TheSamba.com :: View topic - Increasing solid state voltage regulators

Thu Nov 04, 2010 8:14 pm

I got the stupid bosch solid state regulator and I need to take it down to the 25A OR increase the output of the generator. I know that is gonna require a rewind,

but is it possible to drop the Voltage regulator down to 25 amp?

Thu Nov 04, 2010 8:27 pm

Not sure I understand why...
The Bosch solid state regulator should work fine for most stuff, what are you trying to do?

The amperage rating out is just a max rating. It is capable of a 25 amp output (I guess, I don't know the actual rating) but it depends on the load. Amperage = Voltage out / load resistance.

If you are looking to adjust the voltage out, you might consider an old style mechanical regulator.

Thu Nov 04, 2010 8:59 pm

I have a porsche generator that produces 25A, well I am having touble finding a 25A regulator. So I have two solid state regulators that are 30 and they are reeking havoc on the charging system. I have heard (yea rumors) that with the gen I am running, I need a matching regulator to make the system working.

yea ohms law kicks in, V=IR
the voltage is set by the windings in the gen and is RPM dependent. Current is set as well by the gen, but the Resistance is variable and set by the volt reg. That is where I am thinking that VR is kicking the wrong signal to the field.

Fri Nov 05, 2010 7:14 am

Maybe ask the parts guy for a Porsche regulator or go to the 356/912 forums and ask where to get one. Of course it will cost more :( .
That old hotVW's article I mentioned has no part # or source for a regulator.

Fri Nov 05, 2010 7:50 am

61srnf- thanks for looking for me in the hot vws. I can not thank you guys enough for all the help. Hopefully there is a porsche meeting soon and I can hit up there swap meet.

Fri Nov 05, 2010 8:56 am

Personally, I'm surprised you're having issues myself. Where is it mounted? And if it's remote-mounted I'd run a dedicated ground wire from the screw on the generator housing to one of the bottom mounting lugs of the regulator. Also, which solid-state regulator do you have? Bosch has made two, sometime in the last year I noticed a difference -the one ending in letter "E" has no listed output rating at all, the one with an "U" on the end, shown as 30A on it.

And as I've talked about before, I don't have any idea why, but the Brazillian made version of the GR26 were stamped with a 38amp output. And if you use Ohms Law to calculate the amperage ouptput of the optional 12V generator listed in the 1961-65 VW 1200 Big Blue Bentley manual, it comes out to 37.5 amps. Not that I think that little generator is supposed to put out that much - heck, that 1969-71 Bus 38 amp generator is bigger (longer) than the normal 105mm diameter Bug.

(see this thread for more detailed talk rather than me repeating it: http://www.thesamba.com/vw/forum/viewtopic.php?t=387997& )

Anyway, if you want the proper regulator that Bosch lists as going with the GR26X, it's the 0190350049 / 30 007 points-style regulator that Bosch specified to go with the GR26X. Pelican Parts say they aren't available. GAP has them - $189.50. Looking around online, I see you can get them through Checker/O'Reilly, it says it's Bosch too, for 57 bucks.

http://shop.oreillyauto.com/ProductDetail.aspx?MfrCode=BOS&MfrPartNumber=30007 (You'll have to enter your ZIP code before this will display a match)

But it doesn't show an actual photo to know what you're actually getting. The $56.99 price tag though, I find interesting, just cracked open my old 2003-vintage Bosch Master Price List and looked up the 30007 - it was going for $56.60 List price back then. But my guess is that it's not actually a Bosch unit, and probably just a no-name points-style knockoff and may be the same as the common Bug unit.

GAP's link is this, you'll have to enter 30007 in the search box then scroll down til you find it. Look for the 189.50 price tag:

http://germanparts.com/Americart/frall.html

And then there's eBay, I see one for 150 there at the moment:

http://motors.shop.ebay.com/__?_from=R40&_trksid=m39&_nkw=%220+190+350+049%22

Now, I still have my 30007 new regulator I bought as a spare back when I was running a Brazillian GR26X.

-Andy

Fri Nov 05, 2010 10:07 am

i have the U part due to the part saying thirty in the same layout. I thought that the solid state were awesome but after two and the same problem repeatedly. I am thinking that it is sensing the increase in voltage at the reg, but not the amps, so its kicking it off saying that the output is good..

Fri Nov 05, 2010 10:12 am

I've been running the "E" regulators myself - and not had any issues like you are talking about, but mine are with normal 30amp 105mm generators. Exactly what is yours doing, undercharging or something? And, oh, you didn't respond to my question about the mounting/grounding of the regulator.

-Andy

Fri Nov 05, 2010 10:14 am

sorry, last night i placed a jumper cable from the ground to the ground of the generator. No difference made.

The problem is that its floating around 12.4, nothing higher but always lower, even with lights on, but all those details are under another thread call Getting sick of chasing this problem, electrical.

Fri Nov 05, 2010 11:11 am

Yeah, that's certainly odd. It should put out more than that - what is the dash warning light doing during all this? What does the generator put out if you unhook the regulator and do a "full output" test?

Earlier this year I put a different fan shroud on my Baja, and didn't want to drill holes in it like before where I had the regulator bolted to it, so finally got around to drill/tapping an extra hole on the generator and mounting it on there..

Fri Nov 05, 2010 11:23 am

dash light seems to be acting fine, my idle is set at 700.
Eng off- Bright on
Idle- 3/4 brightness
1000- still on but fading
1500- off
2000-off
so on-

But if I use my turn signals, the light goes on sharply but half on.
at a dark night, i can see it barely on. (like really faint on) under 2k plus RPM.

Using a multimeter- I get loosing charge when the light kicks off, I get a charge rate that is pretty good, but levels off at 12.4 nothing more.
When hooked to the gen directly, I get random out puts of the field and gen output. That really tells me the regulator is freakin out

Fri Nov 05, 2010 12:35 pm

What about the full output (unhook the regulator, ground the DF and put your meter on D+, at idle it should be around 12V, and go up very rapidly as you increase RPM, only a momentary test. Try this page too: http://www.nls.net/mp/volks/htm/gen.htm )

The glowing charging light is likely due to voltage drops in the rest of the system. I had one from a flaky ignition switch once.

Fri Nov 05, 2010 12:55 pm

yep grounded field, power output was unreal! 8 at idle exponential output from that point on.

Fri Nov 05, 2010 4:11 pm

I would think that the normal solid state regulator would work fine - just because the generator is "capable" of putting out 25A doesn't mean that you are automatically overloading the regulator, unless you are using some heavy duty accessories.
Basic stuff: the metal case of the regulator isn't touching ground anywhere, is it?

I agree that the best bet would be to find a matching regulator for that genny, though.

Sat Nov 06, 2010 11:01 am

Hey GTi, how long are you going to keep beating around the bush with the full field readings you're getting on the generator?
In your other thread you said you got 18v at something like 3k RPM. This is a 12v generator, right? 18v is not enough.

Mon Nov 08, 2010 8:36 am

jeckler- I posted in the other one, but here it is again with the field grouded:
14 at idle
16 at 1000
48 at 5000

Gen is GOOD

Dougs bugs and bunnies called there porsche expert friday and YES I need the 25 amp matchin old school regulator. The porsche master says so.....I will know more later.

Mon Nov 08, 2010 9:25 am

you asked in multiple places, you are going to get answers in multiple places. ditch the crappy solid state regulator and get an original style

http://www.thesamba.com/vw/forum/viewtopic.php?p=4938840#4938840

Mon Nov 08, 2010 9:58 am

yea, I was just asking the question specific to the voltage reg here, the problem is on the other one. This one just turned to off topic. I agree with you.

I am spending 150 for a real porsche 25A regulator new. That should fix the problem. They NEED to be matching!

Mon Nov 08, 2010 10:00 am

I'd run a regular 30A one forst just to see. I scored a nice new one on ebay for $20 shipped, I'm going that route before I spend $150 on the 25A. If it worked for Ev, I'm confident that it will work for me

Mon Nov 08, 2010 10:43 am

been there, done that, no workie....I have two solid states for sale if you want them. both in great condition, one never ran, bought to test and the other has 10 miles on it