Have 12v AC, converted to 12v DC, motor slow

[Mikel_NY]

the install of the capacitors is done and there is no heat at idle. I retested the DC voltage and have blown another voltage regulator.

what is my next step to replacing the current type of regulator with one that will work?
i would like an off the shelf part if possible.

Please help if you can.

Known information:
-- stator output 10V AC through 45V AC
-- stator output of 150Hz at idle and 850 at top rpm
-- DC converted by a Bridge rectifier and has 10 - 4700uF capacitors in parallel.
-- current regulator is a "shunt" type wired in parallel
-- Load is 12V DC, 80 watt brush fan motor and a couple of 7 watt light bulbs continuous and very intermittent use of a 18V DC Craftsman drill motor (used to move a wing front to back on a sprint car).

 

[jim hardy]

and have blown another voltage regulator.

Another ? I missed the first one(s?)

How's it connected ?

- current regulator is a "shunt" type wired in parallel

Is it in parallel with the capacitors, on capacitor side of the bridge ? That'd explain its untimely death, trying to dump all that stored charge. See post 46.
Another caution: If it's on that side of bridge, both its wires need to be on that side = its 'ground' connected to bridge & capacitor negative not frame.

I've still not heard what is voltage with no regulator, capacitors installed after bridge, lights disconnected so they won't blow, fans on and motor at track rpm...
If that voltage doesn't hurt the fan motors we only have to fix the supply for the lights.
If that voltage is too much for the fan motors, we'll have to fix their supply as well.

A little series regulator like this should in theory handle the 7 watt lights
http://www.ebay.com/itm/High-efficiency-DC-DC-8-48V-to-12V-5A-60W-buck-step-down-power-supply-module-/301317578007?_trksid=p2054897.l5668
that one's five amp,

.

a bigger one like either of these should handle the fans, they're ten amp.. Hopefully the fans will be okay without one because they 'eat' three volts..
meaning fans will be slow until capacitor voltage reaches about 15. Hopefully that'll be just above idle.

http://www.ebay.com/itm/High-efficiency-DC-DC-15-45V-to-2V-12V-10A-buck-step-down-power-supply-module-/351180611037?_trksid=p2054897.l5659

http://www.ebay.com/itm/High-efficiency-DC-DC-15-45V-to-2V-12V-10A-buck-step-down-power-supply-module-/291247866998?_trksid=p2054897.l5658

I think Amazon sells them too.
I've never used any of those modules, hopefully somebody who has used them can chime in with reality based advice.

Your tenacity is noted and applauded.
The permanent magnet alternator is a difficult thing to co-ordinate because its voltage sags a lot with load..
They built a special purpose regulator for their needs. I'm still scratching my head over its clipping only half the cycles...
Hang in there ! "Things are lookin' up" : (courtesy Nate Owens)

http://www.sketchoholic.com/uploads/userfiles/13890/c3bcd100d2_LOOKNUP_cropped.jpg

old jim

 

[Mikel_NY]

Is it in parallel with the capacitors, on capacitor side of the bridge ?

the stator outputs AC, yellow, brown ... the regulator is in parallel at this exit of wires from the stator. the wires then go to the light bulbs still AC. the wires are then branched off and feed the bridge rectifier. the caps and fan are on DC side. the caps and fan are parallel after the BR

 

[Mikel_NY]

Is it in parallel with the capacitors, on capacitor side of the bridge ?

The reg is on AC side, the caps are on DC side

 

[Mikel_NY]

I've still not heard what is voltage with no regulator, capacitors installed after bridge, lights disconnected so they won't blow, fans on and motor at track rpm...

The voltage as it sits now is 15.2V DC at fan when the motor is at 3000 rpm.

How would I test the voltage at top RPM when I have 16V caps installed? Can I overvolt them without damage?

I could test RPM to 16V and reply with an rpm w/ regulator unpluged, fan on and no bulbs.

 

[Mikel_NY]

I saw this on eBay:

http://www.ebay.com/itm/SUPERNIGHT-...501?pt=LH_DefaultDomain_0&hash=item35ce07c19dThis is a 48V DC to 12V DC regulator (for golf carts). I didn't post this before as I thought it only for the DC side, I would still need to control the AC side voltage.

The tach works by sensing the pulses from the AC stator signal. I would have to leave this part original so I know how fast the motor is running. I do not know if the tach would burn out if I sent unregulated AC to it for a long duration and installing the above regulator to control DC voltage and wire the bulbs to the DC side.

If the tack can have uncontrolled AC, I would think all else would run DC and regulated from the above regulator.

 

[jim hardy]

got it. Thannks... I'm mystified by regulator blowing.

been looking for off the shelf regulators...

some motorcycle forums are happy with this unit
http://podtronics.net/

instructions from somebody who sells them :
http://www.britcycle.com/Manuals/Podtronicinst.html

another outfit, Tympanium, seems to have become these folks :
http://www.trombetta.com/voltage_regulators.cfm
they are an oem for the industry. Briggs&Stratton i think uses them...
but i can't find where to get them.
This one looks interesting, 15 amps for single phase alternator
http://www.trombetta.com/voltage_regulators.cfm?id=60

i never saw either one, so can't endorse.

From post 35:

base test:
Fan RPM of--1840 --(Directly hooked to a 12V battery at battery V of 12.4 sat overnight, not fresh charge)

Fan RPM is--1680 at 12.30-12.40V AC / 9.7VDC engine at 1500rpm idle regulator hooked up

Fan at 15V DC, unhooked reg/no bulbs tach 2800, fan speed 2250

Fan speed: 1720-1730 @ 10.3VDC engine idle 1500, reg plugged in, one 35V 10,000 mfd installed DC side in parallel
same engine speed, fan RPM increase of 40 RPM w/ cap.

Did the extra capacitors change that very much ?

 

[jim hardy]

Your ebay gizmo is the same sort of device i was hunting.

Tach... we know nothing about it except it hasn't blown yet... Got a spare to maybe sacrifice?
What's it read with an ohmmeter ? Could work up a simple zener protector... three parts.

 

[jim hardy]

uh oh did you read fine print on that ebay golfcart regulator? I'm afraid it's for DC in from golfcart batteries..

Input range: 40V to 60V

need one that's got a wider input range... or is already made for the job like those Trombetta units.
Might find one of them to try out on a big riding lawnmower.

 

[jim hardy]

http://www.scribd.com/doc/55972644/Brigg-Stratton-Vanguard-16-Hp-Basic-Wiring-Diagram
493219 looks like that Trombetta 16 amp with charge indicator

Handy page here... http://www.briggsandstratton.com/eu/en/support/faqs/~/media/files/faqs/briggsandstratton/pdfs/alternator_specifications.pdf

 

[jim hardy]

I could test RPM to 16V and reply with an rpm w/ regulator unpluged, fan on and no bulbs.

that'd be good.

We've got to figure out how to not blow up expensive regulators...

 

[jim hardy]

Mike let's try an aftermarket regulator made for this job

check your "conversation" button...

 

[Mikel_NY]

reg unplugged, no bulb, 16V DC at 2700-2800 engine rpm.

reg plugged in, no bulb, 16V DC at 4500 engine rpm. fan speed at 1860 rpm.

I "assumed" the reg was not working when testing, the voltage would reach 15. For the above test, the voltage climbed until about 15.2 then the regulator was at its controlling limit as the voltage was bouncing all over till it reached high 15V then steady climb with engine rpm to 17V DC. ( I lost engine control, it leaned out a bit) it was at 17V for a very short time, I don't think any damage occurred.

 

[jim hardy]

Good test .

Well, so much for the fans being enough load to hold voltage down !

Caps will take brief overvoltage, no sweat.

Let's see what the aftermarket regulator does... next week...

 

[Texashorsepower]

Hello Gentleman! I just signed up and so far this thread has been a wealth of great information!

I have a snowmobile project almost like this and have some similar questions. I don't however, want to hijack Mike's thread.

Since there has been no additions to this topic for a few months does anyone have an objection to me adding a few questions of my own, directly related to the topic?

Thanks!
Russ

 

[Mikel_NY]

I don't have a problem with a parallel question . I have restarted my conversion and have received a different voltage regulator from Jim and have started rewiring it. I should be done this weekend or next.

 

[Texashorsepower]

In my project I'm converting to HID headlights. Factory setup is (2) 65watt incandescent bulbs.
I have a 2002 Polaris Edge 800 snowmobile. It has the same "clipping" style AC regulator with a half wave rectifier built into send a charge to my 12vdc starting battery.
The battery ground is common to chassis/engine ground.
The hid ballasts (2), each have an input voltage of 9-32VDC, Nominal 12.8VDC @ 3.2A, 6A max draw at startup

Initially I powered the HID lights directly from the 12vdc starting battery but, not sure of the actual charging capacity of the half wave system, drained the battery after a few hours of opperation.

My next line of thinking was if I could run the ac lighting wires through a full wave rectifier and send the rectified dc + & - to the battery to charge better than the half wave output coming from the factory regulator/rectifier. Then the power to the HIDs would continue to be smooth being powered directly off the battery. (I use rectified voltage from the headlight harness to "trigger" a 12vdc relay to provide power to the ballasts from the battery only when the sled is running), just in case you were wondering how the lights would turn on/off.

I do however remember someone saying you CAN NOT have a full wave rectified dc ground be common with an ac system ground so I'm not sure if this idea would work...

I suppose I could try running rectified dc from the headlight harness directly to the HID ballast with some caps parallel on the dc side but I don't think there would be enough capacity for the initial startup amperage required of the ballast.

I appologize if this sounds a little scatter brained, I've been interrupted a couple times while trying to write this post.

As Mike mentioned earlier, I greatly appreciate the chance to learn from those that have worlds of knowlage in this area. I know enough to get me knee deep in a fun project but the information you've provided above is awe inspiring.

Lastly, thank you Mike for letting me get some additional information on top of what I've learned from your project!

Russ

 

[Mikel_NY]

Jim sent me a regulator that changed to an ungrounded stator so both stator wires go directly to the regulator. The regulator has a 3rd wire out that is a 12 v DC positive. That would go to the battery and in my case I will be wireing 12v pos to fan motor, then founding fan 2nd wire to frame ground. The reg body will be grounded as well. The caps these people sized for me will be wired in parallel to the fan load. All this is DC. I will have to find a way to wire the tachometer to stator so it can see the rpm signal. Not clear if that part will work but so far these guys are spot on.

I hope they will stop in and help you out and finish up my project. I have been unexpectedly dealing with family matters and am just getting back working on my project.

Side note to Jim, I have not forgot about it, just sidetracked.

 

[jim hardy]

Hi Mike
i'm still in Idaho with very sparse internet availability... i am relieved you're not waiting on me !

Am thinking "what next" if that Briggs regulator doesn't do the job. Probably we'll have to go to higher voltage caps and a buck regulator, which is way more trouble.

Good Luck, and Thanks for your patience and perseverance.

old jim