Im doing a home made project using an old lawn mower engine and an alternator to charge 12v batteries.
I have a CS style Delco Remy alternator which I am trying to figure out how to wire up. Its a CS style alt, so it has the case as ground, a battery out post, and then a plug with 4 additional wires, labeled S,F,L,P.
My issue is I cant figure out how to wire the the alternator's field coil. All the applications that I have seen show it in a vehicle wiring scheme with all the vehicle wiring in tact. I am trying to figure out how to get it running out of a vehicle.
I am using a 30 watt, 30 ohm resistor in series with the field coil to limit the current through it. I have played around with multiple configurations, and it appears I am energizing the coil, however I feel no magnetic pull on the alt shaft when I spin it. It spins just as freely as when I don't have current running through it.
Could anyone help me figure out how to wire the field coil?
Thanks so much for your help!
You might not feel any resistance when spinning an alternator because it needs to be spinning well above 1000rpm to make a decent charge and it needs a load to charge.
Good luck.
It should have resistance at any speed (unless CS type is different).
It is usually because there is no rotor current else stator load else no regulation (ie, not rotor current).
I am more familiar with DP types (interact with EMS) else older SIL types (Sense to battery, L to hot charge Lamp to provide tickle current else Ign on signal, and optional Ign. D+ is "L" for single wire alternators.)
But I recommend the proper regulator.... the rotor current has to vary with speed and load to keep a constant voltage output.
Or is CS an ancient external regulator type...?
I'd guess S = Sense (to battery +12V) L to charge Lamp; F to Field; & maybe P to Power (Ign +12V); with both alternator & regulator being grounded through the chassis/body. (What else could P be?)
oldspark wrote:
It should have resistance at any speed (unless CS type is different).
It is usually because there is no rotor current else stator load else no regulation (ie, not rotor current).
I am more familiar with DP types (interact with EMS) else older SIL types (Sense to battery, L to hot charge Lamp to provide tickle current else Ign on signal, and optional Ign. D+ is "L" for single wire alternators.)
But I recommend the proper regulator.... the rotor current has to vary with speed and load to keep a constant voltage output.
Or is CS an ancient external regulator type...?
I'd guess S = Sense (to battery +12V) L to charge Lamp; F to Field; & maybe P to Power (Ign +12V); with both alternator & regulator being grounded through the chassis/body. (What else could P be?)
Thanks for the responses!
This is an internally regulated alt that is most commonly used in today's vehicles.
I too am used to the older style where you can feel the EMF effect on the rotor shaft (directly associated with how much current is flowing through the field coil) without a load. Maybe having no additional load connected is why I am experiencing what I am and I actually had it hooked up correctly.
I just looked up CS alternators.
AFAIAConcerned they are merely SL alternators with 2 extra terminals (F & P) that are often not used.
Hence all you should need (eg, if a CS 130) is S to battery +12V (else alternator output (B or B+?) for testing, and L to a 12V bulb (eg, 2-3W) that goes to +12V.
Note that you may need +12V to initiate charging (eg - see novaresource's
SI to CS Alternator Conversion) - that's what the charge lamp is for - to provide a trickle or tickle current for the rotor in case the rotor has no residual magnetism (no magnet, no generation nor resistance (force) etc.)