Penny Tech (TM) - KTM AC lighting circuit - cheap DC power
Posted: Wed Jan 03, 2018 12:16 pm
Was looking for more than the paltry 30W (2.5A) DC the stock KTM XC/XCW/EXC stator (08-15?) puts out to the battery...
Namely to run some grip heaters for my delicate wee girly meat hooks, and maybe also a LED headlight, so I can see the tree I'm going to hit...
Running either of these (necessities?) from the battery on my 14 TE would drain it in short order...
Some report that grip heaters work on AC... I'm no sciencegeer however, but Symtec's on high DC will dry out my gloves palms, mmmmmm... Since I regularly stop on the trail to make (ahem intentional) snow angels.
Didn't really want to buy another TT full DC stator system ($300), nor did I want to float the ground and solder the OEM unit, etc.
From a post on ThumperTalk, some guys have been using the AC lighting circuit (~70W, at full rpm) and adding a $20 AC to DC rectifier (max 3A) from eBay, and successfully running LED's.
Ordered one up:
https://www.ebay.com/itm/LED-RECTIFIER- ... 2749.l2649
Shows up in about a week. Potted, water resistant. Its -28 out, so time for an garage session and beta test.
From the XC/XCW wiring diagram (found online for free, so caveat emptor), it looks like the AC comes right off the stator unregulated.
Checking with my Fluke... 11.8 max V AC...
Wire up rectifier into the AC lighting leads, and a jumper for the light switch... Test DC output off rectifier... 10.5 V DC max, and didn't let the smoke out, so at this juncture, it's not a rectiFIRE...
Bit of voltage loss, pushing through the diodes. Google-fu tells me the voltage loss means the diodes may be more robust and can take >3A... but the AC stator is 70W nominal so 5.8A full roar - 3A seems like a safe factor of ~50%.
Added a 3A fuse to the rectifier DC output to protect the rectifier, and ultimately the stator as I prefer riding to hiking (although a fair portion of my time is spent walking along side my bike in the bush)...
Add in the grips, fire it up, test, instant good heat, didn't blow fuse on "high".
Not sure how clean the power is, that's oscilloscope testing action I think. Not in my laboratory anyhow.
So rather than sacrifice a Baja Designs Squadron or a TrailTech HID, I hooked a cheap chinesium 18 W DC LED flood (5v-20V input rating), and it also ran nicely, maybe some flickering at idle, by eye-o-meter. For a heated grip resistor element I'm sure its acceptable.
Anyhow, spent a good 3 hours riding with the grips on high from the rectifier, and no (electrical) issues from the bike.
I'll watch for a cheap LED to mount to the bars.
Rubber side down, hope this helps, no warranty is expressed or implied.
Namely to run some grip heaters for my delicate wee girly meat hooks, and maybe also a LED headlight, so I can see the tree I'm going to hit...
Running either of these (necessities?) from the battery on my 14 TE would drain it in short order...
Some report that grip heaters work on AC... I'm no sciencegeer however, but Symtec's on high DC will dry out my gloves palms, mmmmmm... Since I regularly stop on the trail to make (ahem intentional) snow angels.
Didn't really want to buy another TT full DC stator system ($300), nor did I want to float the ground and solder the OEM unit, etc.
From a post on ThumperTalk, some guys have been using the AC lighting circuit (~70W, at full rpm) and adding a $20 AC to DC rectifier (max 3A) from eBay, and successfully running LED's.
Ordered one up:
https://www.ebay.com/itm/LED-RECTIFIER- ... 2749.l2649
Shows up in about a week. Potted, water resistant. Its -28 out, so time for an garage session and beta test.
From the XC/XCW wiring diagram (found online for free, so caveat emptor), it looks like the AC comes right off the stator unregulated.
Checking with my Fluke... 11.8 max V AC...
Wire up rectifier into the AC lighting leads, and a jumper for the light switch... Test DC output off rectifier... 10.5 V DC max, and didn't let the smoke out, so at this juncture, it's not a rectiFIRE...
Bit of voltage loss, pushing through the diodes. Google-fu tells me the voltage loss means the diodes may be more robust and can take >3A... but the AC stator is 70W nominal so 5.8A full roar - 3A seems like a safe factor of ~50%.
Added a 3A fuse to the rectifier DC output to protect the rectifier, and ultimately the stator as I prefer riding to hiking (although a fair portion of my time is spent walking along side my bike in the bush)...
Add in the grips, fire it up, test, instant good heat, didn't blow fuse on "high".
Not sure how clean the power is, that's oscilloscope testing action I think. Not in my laboratory anyhow.
So rather than sacrifice a Baja Designs Squadron or a TrailTech HID, I hooked a cheap chinesium 18 W DC LED flood (5v-20V input rating), and it also ran nicely, maybe some flickering at idle, by eye-o-meter. For a heated grip resistor element I'm sure its acceptable.
Anyhow, spent a good 3 hours riding with the grips on high from the rectifier, and no (electrical) issues from the bike.
I'll watch for a cheap LED to mount to the bars.
Rubber side down, hope this helps, no warranty is expressed or implied.