Search found 4313 matches

by Jeremy Harris
Jan 04, 2013 3:12 am
Forum: E-Vehicles General Discussion
Topic: Wire for wiring halls to Xlyte Hub?
Replies: 13
Views: 922

Re: Wire for wiring halls to Xlyte Hub?

Sorry for the delayed reply, been busy with new house-related stuff over the holidays. As Neil says, we spoke on the 'phone a couple of days ago about this. I bought some of this thin PTFE wire for Halls a couple of years ago and have found it to be really good. It's a pain to strip, unless you have...
by Jeremy Harris
Dec 29, 2012 4:42 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

gate drive should have a zener to protect the gate. whatta lotta work to imitate the output mosfets. then place it in series. No need for the zener at all, if the right resistor values are used. Just an extra component that adds nothing useful. The FETs need more than about 6 or 7 V on the gate to ...
by Jeremy Harris
Dec 26, 2012 4:46 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

so this is 0.7w compared to 3.6w. correct? so this should be no problem. Yes, no problem if you are going to mount them on an alloy bar as a heat sink. My rule of thumb for TO220 FETs with no heat sink, mounted inside a sealed case (which is how mine are mounted), is no more than about 1W, but if y...
by Jeremy Harris
Dec 26, 2012 4:30 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

thanks jeremy for doing the math for me :) those fets will be installed on the inside of a 12fet infineon controller. do you know the heat dissipation of the installed 4110s? if this is much higher then 2w i can life with it ;) A good general rule of thumb for these controllers is that the FET diss...
by Jeremy Harris
Dec 26, 2012 4:14 pm
Forum: General Discussion
Topic: Dear America,
Replies: 322
Views: 15373

Re: Dear America,

I went there and miles deleted my posts. :) Did you get an actual notice it was deleted? If you hit preview or save draft instead of submit it won't be up there. I see you've quoted a comment by etriker (personally I find very little of interest in his posts so have him permanently on ignore). For ...
by Jeremy Harris
Dec 26, 2012 4:06 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

It's best to use the data sheet maximum figures, rather than the typical, just to be safe, so 3077s are really 3.3mohms, 4110s are really 4.5mohms and 4310s are 7mohms. If you had 4 paralleled 4310s, then the total on resistance would be around 1.75mohms max. At 40A the power loss in the FETs would ...
by Jeremy Harris
Dec 26, 2012 1:12 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

wonderful. i already thought that as well. those circuits don't draw any current when not connected, so only as soon as you engage the switch, the current flows, and you need a small switch only, as current to feed the circuit is super small. i will just have to adopt the circuit to fb4310. i hope ...
by Jeremy Harris
Dec 26, 2012 1:07 pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 20
Views: 4587

Re: Automatic anti spark circuit

I described my way of doing this here: http://endless-sphere.com/forums/viewtopic.php?f=3&t=40142#p586436 I found that even for low current use there was a big benefit in using several FETs in paralell, just to keep the temperature down in the FETs. My first version used a single IRFB4110 on a bike ...
by Jeremy Harris
Dec 26, 2012 1:00 pm
Forum: Battery Technology
Topic: Nickel batteries parallel charging
Replies: 13
Views: 1052

Re: Nickel batteries parallel charging

I had a massive fire and explosion from accidentally charging some NiMH cells in parallel, at a charge rate that was only about 0.1 or 0.2C, IIRC. I'd thought (wrongly) that at a low charge rate this would be safe, but it nearly burned my house down. There is a difference. You were charging at leas...
by Jeremy Harris
Dec 26, 2012 12:55 pm
Forum: E-Bike Technical
Topic: looking for a battery power switch
Replies: 33
Views: 2561

Re: looking for a battery power switch

The circuit in the thread below does this, and manages the capacitor inrush current when switched on. The isolation when the switch is off is very good, I couldn't measure any current at all flowing when switched off and two of my bikes have this type of switch as the only power switch, and I leave ...
by Jeremy Harris
Dec 26, 2012 12:48 pm
Forum: Battery Technology
Topic: Nickel batteries parallel charging
Replies: 13
Views: 1052

Re: Nickel batteries parallel charging

I had a massive fire and explosion from accidentally charging some NiMH cells in parallel, at a charge rate that was only about 0.1 or 0.2C, IIRC. I'd thought (wrongly) that at a low charge rate this would be safe, but it nearly burned my house down. Are you sure that the charger in question really ...
by Jeremy Harris
Dec 26, 2012 5:41 am
Forum: E-Bike Technical
Topic: Another Lebowski controller
Replies: 38
Views: 3002

Re: Another Lebowski controller

Jeremy what are you planing to use the big controller for? And you have 3 of the big mosfets? I think I have one left thats ok lol. My only problem is the VMM-650 mosfets are discontinued.... If you blow one what do you do? The plan is to build a controller to run a paralleled pair of Colossus 80-1...
by Jeremy Harris
Dec 25, 2012 4:31 pm
Forum: General Discussion
Topic: Merry Christmas to all!!!!
Replies: 196
Views: 3900

Re: Merry Christmas to you all!

Merry Christmas to all, and the very best wishes for the coming New Year. The shear size and multicultural membership of ES, with everyone around the globe that's here sharing a common interest in pollution free, low impact, transport, is heartening in this age where so few seem to care much about t...
by Jeremy Harris
Dec 25, 2012 4:27 pm
Forum: E-Bike Technical
Topic: motor dosent run
Replies: 42
Views: 2163

Re: motor dosent run

It may be that the voltage drops with the flat battery as soon as there is any load, causing either the controller low voltage cut out to activate os perhaps the battery BMS low voltage cut out to operate. Was the meter connected all the time, or only when you were testing the battery voltage with n...
by Jeremy Harris
Dec 25, 2012 9:08 am
Forum: E-Bike General Discussion
Topic: European Dealers
Replies: 12
Views: 466

Re: European Dealers

I mean the plastic holders that i could click the cells into. As already said, forget this idea, it will give no end of trouble and isn't practical for the sort of current that an ebike battery has to handle. Either get the cells welded together with nickel tabs (there's a long thread here on a che...
by Jeremy Harris
Dec 25, 2012 3:52 am
Forum: E-Bike General Discussion
Topic: European Dealers
Replies: 12
Views: 466

Re: European Dealers

I have the bike, so it isn't so much motors and conversion kits i need. I need to build the battery out of the scrap laptop parts, so i am looking at a project like this http://www.instructables.com/id/Make-an-inexpensive-Lithium-Ion-Battery-Pack/ I need bits like battery holders and the circuit bo...
by Jeremy Harris
Dec 24, 2012 12:44 pm
Forum: General Discussion
Topic: What are you doing for amageddon?
Replies: 26
Views: 1105

Re: What are you doing for amageddon?

Salty, you sophisticated, educated person that you are! I had to google zymology! I think we could all use a good Zymology thread about now!! I know my Grandmother was able to make wine in the cellar that would flare when you put a match to it. The literature says it is impossible to ferment to suc...
by Jeremy Harris
Dec 24, 2012 12:30 pm
Forum: E-Bike Technical
Topic: Another Lebowski controller
Replies: 38
Views: 3002

Re: Another Lebowski controller

Sorry, missed that question, Rick. From a quick read of the data sheet it looks like the drive capability of the 2186 is pretty much up to driving some pretty big FETs directly, probably even the massive VMM 650 HiperFETs I have for the big controller I'm planning. Here's what the populated boards l...
by Jeremy Harris
Dec 24, 2012 7:13 am
Forum: E-Bike Technical
Topic: Turnigy Wattmeter clock does not work with less than 1 amp
Replies: 8
Views: 466

Re: Turnigy Wattmeter clock does not work with less than 1 a

Anyway, regardless of inner working limitation it's still a defect. The least they could do is to document it. Defect implies that the product is faulty. The reality is that it's a product design limitation. I agree that documentation would be good, but I've yet to see decent and accurate documenta...
by Jeremy Harris
Dec 24, 2012 6:04 am
Forum: E-Bike General Discussion
Topic: Does More Power Sometimes Decrease Rider Satisfaction?
Replies: 39
Views: 4109

Re: Does More Power Sometimes Decrease Rider Satisfaction?

A good algorithm would be one that encouraged the rider to exercise more rather than motivating them to minimise effort. This is key to the success of a lightweight assist system, rather than an out and out electric moped or motorcycle, I think. The best system I've ridden is the Panasonic bottom b...
by Jeremy Harris
Dec 24, 2012 5:09 am
Forum: E-Bike General Discussion
Topic: European Dealers
Replies: 12
Views: 466

Re: European Dealers

Hi all, I have been searching the forum for two days now and reading the existing dealers thread, but it is a bit of a jumble, I am unable to locate dealers in mainland western Europe, specifically the Benelux or Germany. Is this an international forum or are there members that could point me in th...
by Jeremy Harris
Dec 24, 2012 4:09 am
Forum: E-Bike Technical
Topic: Turnigy Wattmeter clock does not work with less than 1 amp
Replies: 8
Views: 466

Re: Turnigy Wattmeter clock does not work with less than 1 a

I doubt it. Less than 1 amp is still current. The bright side is that the A, V, W, Ah, Wh, Wp and Vm are still being recorded correctly, as far as I can tell. For that to work the internal clock must be running. It's just not getting updated for the display. Glad to know that yours behaves the same...
by Jeremy Harris
Dec 23, 2012 9:06 am
Forum: E-Bike General Discussion
Topic: Possible to build an electric foldable bike?
Replies: 7
Views: 811

Re: Possible to build an electric foldable bike?

If you go for one of the cheap programmable controllers then you can build the bike, test it, and then reprogramme the controller to get the speed to the legal limit (max speed, as a percentage, is programmable, as well as the current limit). This means you can be sure that your ebike won't exceed 2...
by Jeremy Harris
Dec 23, 2012 8:25 am
Forum: E-Bike General Discussion
Topic: Possible to build an electric foldable bike?
Replies: 7
Views: 811

Re: Possible to build an electric foldable bike?

Thanks for the info! From the website, it seems like the smallest power output is still 250 watts which exceed Singapore Rules. In order to use an electric bicycle here, your bike need to be certified by local regulator (otherwise you will be fined). Singapore is a "fine" country. You will get fine...
by Jeremy Harris
Dec 23, 2012 3:39 am
Forum: Battery Technology
Topic: Bottom balancing?
Replies: 479
Views: 15661

Re: Bottom balancing?

We've done this EVTV rubbish to death here, several times. The bloke that heads up that show is technically naive (that's being polite about it) and clearly has no real understanding of how the cells he is using work and why SoC can only be determined accurately when all cells are charged to a set c...