Search found 1070 matches

by Knuckles
Jun 03, 2013 3:20 am
Forum: Battery Technology
Topic: Fechter's Capacitor Coupled Cell Balancer
Replies: 183
Views: 12390

Re: Fechter's Capacitor Coupled Cell Balancer

I got the idea from this source ... http://www.celnav.de/hv/hv9.htm (scroll thru) I expect a three phase 'generator' at 20-50 kHz would be good. At higher frequencies the system is more efficient and smaller caps will work for a given power input. Individual battery cells act as capacitors so the ca...
by Knuckles
Jun 02, 2013 6:14 pm
Forum: Battery Technology
Topic: Fechter's Capacitor Coupled Cell Balancer
Replies: 183
Views: 12390

Re: Fechter's Capacitor Coupled Cell Balancer

Maybe something like this ...

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by Knuckles
Dec 09, 2011 6:02 pm
Forum: E-pic Topics
Topic: A Summary Letter for the ES Community
Replies: 157
Views: 33650

Re: A Summary Letter for the ES Community

First Rule of "Fight Club"?
by Knuckles
Dec 09, 2011 4:58 pm
Forum: E-pic Topics
Topic: A Summary Letter for the ES Community
Replies: 157
Views: 33650

Re: A Summary Letter for the ES Community

Gosh, leave for a little while and all HELL breaks loose! (I never really “left” ES, just been busy with “stuff”) I am really GLAD that Justin is now the “Custodian” of ES. It is the BEST thing that could have happened. I really hope he embraces his “Stewardship” and proudly places his BANNER on ES....
by Knuckles
Dec 08, 2011 10:29 pm
Forum: E-pic Topics
Topic: A Summary Letter for the ES Community
Replies: 157
Views: 33650

Re: A Summary Letter for the ES Community

There's only ONE BANNER I'd like to see on ES ....

www.ebikes.ca


8)
by Knuckles
Jan 31, 2011 5:55 pm
Forum: Battery Technology
Topic: Moronically Simple LVC Circuit
Replies: 11
Views: 662

Re: Moronically Simple LVC Circuit

Dirt cheap switching diodes ... at 25C ... 0.1 ma - 0.5v drop, 1.0 ma - 0.6v drop, 5.0 ma -0.7v drop When the key switch is "on" the I(f) is between 10 and 15 ma for EVERY primary emitting diode (the C-E is saturated) But as a cell V drops the primary C-E voltage decreases to 0.1v and the current to...
by Knuckles
Jan 31, 2011 4:53 pm
Forum: Battery Technology
Topic: Moronically Simple LVC Circuit
Replies: 11
Views: 662

Re: Moronically Simple LVC Circuit

The worst case warm weather low cell voltage detect could be around 0.6 + 0.6 + 0.9 + 0.5 = 2.6V, probably OK, and the worst case cold weather low cell voltage detect could be around 0.7 + 0.7 +1.4V + 0.7 = 3.5V, no use whatsoever, as it will trigger when the cells are still well charged.Jeremy I c...
by Knuckles
Jan 31, 2011 4:14 pm
Forum: Battery Technology
Topic: Moronically Simple LVC Circuit
Replies: 11
Views: 662

Re: Moronically Simple LVC Circuit

ergo "moronically" simple ...

but a LVC at 2v and room temp is better than no LVC at all.

:)
by Knuckles
Jan 31, 2011 3:39 pm
Forum: Battery Technology
Topic: Moronically Simple LVC Circuit
Replies: 11
Views: 662

Moronically Simple LVC Circuit

Moronically Simple LVC Circuit
If any cell goes low the +12v ebrake circuit kicks in
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http://search.digikey.com/scripts/DkSea ... -1370-5-ND

***
by Knuckles
Nov 26, 2010 12:05 am
Forum: Battery Technology
Topic: The Hand of GOD
Replies: 14
Views: 970

The Hand of GOD

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by Knuckles
Aug 24, 2010 6:12 pm
Forum: Battery Technology
Topic: Switched capacitor balancer tests
Replies: 48
Views: 6007

Re: Switched capacitor balancer tests

And it can also be "double capped" if you want to get really nutty ...

Image

reference
by Knuckles
Aug 24, 2010 6:00 pm
Forum: E-Bike Technical
Topic: Infineon has REGEN BRAKING (and more)
Replies: 249
Views: 41718

Re: Infineon has REGEN BRAKING (and more)

XieChang Controller Regen (All Models): 1) Regen DOES NOT bring wheel to complete stop. 2) Regen has an upper (programmable) voltage limit (HVC or high voltage cut-off). 3) You can't "regen" more current than your battery chemistry/size can accept at the HVC. 4) Front wheel Direct Drive motor is bes...
by Knuckles
Aug 22, 2010 4:12 pm
Forum: Battery Technology
Topic: Switched capacitor balancer tests
Replies: 48
Views: 6007

Re: Switched capacitor balancer tests

The standard paper on switched cap balancers is: C. Pascual and P. T. Krein, "Switched capacitor system for automatic series battery equalization." Most links for it are dead, but I got it off the Wayback Machine. Or see US patent 5710504 As far as the suitability of switched cap balancers for larg...
by Knuckles
Aug 22, 2010 4:09 pm
Forum: Battery Technology
Topic: Switched capacitor balancer tests
Replies: 48
Views: 6007

Re: Switched capacitor balancer tests

Knuckles, your drawing gets the basic idea, the gate drive scheme won't work (particularly for larger packs). Most switched cap balancers use a P channel high side fet and an N channel low side fet. The gate drives need to be isolated from each other, otherwise you quickly run out of Vgs thresholds...
by Knuckles
Aug 08, 2010 7:54 am
Forum: E-Bike Technical
Topic: 150v xie cheng failure thread
Replies: 8
Views: 644

Re: 150v xie cheng failure thread

All XieChang controller boards are designed for no more than 72 volts nominal. They can handle maybe 100 volts max before the need to "protect" the R10 and R11 resistors from overheating. In addition, the components of the switching circuit are themselves rated at about 100-120 volts max. Specifical...
by Knuckles
Jul 05, 2010 10:28 am
Forum: E-Bike Technical
Topic: **Important** reality check on motor, voltage, current etc.
Replies: 360
Views: 20242

Re: **Important** reality check on motor, voltage, current e

This thread just blew my controller! :D
by Knuckles
Jul 04, 2010 1:07 pm
Forum: E-Bike Reviews & Testing
Topic: ALL NEW 150V-30A XieChang CONTROLLER
Replies: 32
Views: 5696

Re: ALL NEW 150V-30A XieChang CONTROLLER

Finally ...

Image

High resolution original step-by-step pics here ...
http://98.131.176.65/endless-sphere/150V30A/?N=D

btw ... Contact Steveo if you want one ... He likes soldering. I HATE soldering.
I like design.

F-N-A

-Knuckles
by Knuckles
Jul 01, 2010 11:04 pm
Forum: E-Bike Reviews & Testing
Topic: ALL NEW 150V-30A XieChang CONTROLLER
Replies: 32
Views: 5696

Re: ALL NEW 150V-30A XieChang CONTROLLER

Knuckles- For a given motor do you know what the current through the FETs has in common for the following examples? 50v 75amps 100v 37.5amps 150v 25amps It's all exactly the same current loading through the FETs. The difference is simply that the 150v rated FETs will be making about 3-4x the heat. ...
by Knuckles
Jul 01, 2010 10:00 pm
Forum: E-Bike Reviews & Testing
Topic: ALL NEW 150V-30A XieChang CONTROLLER
Replies: 32
Views: 5696

Re: ALL NEW 150V-30A XieChang CONTROLLER

DANG!

Still testing! Help anybody?

I hate soldering. I LOVE theory. :roll:

Seriously ... I welcome fellow scientists.

I've been so busy with work (like real job work).
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by Knuckles
Jun 20, 2010 3:20 pm
Forum: General Discussion
Topic: Now This Really Sucks
Replies: 134
Views: 7898

Re: Now This Really Sucks

Interesting Math … When engineers report quantities of a gas like methane they are generally referring to Standard Temperature and Pressure (STP), which is room temperature and 1 atmospheric pressure. Engineers can convert the STP gas value to another gas value at a different temperature and p...
by Knuckles
Jun 20, 2010 9:09 am
Forum: General Discussion
Topic: Now This Really Sucks
Replies: 134
Views: 7898

Re: Now This Really Sucks

The Dwarves dug too greedily and too deep. You know what they awoke in the darkness of Khazad-dum... shadow and flame.

— Saruman, The Lord of the Rings

The Well from Hell
by Knuckles
Jun 20, 2010 7:36 am
Forum: General Discussion
Topic: Now This Really Sucks
Replies: 134
Views: 7898

Re: Now This Really Sucks

A new article out June 18 might inadvertently add some weight to Richard Hoagland's claim/theory/rumor of a methane bubble under the sea waiting to explode on some Armageddon-type level. Hoagland warns of Gas Bubble and Tsunami of Biblical Proportions. According to oceanographer John Kessler the met...