Mercury voltage regulator

merc850

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I was told that this unknown-850-part.jpg is a voltage regulator, can anyone tell me how to hook it up to the old system of just stator/rectifier found on my 1975 Merc 850.
 

daveswaves

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Re: Mercury voltage regulator

You can try this, no guarantees, I have never tried it.Git it right  REGULATOR on I-6 s.jpg
 

merc850

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Re: Mercury voltage regulator

That seems to make sense it limits the DC voltage coming from the rectifier.
Thanks.
 

daveswaves

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Re: Mercury voltage regulator

That seems to make sense it limits the DC voltage coming from the rectifier.
Thanks.
Yup, it actually shunts the excess voltage to ground which is the case of the unit. It does get warm, needs to be heat sunk.
 

merc850

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Re: Mercury voltage regulator

Any idea what the voltage will be? Right now I'm getting 16 - too much for my new trigger.
 

Chris1956

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Re: Mercury voltage regulator

That device has three connections. It therefore cannot be a full wave rectifier, whihc needs four. It could be a half-wave rectifier or a zener diode. A zener diode will dump any voltage above it's rating to ground, sorta like a primative voltage regulator.
 

Laddies

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Re: Mercury voltage regulator

scan0003-1.jpg
 

daveswaves

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Re: Mercury voltage regulator

Thanks Laddies. I see by your diagram that it saturates the stator with dc to lower the input to the rectifier. Is that your understanding as well? The diagram I posted may well be wrong. It was based on the theory that it needed to shunt to ground, like a zener. I certainly defer to your expertise.
 

basstracker1970

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Re: Mercury voltage regulator

I have a 1983 mercury 80hp that had one of these installed on it. Is it a have to have on these motors or can i not use it?
 

merc850

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Re: Mercury voltage regulator

Dear Daveswaves/Laddies if diagrams 8+9 are from the Merc manual that's what I'll use, it looks to me that if the regulator fails all that will happen is the full voltage from the rectifier will pass thru.
 

Laddies

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Re: Mercury voltage regulator

Merc 850, Anytime a regular fails there is a chance of excess voltage or none at all.
Dave, when at mercury school many years ago they explained the the system worked with the red wire acting as a sensor wire and when the voltage raised to about 15 volts the regulator would bleed voltage from one side of the stator to ground through the regulator body. We have aways just disconnected the yellow to test them so I have never tested one with a OHM meter and there is no test for that type of regulator in any merc manual that I can find so, I can't say for certain if it charges the stator (which I doubt because that could effect high speed running) or bleeds to ground ( I believe it bleeds to ground)
 

j_martin

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Re: Mercury voltage regulator

I have a 1983 mercury 80hp that had one of these installed on it. Is it a have to have on these motors or can i not use it?

Dear Daveswaves/Laddies if diagrams 8+9 are from the Merc manual that's what I'll use, it looks to me that if the regulator fails all that will happen is the full voltage from the rectifier will pass thru.

Failure mode is usually smoke, sometimes major.

The battery acts as the ultimate voltage regulator. As long as the electrolyte level is maintained, there really isn't much difference in how long the battery lasts.

In other words, it'll work without the regulator, you just have to pay attention to your battery's need for water more frequently.
 
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