Voltage regulator

HughN · 05 August 2012, 11:07

Hi,

My somewhat elderly outboard doesn't have a voltage regulator. Retro-fitting a Mariner one looks to be a pain in the neck as a different sub-harness would be required and I'm not convinced the space to fit one even exists.

Once it has been topped-up from the exertions of starting the battery isn't interested in drawing any more and the voltage gradually creeps up past 18V or more (at which point the Fishfinder starts to complain then switches off), then the GPS complains and switches off. With even less load being supplied the voltage creeps even higher.

I would have thought that it wouldn't be beyond the wit of man to come up with a box that takes "12V" in from the coils and provides a stabilised 12V at up to 20A on the other side. I'm darned if I can find such an animal - do such things exist, or could I use a regulator from a car / bike / van?

I don't want to have to try and make something.

Cheers
Hugh

Anchorhandler · 05 August 2012, 11:25

Hi Hugh

You could use a DC to DC converter which will guarantee you a stabilised 12v output but it all depends on what current your looking to put through it as to how cost effective that would be.

Are you sure there is no regulator fitted from new though?

Search the RS website for 'DC DC converter' and you will find quite a few. Most have a 12-36vdc input range and come in various current ratings. Technically though this will only provide you with a stabilised output voltage and not provide you with any charge regulation.

Simon

HughN · 05 August 2012, 11:49

Quote:

Originally Posted by Anchorhandler

Hi Hugh
Are you sure there is no regulator fitted from new though?

Thanks Simon.

Yep, I spent ages taking off what I assumed was a knackered voltage regulator - only to find it was the rev limiter (same shape!).

I will trawl through RS.

doggypaddle · 05 August 2012, 19:05

ask NOS4r2 i think he has used or may know how to use bike regulators. either that us use a 14.7 volt zenner as a shunt regulator? as on ole british bikes.

HughN · 05 August 2012, 20:31

Thanks.

I'm hoping this will do what I want it to. I may have to add a charge regulator to pamper the battery.

Cheers
Hugh

Trailer Guy · 05 August 2012, 20:36

I use Barden UK, for my batteries and ancillaries. Not the cheapest (though I do get a decent trade discount on batteries) but the stuff they do is good and they all know what they're talking about in my experience.

Barden UK

I bought a DC / DC convertor the other day. 12v in and 24v out (actually 27.6, because I wanted the charging version) 10A output. Think it was around £120 + vat. Gives you an idea anyway.

Peter_C · 06 August 2012, 07:00

Without much engine information to go on, are you sure it is capable of producing 20 amps? Seems like a lot for a smaller outboard...or is it a bigger on?

I used a motorcycle regulator/rectifier on my little engine. They are available for PWC's etc too.

Nos4r2 · 06 August 2012, 10:17

What motor is it and how many outputs does the alternator have?

You SHOULD be able to go to the Electrex website and look for a regulator/rectifier unit for a Kawasaki Z750 twin, or another 4 stroke bike with a 2 output alternator and replace the rectifier as well with it.

HughN · 06 August 2012, 17:43

Quote:

Originally Posted by Peter_C

Without much engine information to go on, are you sure it is capable of producing 20 amps? Seems like a lot for a smaller outboard...or is it a bigger on?

I used a motorcycle regulator/rectifier on my little engine. They are available for PWC's etc too.

The manual states 16A at 3,000 rpm so 20A was my 'upper guess' (the 25A fuse was a clue also).

Thanks

HughN · 06 August 2012, 17:44

Quote:

Originally Posted by Nos4r2

What motor is it and how many outputs does the alternator have?

You SHOULD be able to go to the Electrex website and look for a regulator/rectifier unit for a Kawasaki Z750 twin, or another 4 stroke bike with a 2 output alternator and replace the rectifier as well with it.

Thanks - I will trawl through that. It is a single output system (according to the manual)m but I am sure they will have options.

Thanks. At least I won't have to go back to my O-level Electronics text books!

Nos4r2 · 06 August 2012, 21:32

Quote:

Originally Posted by HughN

Thanks - I will trawl through that. It is a single output system (according to the manual)m but I am sure they will have options.

Thanks. At least I won't have to go back to my O-level Electronics text books!

It can't be a single output alternator-there will be at least 2 wires as the output from it.
You need to have a look at the wiring diagramme for the motor and see how many wires come out of your alternator before they get to your rectifier.

What motor is it, exactly (model and year)?

<edit> just tracked back, and seen it's a Mariner 30.

Remove the rectifier and replace it with a rectifier/regulator as I said earlier.

A1an · 06 August 2012, 21:41

Ive got all the electrics from a Mariner 60 3 cyl Im breaking.

im sure I could sort you out with a regulator for the price of the postage.

Peter_C · 06 August 2012, 23:03

Quote:

Originally Posted by A1an

Ive got all the electrics from a Mariner 60 3 cyl Im breaking.

im sure I could sort you out with a regulator for the price of the postage.

I am sorry but you are charging way too much

What an awesome offer

The only thing that really matters is, whether the op's engine is a 3 wire or 2 wire stator?

HughN · 07 August 2012, 08:17

Quote:

Originally Posted by A1an

Ive got all the electrics from a Mariner 60 3 cyl Im breaking.

im sure I could sort you out with a regulator for the price of the postage.

Fantastic, Alan. Thanks - I'll PM you with my details.

I'm sure there could be a beer in it for you, two. ;-)

HughN · 07 August 2012, 08:19

Quote:

Originally Posted by Nos4r2

It can't be a single output alternator-there will be at least 2 wires as the output from it.
You need to have a look at the wiring diagramme for the motor and see how many wires come out of your alternator before they get to your rectifier.

What motor is it, exactly (model and year)?

<edit> just tracked back, and seen it's a Mariner 30.

Remove the rectifier and replace it with a rectifier/regulator as I said earlier.

It is a Mariner 60 3 cyl 2-stroke.

I think 'single output' in the manual means that all of the coils are in series and terminate in two wires, not split into two sets (four wires) or three sets (six wires) - but that just a guess.

Cheers

A1an · 07 August 2012, 16:34

Quote:

Originally Posted by Peter_C

I am sorry but you are CHARGING way too much

What an awesome offer

Was that an intentional pun?

IMO the whole point of forums is to help and be helped.

Im a bit bored of the whole "because it has to do with a boat lets chuck another zero on it" mentality, you just need to look on eBay and see what people want/charge for what is essentially scrap parts. Ridiculous! It doesnt need to be like that. I know what its like trying to "do" boating on a budget. If I can help I will, Karma an all that.

Anyway, Hugh your part is in a jiffy bag and should be with you Thursday, hope you get some joy.

9D280 · 09 August 2012, 00:02

Genius!

Weird thing is I just fitted a Honda regulator / rectifier to my Merc.
.
Ok, i had to cut & alter all the loom connections, but call Colin at Ardoran marine, I believe he has more in his bits box....

9D280 · 12 August 2012, 23:43

Just a wee update.

Said Honda kit was strapped to the side of the air box, two of the cooling fins were filed down so i could close the lid, and a 40 odd nautical mile round trip was had with nothing higher than 14.5V seen. Compare to 16 ish V at idle before.

If any Clamshell owners want to see what i did, post & i.ll put a pic up.