B7800 IC Regulator smoking, literally smoking

[Henro]

I guess I could be wrong about what my B2910 actually was upgraded to! It has been about 18 years. I thought it was from a generator to an alternator but...

There is no question that if a device is producing DC voltage then one output lead will be positive and the other will be negative. So it IS important to know which is which and hook them up correctly IF you are dealing with a generator.

So the B2910 has a black box that failed between the device generating voltage to charge the battery. Regardless if the source Voltage is AC or DC it needs to be a voltage regulator. If the source voltage is AC there will also be a rectifier to convert the voltage from AC to DC which the battery requires.

So from what Dave has stated both the standard and upgraded Dynamos are actually alternators. So no need to worry about the way you connect those two leads.

It is great the way people come together here to share things.

 

[200mph]

Thanks, Henro. Mine is definitely a dynamo -- not an alternator. Wish it were an alternator with internal voltage regulator because I think they're more reliable and simpler overall. However, I followed another thread and looked up a few of the parts needed to convert and it looks like that would be well over $400 if I could find the parts.

I'll be thrilled to spend the $100 and get this back together if it runs for another trouble-free 18 years. I can't believe how much work this little tractor has done. It's probably the best single tool / piece of equipment I've ever bought. (Bought it 2 years old used, with 200 hours on it in 2004.)

Thanks for your input and help. Jim

A high capacity (40 amp alternator kit) was offered through wholegoods and was half the price you're claiming for the conversion. I don't know if it is available, but the Order code is B7324 40 Amp High Capacity Alternator Kit (B2710, B2910, B7800,B2630HSD,
B3030HSD (Std. on B3030HSDC), B3200

Quick search revealed this for $217.
https://www.colemanequip.com/parts/details/KubotaParts/ALT-KIT/B7324/

Typically these wholegoods kits are complete with everything needed for the conversion including directions. If the individual parts purchased through parts the price will be much higher.

Is this an option for you at this price?

 

[Pau7220]

There are may choices for inexpensive GM & Asian single wire alternators out there. Find one to fit your brackets, add a fusible link or maxifuse, one wire to battery or starter B+ terminal, and you're done.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/283457522112

Autozone does carry them also but counter people may not be able to find them because they can't read the big SINGLE WIRE sticker on the box. It was the store manager who couldn't find it for me last time when I needed one for a Lull forklift.

 

[Ohio Kubota]

I will check it out! I was actually surprised to find that the tractor will start and run without the regulator being connected and installed. That takes some of the heat off -- I can use it and just hook the battery up to a charger as needed.

I just want the few gauges and other dash lights to work properly while my battery is charging.

Thanks again for the help. I'll see what I can find about this upgrade, but thinking right now the easiest thing is to just get a new regulator plugged in and move on. If I burn the new one up, I'll definitely be looking for another solution. To answer the question, if it's half the cost of what I was thinking to go with the upgrade, I'm very interested. Thanks.

 

[200mph]

Be aware that wholegood items can be obsoleted by Kubota at any time without warning.

Attached are the contents of the kit in the event it is helpful to anyone in the future. Info taken from https://apps.kubotausa.com/illustrated-parts/ after entering B7324