match battery charge level and load.
Your volt meter should read around 14.5 volts with the engine running at anything above idle speed. You can actually leave your volt meter on for long periods, just remember to switch it off when you turn the engine off or it will drain your battery over time. I have had my WC 57 for 10 years now, the volt meter is wired via a relay so its on as soon as the ignition is on, and I have never burned out the meter.
Cheers
Ian