Charging problem

[gbirky]

Soundguy,

I attached another scan.

I'm not sure what you are calling "the positive output from the diode bridge" (I'm no electrical engineer or electonics technician). Is that the wire I've labeled "Y"? The tractor is wired just like I've drawn it. The alternator is actually grounded through the case, so there is no wire there. Of the two wires coming from the alternator bridge circuit, the yellow one "Y", one goes only to the VR. The red wire, "R", goes to the starter solenoid hot side (where the + battery cable is attached - I circled this location on the drawing).

In reference to all of the other posts regarding voltage regulators, this is a permanent magnet type alternator - so there is no field, and therefore field current to vary.

The VR is a small thing, about 2.5 inches long, 1 inch thick, and about 1.25 inches wide. It has an aluminum case and is epoxy filled from the underside. It seems to me that this charging system could work with the VR just being a relay which grounds the "Y" wire that goes directly from the alternator bridge circuit to the VR when it detects a voltage at the battery + "R" wire above some threshold. Does that sound reasonable?

Greg

 

[jimstractors]

My original VR and my used replacement are Yanmar VR's that are sealed with epoxy and fit your description. As I related earlier, mine has 4 wires: 2 to the alternator, 1 to the starter motor + side, and the 4th seems to go to ground. So the regulator must have the diodes inside. The book I have is for a YM169D (very close to the 1401d) and it is set up that way also.
Jim

 

[gbirky]

jwjimbo,
I also have a YM1301D with the setup you are describing. The difference is that the VR for the YM1110D (without the diodes) is about $60, the one for the YM1301D (with diodes) is $100. I can swallow the $60, but $100 is a bit too salty.

By the way, I think the diode pack is normally very robust. Its the rest of the regulator that usually fails. So thats a good way for the parts business to make more money.

It would be very interesting to me to find alternatives since the alternators normally don't fail. What other VR's can we find to replace ours??? Anyone got any ideas?

Greg

 

[Keoke]

The "Y" wire shown is an AC output to the VR. It may be used to tell the VR that the alt is now charging and it is now time to close the alt to bat circuit to permit current flow to bat.
Put a voltmeter on this lead to sure that the latching signal is getting to VR.

It looks like you folks have a 1 phase, constant rate, PM, type of alternator. For a cheap, heavy duty rectifier bridge go to an auto parts house and buy the rectifier bridge from a Delco 10SI alternator (all GM cars 1965/1990). This is a nice all alum heat sink unit that will last forever with your small alt. It is a 3 phase diode bridge unit and you will only use 1 of the three taps. Buy a mini-box and plastic insulator material at Radio and stick diode bridge in box. Box must be grounded well for neg leg of dc circuit.
By the way, the "Y" ac wire is also used to run electric tachometers by converting frequency to RPM on many diesel engines.
Not having to worry about modulating field current puts this project within reach.

cheers,

 

[Soundguy]

If wired as shown, and oem, it still, looks like there are a few things missing in the schematic. Anyway, let us know what you decide.

Soundguy

 

[Soundguy]

That is the trend for most consumer grade electronics... replace, instead or repair. I can remember how easy it used to be to repair a tv... now, you pop open a 36' tv, there is the back of the huge crt, and then a circuit board about 6" x 6".
If any problem develops you trade out the main board for about 2/3's the price of the unit.... makes you wonder..

Soundguy

P.s. .. he should save the diodes.. may prove usefull later.
"By the way, I think the diode pack is normally very robust. Its the rest of the regulator that usually fails. So thats a good way for the parts business to make more money."

 

[gbirky]

Keoke,
In my case, the diode bridge is not in the VR, and the alternator and diode bridge are working. The VR is not. What I need to know is what exactly that VR does, and can it be replaced for less than the $60 I'll have to shell out for the replacement part.

Greg

 

[Soundguy]

Assuming that, there needs to be a relay or other switch in the circuit.

But I agree... if the ac voltage is there.. he has the basic makings of the charging system.. just needs to rectify it, and regulate it.. the easy parts.. as generation was the 'hard' part.

soundguy

"the "Y" wire shown is an AC output to the VR. It may be used to tell the VR that the alt is now charging and it is now time to close the alt to bat circuit to permit current flow to bat.
Put a voltmeter on this lead to sure that the latching signal is getting to VR."

 

[gbirky]

Soundguy,

As you say, it is an "interesting" and "wasteful" solution. These tractors burn so little fuel as it is, that a little extra wasted probably isn't noticed. My question still remains. Is the VR in this setup just a solid state relay that grounds the "AC output" of the alternator?

Its not that I'm not going to pay the $60 to replace the VR with the correct part, I just want to know what the darn thing does! And if there is an inexpensive equivalent solution - I'd be interested.

Greg

 

[gbirky]

Sorry there Soundguy,

I posted my question just after you posted the answer.

So the system would function properly if the VR in the diagram is just a relay to ground the AC from the alternator when the battery voltage goes above say 13.5 Volts?

Greg