Search found 46 matches

by KeithT
May 19 2020 12:05pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

Torp claims it is 29kg https://www.torpmotors.com/torp_bike/?e ... eSpeed=off How do you get from a Light Bee at 50kg, go to 15kW and lose 21kg? Did they weigh it without the battery?
by KeithT
May 18 2020 10:28am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

KTM E-XC is heavy at 245lbs. I have a Zero FX but like the Sur-Ron much better on tight single track trails because of the light weight, power isn't everything. And I've had KTM's, 360 2 stroke and 640 ADV. Better suspension and more power than the FX but electric wins for me. A new entry is the Ubc...
by KeithT
Mar 13 2020 3:13pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

I made my own bracket, saw yours right after I got it done. I changed the rear to the Pirelli Scorpion and added a rim lock. I noticed it says "front tire" and has a direction arrow. I mounted it without looking and the arrow is now correct for a rear tire. Is it wrong? Some knobs are dished in what...
by KeithT
Mar 13 2020 1:47pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

I've added KTM 85 fenders front and rear as well as a mud flap. The rear needed some support, it was much too floppy just bolted to the stock rear. I used some 1/2 inch pvc pipe, ground to fit the sub frame pockets in the KTM fender and then attached to the front seat studs with coupling nuts. It is...
by KeithT
Feb 12 2020 6:42pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

I just put a KTM 85 front fender on my Sur-Ron X too, very happy with it, but the rear fender is next, still getting mud on my back. I made a mount from two stacked plates of 1/8 inch aluminum, tapped M6 for the four fender screws, countersunk through holes for the three Sur-Ron attachment screws. N...
by KeithT
Feb 02 2020 8:36pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

I'm an old guy on a Sur Ron in the mud too, love it. Much better on tight wet woods trail than my Zero FX. My friend is on a KTM500, way too much bike but I haven't convinced him to downsize, yet! I'm 69, he's 70.
by KeithT
Oct 24 2019 10:42am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

Wow thanks fechter! 35 flashes? Don't know if I can count that high. Zero uses groups like two then three. Anyway good to know.
by KeithT
Oct 24 2019 6:22am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

surron-what.jpg
surron-what.jpg (159.96 KiB) Viewed 3412 times
This came in the accessory kit with my new Sur Ron X Bike Black Edition that I got yesterday. Obviously it goes to the mystery battery connector and if something happens the LED will light up. What is it??? Haven't tried it yet.
by KeithT
Sep 11 2019 5:49pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

28787 but you might be out of range. My Zero could get there.
by KeithT
Oct 09 2018 2:38pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

Thanks Rix, that is helpful. I learned to ride off road in the CA high desert, so I think I know about the hills you describe. In the eastern coal country, it is rare to see 25mph on the trail. So speed is rarely a factor in getting up a hill, it is mostly traction and line choice. I'm sure more pow...
by KeithT
Oct 09 2018 1:02pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5024
Views: 519297

Re: Sur-Ron - New Mid drive Bike

I rode 2 weekends ago on super tight and hilly stuff that I couldn't climb with my SurRon. I've been riding off road on my 2016 Zero FX for 2 1/2 years now, on extremely difficult West Virginia trails. I really like it but the suspension is not as good as the Alta or KTM. But the power is plenty fo...
by KeithT
Aug 30 2018 7:06am
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

I guess my fried critter story is not over yet, but it's become a cold case. I was not able to repair the inverter that blew up. Replacing the output mosfets did not fix it, it blew up again. And I don't have enough information to troubleshoot the drive circuitry and try again. When I looked into bu...
by KeithT
Apr 27 2018 1:19pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

I just ordered a similar mosfet, but with lower max voltage and higher Rdson. More expensive but maybe worth it. How can a part with lower performance cost more? SOA. This is a Polar rather than Trench design. The market pressure for lower on resistance has led to failures due to the Spirito effect ...
by KeithT
Apr 26 2018 3:47pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

So there is some hope for my poor fried critter. I blew another first fet today, had no more spares so I replaced it with a larger type that I did have. So far, the new fet has passed every test. Is this the solution? Well, I still don't have an inverter that works. But, I've connected the HotBox to...
by KeithT
Apr 25 2018 10:49am
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Looks yummy, not! I considered posting a pic like that after the previous round. Hard to say what sequence the failures occurred. Post mortem on the inverter found a few things. Only one fet failed, I think. How many to replace is never clear, I'll do at least two. Weird design. I was surprised when...
by KeithT
Apr 24 2018 5:32pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

So my crispy guinea pig is now black and charred. I got my circuit working properly and increased the load in steps. No problem driving a 500W halogen with inrush. The switch turned it on and off reliably and there was no arcing on connect or disconnect. I then connected the inverter through a 4 ohm...
by KeithT
Apr 23 2018 2:24pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Finally got back to troubleshooting my crispy critter guinea pig Hot Box. Found a major error caused by the PC layout software. The footprint that I used for the PNP transistors is wrong, CBE instead of EBC, Q3, Q6 and Q8. That's why the protection was triggered, probably why it blew up too. We'll s...
by KeithT
Apr 03 2018 2:06pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

I haven't considered all possibilities but I think a low resistance is needed so that if the output is shorted the time spent at high current is quick, same as the time to charge the load through low resistance. This is to stay within the SOA with high current for a short time. This circuit uses loa...
by KeithT
Apr 03 2018 11:58am
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Only the first fet is shorted, the 0.5 ohms didn't save it. Maybe the second fet didn't turn on, but even that shouldn't kill it. M1 is rated 160 amps continuous, should switch in a few microseconds, well before the SOA says there's trouble. Peak possible current was 216 amps with the 108V pack I us...
by KeithT
Apr 02 2018 2:47pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

So construction is done, nice package! Sadly, destruction is done too. More casualties. The fault detector triggered even with no load. Deciding it was non-essential, I disabled it with a clip lead. Circuit then worked with a light resistive load, tried the inverter and... time to order more fets. T...
by KeithT
Mar 26 2018 3:20pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

It's getting real. Yes, a lot of parts. On to the metal work and power wiring...
hot box perf.jpg
hot box perf.jpg (85.3 KiB) Viewed 1984 times
And speaking of evolution, here are the fet sizes I've been through, starting with TO-220, then TO-247, then TO-264
fets.jpg
fets.jpg (77.2 KiB) Viewed 1980 times
by KeithT
Mar 16 2018 3:21pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Not final until I build and test, but I've firmed up the design enough to order parts. I went for the same fets I've blown up before, but this circuit will treat them with a lot more care. I'm including a switch, found it interesting that it only needs to handle about one volt dc at a milliamp. High...
by KeithT
Mar 14 2018 6:28pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Yes, quite a few parts, but a small circuit board will hold it, and only the power components have any significant cost. Cheap compared to a contactor, and should work with practically any battery pack and load, no software hacking required, just hook it up. This circuit has an initial delay of abou...
by KeithT
Mar 14 2018 10:22am
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

I've added protection for over current at turn on, no microprocessor needed, just a handful of discrete parts. Three transistors do it, Q7 turns on with the first fet and charges a timing capacitor, Q8 turns on if the load voltage doesn't come up fast enough, Q9 turns off the fets, latching the circ...
by KeithT
Mar 12 2018 12:42pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 733
Views: 91830

Re: Active pre-charge/inrush control

Yeah the resistor size is arbitrary, but there are some tradeoffs. Finding power resistor specs in joules isn't easy but there's this http://prod.sandia.gov/techlib/access-control.cgi/1981/810569.pdf The design uses a zener to regulate the second fet turn on voltage, needed because the pack could be...