1610D Volt Reg Wells VR728 no joy

blackd · Jan 2, 2005

"Are you sure the 3-leaded component isnt a transistor or other semiconductor? Is the "resistor" cylindrical with color bands around it? "

I'm not sure, but the thing I desribed as a resistor is flat, square, and very well may be a transistor. I just can't figure out what the flat plate does. It's clearly a simple bridge rectfier. I tore up the potting, therfore, the connectors in taking it apart. So, I am not sure how it was wired. Got any ideas??

Don

evofxdwg · Jan 2, 2005

CALIFORNIA:Now we are getting somewhere! With this info I may be able to figure out how to use the VR728. So based on your schematic, here is what I understand. Anybody please add info to fill in the ??? below. What do the A, F, N, E typically stand for in these alternator/regulator circuits

IG – (ignition) switched, fused, +12V thru start switch [yellow}
(interesting it shares the 10A fuse with the horn –
guess they were saving $)

L – (lamp) current sink for charge lamp (grounded when not
charging-causing lamp to illuminate) [yellow/green]

A – (???) unswitched battery (common with main switch battery feed ‘B’) [White-Red]

F – ???GUESSING maybe this stands for “Field” to the alternator [White-Black]

N - ??? to alternator N [White]

E - ??? to alternator E [Black]

I don’t have my Wells VR728 in front of me. I assume the wire colors are on your tractor, and do NOT necessarily correspond with the wire colors on the VR728 pigtail. Can you give me a reference between the pins on your schematic and the VR728 pigtail connector pins? This is looking into the VR728 pigtail connector at the pins. Can you give me the correct positions for the letters?

looking into connector:
IG........L.........A

F.........N..........E
(connector key on bottom)

evofxdwg · Jan 2, 2005

BLAKD: The 3 terminal device might be a 3 terminal voltage regulator (see http://www.national.com/ds/LM/LM341.pdf does it look like the TO220 package on the first page of the .pdf file?). But it may be a special part to produce the desired 13.5V output. The flat plate sounds like a combination heat sink and common connection point. Not sure how to repair until all components can be identified. However - I will be working on an independent design.

California · Jan 3, 2005

evofxdwg,

I'm home in town so I don't have the pinout available.

I expect the several EE's here can define A, F, N, E etc more accurately than I could. I just searched for a long-ago post that I thought covered that topic well, but I can't find it now.

blackd · Jan 3, 2005

Yup! Looks like the TO220. Copper plate used as heat sink sounds right. Now, how to put it all back together?

normde2001 · Jan 3, 2005

"Besides, it sounds like the yanmar voltage regulator is kinda unreliable. "

I'm not sure how someone can say a 25 yearold voltage regulator is unreliable; however, I believe I would just order a Yanmar regulator and get on with my life.

Soundguy · Jan 3, 2005

( The Murray schematic calls it a "Dynamo". Its interesting that a Google search has some links that say a Dynamo is an AC generator and others that call it a DC generator. )
I agree.. it is probably a permanent magnet style ( I like that design.. very robust.
As you figured.. if it was a dc gen.. it would have a comutator, and would be 'noisy' as all get out.

If it were me.. and I had a non-field controlled source of ac power.. I'd rectify and regulate it. Or perhaps.. regulate it and then rectify it. A triac circuit might be very usefull here.. ( think switching power supply ). You could also do with some big silicon.. like a 2n 3055 and make a series pass regulator.

I'd try to find something that didn't waste power though.. so no shunt regulators.. etc.

The hitachi is small, 12-13" circumferencebody was 5" deep befroe you add the fan and pulley. Very similar looking to the alternator onmy shibaru/ NH 1920 tractor.. think of it as 'grapefruit' sized.

Soundguy

Soundguy · Jan 3, 2005

( What do the A, F, N, E typically stand for in these alternator/regulator circuits
)
If it were a dc genset.. I'd say a was for armature, and f for field.

I don't think you are going to be able to use that VR as a regulator for your application. If it is a vibrating contact regulator.. it will only want to regulate field current.. your system has no provision for field current regulation.. or if it did.. it is internal and for all intents and purposes.. not able to be tweaked. The reason i mention this is I have seen some systems that use the permanent magnets to get an initial charge going, and then an internal regulator takes over and varies field current itself, based on demand and voltage level at the output stud. I'm not saying the yanmar system is like this.. just babbeling out loud.

If your vr is a vibrating contact.. i think it will be an attractive paperweight now, and you need to do some rectification, and active regulation. Lots of options available.

Soundguy

reb · Jan 3, 2005

Soundguy, I think you have it figured out. The schematic shows the generator output going directly to the battery. That means the generator has a DC output. That circuit is more sophisticated than the one on the 1610 and my 1500.
It is still an interesting project to come up with a different, and possibly more reliable, design. When I looked at it a few months ago, I concluded that if the generator is to supply any significant amount of current, heat dissipation in the circuit would not be insignificant.

Soundguy · Jan 3, 2005

On that schematic, does it show the armature directly to the battery.. or does it go thru a cutout relay? Generally if it is a dc generator.. it uses a comutator, and would need a cutout relay. However.. that is a design from the 30's 40's and 50's. I soppose it could simply use a diode pack instead of the comutator and drop straight dc to the battery.

Either way... at least the alternator/generator/dynamo..whatever is working. Since ac votls are available.. it is just 'an exercise' to get proper dc volts to the battery at this point.

Heat disipation is an issue.. but keep in mind that even old style gennies can pump out some high short term amps with correct rpm. The 6v gennies on my fords are rated for 20-25 amps.. but you can coax them to do 30 if above 1000 rpm, and you full field them. Don't want to do this too long though, as the solder may get molten!

Soundguy