SonexBuilders.net

Greetings... just received a new regulator from Sonex and have a statement and a question:

- this is a Transpo/Kohler regulator KH4309 typically used on John Deere mowers, marine engines and several motorcycles (Ducati, among others). It is exactly the same regulator available online ( http://goo.gl/E0vyVU ) for $13.00+. So more expensive (by a factor of ~3) does not necessarily equate to higher quality, sometimes simply higher mark-up/profit margins.

- the wiring diagram in the manual seems to indicate that one of the AC terminals is tied to the B+ terminal. I can't locate a schematic for this regulator, not sure why that jumper is used, but if it is indeed used/needed, how are you guys tieing those terminals together?

Thanks!

Looks like Sonex changed the voltage regulator.

I believe the old voltage regulator was based on the following patent:
https://www.google.com/patents/US4220909

You'll notice that one of the AC wires is directly connected to the positive battery terminal in the schematic. The patent describes some benefits of doing it this way.

I haven't researched the new regulator, but it looks like it probably does things the more typical way with a full-wave diode bridge inside and a means of sensing the battery voltage to charge. A result of this design is that the AC terminal is not directly connected to the battery.

Unless Sonex says otherwise, don't connect B+ to the AC tab.

There's pro's and con's of both methods and I don't know any reason for the change except maybe a supplier change.

jwd3ca wrote:this is a Transpo/Kohler regulator KH4309 typically used on John Deere mowers, marine engines and several motorcycles (Ducati, among others). It is exactly the same regulator available online ( http://goo.gl/E0vyVU )

This one says 15 amp. The AeroVee nominally puts out 20 amps. So maybe it's not the same one?

gamaxxy:

>> "Looks like Sonex changed the voltage regulator."

- looks that way based on what? The regulator that you have on your AeroVee? How does it differ?

>> "I haven't researched the new regulator, but it looks like it probably does things the more typical way with a full-wave diode bridge inside and a means of sensing the battery voltage to charge"

- what is it about it that makes it look that way to you? The photo of it on the web site? That's a lot to read in to a photo :)

>> "Unless Sonex says otherwise, don't connect B+ to the AC tab."

As I said, the Sonex wiring diagram shows that one AC tab is tied to B+. So I guess you could say that Sonex does say otherwise...

So, assuming that the tied tabs are required (prolly for voltage sensing), what's the best way to tie them. My first thought was a copper strip soldered to the two tabs, but I'm worried the heat required may be problematic. The other option is via wiring. Just wondering how those who have done it (successfully!) have done it. Thanks.

jwd3ca wrote:looks that way based on what? The regulator that you have on your AeroVee? How does it differ?

The picture on the webstore looks exactly the same as the one I received from Sonex and has the left two tabs connected:


http://www.sonexaircraft.com/eshop/cart ... ory_id=357

If the voltage regulator you received is identical in appearance to the ebay link you sent then it is almost definitely a different regulator design.

jwd3ca wrote:As I said, the Sonex wiring diagram shows that one AC tab is tied to B+. So I guess you could say that Sonex does say otherwise...

Are you referring to this wiring diagram?



If so, notice that the diagram matches the photograph of the voltage regulator Sonex used to use with the first two tabs connected, but not the one that you recently received.

jwd3ca wrote:So, assuming that the tied tabs are required (prolly for voltage sensing), what's the best way to tie them. My first thought was a copper strip soldered to the two tabs, but I'm worried the heat required may be problematic. The other option is via wiring. Just wondering how those who have done it (successfully!) have done it. Thanks.

If you tie the tabs together on a regulator that isn't designed to be operated that way, it won't work. I would guess that nobody has successfully done it that way :)

Ah, I now see what you were getting at, Chris: the previous generation of Kohel regulators came with the tabs bridged, from the factory. While the later ones don't have that bridge. Neither of mine have the bridge, so I assumed that the wire diagram, which explicitly shows them tied together, meant the builder needed to accomplish this themselves!

I hoping Joe will jump in here with the definitive answer. Maybe my originally-not-bridged-but-bridged-by-me reg. will work fine w/o the tied tabs! Either that or I ruined it by following the wiring diagram :(

Here's the new Sonex-supplied reg. No bridged tabs. My original one is identical.

jwd3ca wrote:Maybe my originally-not-bridged-but-bridged-by-me reg. will work fine w/o the tied tabs! Either that or I ruined it by following the wiring diagram :(

Yep, if the tabs are not supposed to be tied, it means there is a bridge rectifier inside. If you tie them together you are bypassing most of the rectifier circuit. I haven't done a full circuit analysis, but I think there's a good chance in this case that you didn't permanently break anything.

Here's a circuit that I suspect is similar to the design of the new regulators:
http://mastercircuits.blogspot.com/2010 ... lator.html

This is a case where if you don't think about it and just connect three wires to three tabs you should be able to swap one regulator out for the other style and never notice a difference. If the other style had bridged the tabs inside where you can't see, we'd likely never even have this discussion.

Agreed. But I do think that Sonex needs to address this ambiguity. To me, that diagram says "Jump one AC tab to B+ (unless already obviously jumped)'. Just tried my 'old' reg w/o any bridging, only seeing battery voltage (12.3 12.4) at all rpms :( And I know I'm getting 30-40 VAC from the stator wires. BTW, using GRT EIS 6000. Will attempt to try the brand new reg this afternoon. To be continued... Thanks, Chris!

Installed new regulator. No joy. STILL seeing 12.3 @ 2000 rpm. Should be over 14 :( I have a dedicated case ground, so it's not a grounding issue. Guess I better re-measure AC from stator, but it was over 40VAC previously, not holding my breath on that. GRT EIS measures bus voltage, has no relevant settings that I am aware of...