rectifiers on small outboards

[GBC]

A mate has just installed a charge kit on his 15 hp merc.

Amps seem to be regular.

Voltage goes up and down with revs. He has only tried it in the backyard to about half throttle for 17v at half throttle. At idle it runs around 14v

The rectifier is attached to the battery, is are the electronics. The sounder reads the same voltage on the screen as the multimeter at the terminals - obviously because they are all connected at this point.
He has taken the unit back for testing and he's been told it is O.K.

Q. Will he blow up his sounder at full revs? Sounder's specs show a working range of 9-17v

Are rectifiers meant to hunt for voltage? If so what range?

Q. Should he be installing a voltage regulator somewhere in line?

[FNQCairns]

Would think 17 V is at the top of the output range for unregulated outboards, anything can happen and I have seen 16v very often over different outboards so I would say the outboard is working as designed IMO.
Would surmise the sounder equipment manufacturers would list what they consider the safest range for their voltage with a decent margin either side, if only to safeguard themselves.

Not my equipment but I would just run it or if very worried add to the electrics a regulator from any outboard from the wreckers or tandy etc.

Those coils are generators not alternators I understand? so they keep giving better charge with revs until they hit their designed wall.
If he reved it to 3000rpm as a test for 17V I bet without a tacho he probably reved it in reality to 5K and it has no more volts to give (possibly no more at 3K either?) - but of coarse only a true on the water test will prove that.

ramblings, hope it helped somewhere.

cheers fnq

[BM]

1) Check the specs for your sounder for max voltage range.

2) Continue boating... :)

if concerned:

3) Go to Jaycar electronics or a similar electronic supplier and purchase a regulator kit (in kit form). If you don't understand electronics or soldering then get someone to do it for you. You should be able to get a 14 or 15 volt regulator kit. It will need to bve capable of handling the current from your outboard which will be about 6 Amps max I believe. So if you can find a kit to 10Apms you will be fine.

Whack it into a suitable sealed small case and fit it to the powerhead somewhere (or near the battery). Cost you probably $30. Put an outboard brand name on it and it will be $150.

Cheers

[station-rat]

Hi Bm
I have had a look at the Jaycar cat and don't see any regulator kits, do you have a part number ?
Thanks
Station-rat8-)

[GBC]

Thanks for the replys all, a water test without the electronics hooked up might be in order.

Have a good week.

C.J.

[BM]

Jaycar cat no:. MP3126 but thats a 20 Amp job and a bit dear $70 odd bucks.

[station-rat]

Hi BM
I thought that a solar regulator would only go open circuit, and that this is not good for a outboard charging circuit. Is this the case or not? Any sparkies confirm this?
Station-rat8-)

[bobbyfischer]

Hi

That regulator is not suitable for your intended use. If you want to use a regulator that was designed for some other purpose make sure it can handle the frequency of the input waveform.

Regards

[BM]

Its not the most ideal regulator but could possibly be modified. Thats one I found quickly, I will search for more. I'm sure Oatley Electronics used ot have a few available but i couldn't find any on there site when I searched quickly this morning.

[station-rat]

Thanks BM
If you could find one that I could use that would be great. It is a 70HP Johnson with a 6amp output (rectifer but no regulator)
Thanks
Station-rat8-)

[RobGoesFish]

Out of curiosity, do you mind me asking approximately what the charge kit is worth? Wouldn't mid getting a kit put in my tinny.

Thanks

Rob

[Richard]

I bought a rectifier kit for my 20hp yamaha about a year ago and it was around the $60 mark. If you wanted one with a regulator it's more like $150.

I went the option without the reuglator but I'm now also concerned about the 17V that my motor is sending to the battery. The sounder (Humminbird) is supposed to be able to handle up to 32v but I'm worried about cooking the battery more than anything else.


Richard

[BM]

I'm working on a lower cost unit Station-Rat. Will know in the next couple of days if I can provide something of lower cost (well, I know I can but its a matter of how much lower)

Cheers