IDENT this Voltage regulator?

[Nobags]

Howdy Gang,

Help is needed to ident this voltage regulator thanks.

If some one has the slightest idea on make n model have a go thanks.

Overvoltage issue on an aircraft engine with a car alternator. 15.8v, no adjustment available.

Three wire version?

I haven’t traced the wires back yet.

[facthunter]

Could be home made with just a diode and the case is a heat sink. With most car alternators the regulator is part of the Alternator but replaceable by just undoing two screws and taking IT and one small brush out with it. Big saving in weight going with the alternator option especially the small ones from fork lifts. They also charge at lower engine revs than Generators.  They last longer when driven by a belt rather than a gear direct off the accessories case. Nev

[Nobags]

Thanks Nev,

I thought it might be a homie! 

The alternator is a Mitsubishi car alt, I have the ident number.

It would appear to be from the around the 1990s at a guess.

I have tried an internet search for the alternator, no joy yet but early days.

Yes it’s belt driven.

 

 

Edited March 2, 2021 by Nobags

[Kyle Communications]

Looks home made so could be anything

 

[RFguy]

looks home  made, could be anything. yes !

 

suggest finding a suitable vehicle regulator for it take the alternator down to an auto electrician, or scrap yard, get something that matches....

 

 

[bushcaddy105]

An excellent quite small and relatively lightweight alternator with inbuilt 14.5 volt regulator (spot on for an Odyssey battery) is the Nippon Denso unit found on old 3-cylinder Daihatsu Charades, Suzuki Sierra's and no doubt many more Japanese origin cars of the 1980's or 1990's. I have used several over the years and they cost $5 at a swap meet. From memory they are rated at 35 amps, more than enough for as much avionics as you can carry. I've never had one fail.

[facthunter]

Perfectly appropriate. I wouldn't muck around with much else. Nev

[Nobags]

Hi flyers,

Well the silver box was in fact full of electronics! Yes I believe home made!

But........with an adjustable volt dial inside the box. Sorry I couldnt take a picture with the box open. The LAME’s hand were in the way.

End result Alternator checked OK ✅

                  Voltage regulator readjusted to 13.9v ✅

A very interesting exercise, I learnt a lot, and will promptly forget tomorrow!

I do now have a spare Bosch RE55 in my tool box if the above fix is not ok.

Thank you for your knowledge gents!

Edited March 4, 2021 by Nobags

[RFguy]

important to consider failure modes- and fuses

IE - fuses in line to battery (both sense and charge ) 
Voltage sense should have a smaller fuse because it usually has smaller wire cross section).  1A would do it.

Charge- to be rated at the minimum of the ( regulator  , wiring and alternator) limit.

Fuse blowing on the sense line should cause charge output to go to zero- otherwise the  regulator  might think the battery is flat.
 

 

Edited March 5, 2021 by RFguy

[Nobags]

1 hour ago, RFguy said:

important to consider failure modes- and fuses

IE - fuses in line to battery (both sense and charge ) 
Voltage sense should have a smaller fuse because it usually has smaller wire cross section).  1A would do it.

Charge- to be rated at the minimum of the ( regulator  , wiring and alternator) limit.

Fuse blowing on the sense line should cause charge output to go to zero- otherwise the  regulator  might think the battery is flat.
 

 

I was concerned about the fuses too, checked all satis.

i have since test flown the aircraft and the charging system is now correctly charging.

[RFguy]

Nobags, does it have a separate wire back to the battery to sense the battery voltage ?

otherwise, sensing the battery voltage through the wires causes an error in charge voltage detection because of VD (voltage drop).  .

In fact, for a hot lead acid battery, you really want to set the charging voltage DOWN to about 13.5  I think , if the battery runs at 50 deg C

why ? the temperature coefficient of a lead acid battery is negative- the hotter they get, the lower the terminal voltage.

For a nominal 13.8V battery float voltage (ALL LEAD ACID  ). 25 deg C, for each deg C, reduce the charge float voltage by 0.018V

 

for for a battery that spends its working life  at 50 deg C, the float voltage needs to be  (50-25) . -.018 +  13.8
IE 13.35V 

otherwise, the battery will always be damaged.  this is a bit rubbery because the battery will start at 25 deg C perhaps room temperature  and gradually make its way up to cowl temperature.  this might take hours, so to some degree, the battery voltage charging float set point needs to relate to the likely average temperature of the battery.

the problem is at the hot end, that's where the trouble is, so you must set the voltage for the hot condition.

The best chargers/regulators have temperature sensors on the battery to compensate.

Note : Lithium Phosphate batteries require NO temperature voltage compensation.





 

Edited March 6, 2021 by RFguy

[Nobags]

I shall get back with that answer!

[Nobags]

Update........🥴

Alternator removed for refurbishing.

Replacement Bosch Voltage regulator on way too.

All under LAME guidance and figment.