I'm back.. lol Voltage Regulator, 1973 40hp

[393Clevor]

my 1973 40hp Evinrude didn't come with one but I got 1961 40hp given to me for parts and it had a generator on it. I got it all installed and I'm looking at regulators.. any ideas on getting one I can mount inside the cowling? are all voltage regulators the same? any ideas how many amps this puts out.. any info on this would be awesome.. btw it runs awesome I took it out last week end and it ran great.. I also installed that upgraded water pump we'll see how much better it works at lower rpms..

Thanks everyone..

 

[gm280]

Before buying anything, test to see what the generator is putting out first. Could be you won't need a regular if the voltage is good. 13~14.5 volts would be great. JMHO

 

[F_R]

As you probably already figured out, the regulator won't mount under the cowling of a 1973. And no, not all regulators are the same. Right off the bat, the OMC regulator limits output to 10 Amps. There are lots of look-alike car regulators, but no car regulator is only 10 Amps. So the next thing you will ask is why not just slap in a 30 Amp and enjoy all the extra power. Because it will burn up the generator, is why.

 

[393Clevor]

As you probably already figured out, the regulator won't mount under the cowling of a 1973. And no, not all regulators are the same. Right off the bat, the OMC regulator limits output to 10 Amps. There are lots of look-alike car regulators, but no car regulator is only 10 Amps. So the next thing you will ask is why not just slap in a 30 Amp and enjoy all the extra power. Because it will burn up the generator, is why.

Thanks.. 10amps.. now I'm getting somewhere..

 

[393Clevor]

just found a 12volt 10amp generator for a 1965 to 69 Harley Sportster so I think the regulator should work

 

[393Clevor]

thinking this should do it..

 

[gm280]

thinking this should do it..

Now that is an OLD regulator that switches things in and out mechanically. You sure you can't find something solid state to do the job?

 

[393Clevor]

Now that is an OLD regulator that switches things in and out mechanically. You sure you can't find something solid state to do the job?

still looking.. most solid state regulators say rectifier as well not sure it'll work.. I have the rectifier from the 75 Johnson not sure if it's the same thing or not..

 

[F_R]

The DC generators do NOT use a rectifier. However, I did considerable research on the 10 Amp solid state DC voltage regulators as used for replacement for the Harley mechanical regulators. Trouble is, that was a few years ago and my project sort of fell by the wayside. I'm quite convinced that is is possible there is such a thing available, if you know what you are doing.

 

[gm280]

Two issues.

First a rectifier/regulator can be used with a generator. You just need to connect it up so that the positive and negative voltages are connected correctly and therefore actually not really used to rectify the DC voltage but merely pass it through to the voltage regulator portion. But they can work if you know how to connect them.

Second, a typical LM317 variable voltage regulator could be used with a power transistor to give you the voltage AND current you need to be charging the battery. But again, you have to know what you are doing and there would be some other support components as well. But you can make one IF you understand electronics... JMHO

 

[F_R]

Two issues.

First a rectifier/regulator can be used with a generator. You just need to connect it up so that the positive and negative voltages are connected correctly and therefore actually not really used to rectify the DC voltage but merely pass it through to the voltage regulator portion. But they can work if you know how to connect them.

Second, a typical LM317 variable voltage regulator could be used with a power transistor to give you the voltage AND current you need to be charging the battery. But again, you have to know what you are doing and there would be some other support components as well. But you can make one IF you understand electronics... JMHO

I understand how the OMC system works and I also have some education in electronics (Radio/TV repair). But with all due respect, I have no idea what you just said.

As for the OMC regulator, it has three units. First is the voltage regulator, which grounds the gen field coil to make it charge and interrupts the field if the voltage goes over spec (14V). BTW, this is called a Type A field. Second is the current regulator which limits output to 10 Amps. And lastly, the cut-out relay which disconnects the generator from the battery when output is too low (idle speed). If not disconnected, the battery would discharge back through the generator at (idle or off). Admittedly, a diode could serve the cut-out rely function, which is how the solid state Harley regulators do that part.

 

[gm280]

What I was saying about a rectifier is if it is a mere single diode rectifier, the voltage from a generator being DC would simply pass through it IF is connected up properly to do so. It would act more like a steering diode then a typical AC to DC rectifier. If you use a full wave bridge setup, only two diodes would be used while the other two did nothing. So the rectifier is meaningless for the DC generator setup other then the ~0.6 voltage drop across the diodes. So if you find a rectifier/regulator, if would still work on a generator. Hope that clears it up some...

 

[393Clevor]

thanks fellas.. being only 10amps I'm thinking of fabricating a alternator in there some how.. I do a lot of trolling and at idle this won't charge much where as an alt will charge full amps at idle.. I think anyways.. Not a big deal for sure.. and I like being different.. found some small one but not small enough 4.5 inch diameter this gen is 3 inches.. might have to get creative.. anyways tight lines guys and gals.. the Harley reg will do for now.. I mean 25 bucks I got a charging system.. got the rest of it for free soooo..

 

[gm280]

If you are going for a small alternator, check some of the really little tiny vehicles being offered these days. Small engines should have equally small alternators... :decision:

 

[393Clevor]

If you are going for a small alternator, check some of the really little tiny vehicles being offered these days. Small engines should have equally small alternators... :decision:

been looking and 4.5 inch diameter is all i can find.. tell me about permanent magnet alternators.. they are small enough .. not sure if I would have to spin them up to make good power..

 

[F_R]

Alternators (and generators) make electricity by spinning a coil of wire (armature) inside a magnetic field. The magnetic field can be another coil of wire with electrical current flowing through it ---an electromagnet. Or it can be a permanent magnet. Generally speaking, the permanent magnet system is smaller and simpler. I'm not familiar with all the various alternators used today on small engines such as motorcycles and lawn mowers, but I would consider it safe to say you are not going to find such a thing that puts out more than 10 Amps, especially at slow speed. If it were possible, they wouldn't need a nuke power plant at the power company. Let us know what you find, or invent. You might become a zillionaire.

 

[gm280]

Makes me wonder if you could use a modified starter for a lawn mower and spin the starter armature and use the typical input legs as outputs? Hum...thinking cap on maybe...

 

[393Clevor]

I always thought that an alt. will put out more power at an idle then a gen.. I remember back in the day when my vw's only had gen, you had to rev them up to get them to kick in and when jump starting another car you had to rev them up to charge the dead car.. where as when you hook up a set of jumper cables to a car using an alt you got a heavy spark and you heard the car load up instantly from the dead battery... I might be way off but it always seemed that way... I just figured if I had to rig something up I might as well use an alt I thought I could get more charging power at idle with one compared to an old gen.. I mean a 1 wire alt is the balls.. easy peasy.. I'm found a small alt that might fit, I just need to source a belt or convert to a v-belt.. Found belts at Mcmaster-Carr... this should be interesting.. I'm going to use the gen for now but will be fabbing up an alt here soon.. lol I just can't leave things alone..

 

[393Clevor]

like with the heater on 10 and the wipers on everything would slow down at a stop sign until you revved up the engine.. but with an alt that never happens..

 

[gm280]

I realize you are extremely interested in recharging your battery at IDLE. But I ask, exactly why? If you are planning on idling for any length of time, the battery isn't being used for anything. And therefore, I don't understand your need to be charging the battery during that time. If you were using the battery for trolling as with a trolling motor, then you won't be idling either. So why the need to charge the battery while idling? I guess I am not understanding this need even though I contributed a few comments and suggestions along the way... :noidea: