Replacement regulator

[ShawnR]

Hi all

New user here. I have searched the forum for this sort of circuit but did not find anything. If a thread answers it already, please feel free to direct me to it so I don't waste anyone's time. Thanks.

I have had a few Kohler engines in the past ( 10 hp and now a 17 HP) I have gotten all used and they all have had their voltage regulators blown. These are about $80 here in Canada and I am reluctant to buy them if they are prone to blowing.

Here is what it is

31-8969 - Voltage Regulator Repl Kohler 25-755-03

I would like to make one. I have broken the epoxy out of the old regulator case (nope, couldn't tell what was in there) and I hope to get the new components in there when the circuit is working. They have three connections (plus the ground) so essentially an AC input from the winding and the DC positive out. It is just to charge the battery used for starting and provide some minor current for limited lighting or instruments so I suspect about 3-5 amps. The next thing I need to do is find out what the winding is actually rated for.

Having said all that, what do you think of just putting a bridge, 1000 uf cap and a LM350 in there, adjusted to about 13.8 V? I have done some searching and have found some quite elaborate battery charging circuits but don't think that is what Kohler had originally. Does anyone have an idea of what sort of circuit they might have used? I would like to limit the current to about 3 amps so as to not over charge the battery if it should become lo, ie hard starting but cannot recall if the LM350 will limit to 3 amps or just quit at 3 amps.

Any suggestions?

Thanks

Shawn

 

[Nigel Goodwin]

You first need to find out what it does, a regulator can mean many different things - and I doubt it means what you're considering.

 

[ShawnR]

Hi

Yep, it is a pretty simple situation. There is a coil in the engine that produces about 16-18 VAC and the Reg just puts out a DC voltage to replenish the battery used for starting. These engines are used in lawntractors so not much else involved. No alternator like a car and no other fancy electronics.

I guess it should be better referred to as a battery charger but for mechanics, it is called the voltage regulator.

I just went back to look at the link I posted. I see it does refer to an alternator. That might be the incorrect part, although visually, it is identical. This engine only has the lighting coil so no field terminal on an alternator or anything like that.

Thanks
Cheers,