Search found 999 matches

by ZapPat
Oct 25 2011 6:11am
Forum: E-Bike Technical
Topic: How much of an issue is battery loop inductance?
Replies: 24
Views: 2801

Re: How much of an issue is battery loop inductance?

You guys are over my head, so I'm playing catch up here. None of my bike have compact battery packs, and I really want the freedom to spread them out even more. It sounds like I definitely need extra caps, some electolytics and some rail caps like BigMoose mentioned here that squash voltage spikes....
by ZapPat
Aug 30 2011 2:55pm
Forum: E-Bike Technical
Topic: IRFB3006 vs IRLB3036
Replies: 5
Views: 799

Re: IRFB3006 vs IRLB3036

Use KaptonMT instead of the regular kapton (much better thermal conductivity), and try to avoid the pre-adhesive types if you really want maximum performance (just use minimal thermal grease on both sides as LHelge suggests above).
by ZapPat
Aug 03 2011 5:44am
Forum: E-Bike Technical
Topic: Dual Controller, Single Stator ?
Replies: 14
Views: 1550

Re: Dual Controller, Single Stator ?

To finally answer the OP's question, yes you could use two sensored controllers together on one motor. HOWEVER, it is critical that you add in some lowish amount of inductance on each controller's outputs to partially isolate them from each other. Thus this would require six inductors, which serve t...
by ZapPat
Jul 11 2011 6:18am
Forum: E-Bike Technical
Topic: Are 4310Z fets any good?
Replies: 11
Views: 1196

Re: Are 4310Z fets any good? --> Great for 100V people!

As people have pointed out, the irfb4310 will not tolerate as much current as the irfb4110, but... I recently noticed something *better* about the 4310 while looking over its datasheet and then comparing it to the 4110, of particular interest to all you crazy extreme "overvolters" out there: The 431...
by ZapPat
Jul 03 2011 12:08pm
Forum: E-Bike Technical
Topic: Timing Adjustment Tool
Replies: 461
Views: 64780

Re: Timing Adjustment Tool -Road testing

Are you monitoring the battery current during experiments? Not yet.... #2 It never told me max speed after a run on the dyno does this meen its not getting a clean signal? You are not getting the motor past the threshold speed? (see userguide), otherwise Not sure why this would happen. If the hall ...
by ZapPat
Jul 01 2011 7:42am
Forum: E-Bike Technical
Topic: Electric power trike PDQ - Throttle HELP!
Replies: 3
Views: 812

Re: Electric power trike PDQ - Throttle HELP!

Best bet would be to replace the linear hall sensor from the throttle (the throttle housing is not physically broken is it?). Search here for replacing a throttle hall sensor, there is a short thread with compatible part numbers and they are pretty cheap too.

Good luck
by ZapPat
Jun 25 2011 8:23am
Forum: E-Bike Technical
Topic: New Crystalyte Motor series (HT35 / HS35 and HT24 / HS24)
Replies: 1395
Views: 210387

Re: New Crystalyte Motor series (HT35 / HS35 and HT24 / HS24

When I noticed a light scraping noise on one of the newly potted motors, I got curious and opened it up again because I thought too much epoxy potting had been applied and was rubbing against the side cover. What I found was this ---> Damaged Winding.JPG :shock: Maybe that could have been a cause f...
by ZapPat
Jun 24 2011 8:31am
Forum: E-Bike Technical
Topic: chinese-ST 6 mosfet 24v-250w controller
Replies: 35
Views: 9035

Re: chinese-ST 6 mosfet 24v-250w controller

It's probably a *bad* idea to try that small controller out with that big motor, zEEz. The motor probably has quite low resistance/inductance since it is large, and so would generate much higher phase currents than a small hub - possibly destroying your controller's FETs.
by ZapPat
Mar 17 2011 11:03am
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 24643

Re: Doc EXTREME 36 FETS controller

Pat, It's always nice to have someone else look over the math. I'm not sure if this was my primary source during that previous discussion, but Fairchild Semi has a nice app note on making these calculations: http://www.fairchildsemi.com/an/AN/AN-6005.pdf I'm really doing it for my own education sin...
by ZapPat
Mar 16 2011 12:55pm
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 24643

Re: Doc EXTREME 36 FETS controller

I plan on soldering each 6 fets group together on a thin 20mil thick copper sheet to better share the current between those and also to share the heat. That should also help increasing the thermal transfer from the mosfets to the silpad since the total area for all 6 fets will change by around 2.5X...
by ZapPat
Mar 15 2011 3:01pm
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 24643

Re: Doc EXTREME 36 FETS controller

- Equivalent junction-to-sink resistance for 18 FETs is now 2.86C/W / 18 = 0.159C/W It seems to me that there are only 6 FETs in parallel sharing a thermal path at any time on the PWM'd phase, not 18. So that number would be 3 times higher, about 0.477oC/W per FET group, using those *good* silpads ...
by ZapPat
Feb 26 2011 6:17pm
Forum: E-Bike Technical
Topic: A whole new level of spun axles - what 10KW does to an X5
Replies: 216
Views: 20225

Re: A whole new level of spun axles - what 10KW does to an X

Oh yea - and everybody is corrupt so it makes business a lot easier. No papers? Oh, allow me to pay my no papers ticket of $50.... thank you sir. Only worry is those crafty drug lords... don't want them to find out how profitable the ebike business is or they might try and horn in. -methods Sounds ...
by ZapPat
Feb 26 2011 9:29am
Forum: Motor Technology
Topic: DIY: asynchronous BLDC motor controller
Replies: 4
Views: 1672

Re: DIY: asynchronous BLDC motor controller

Hi. I'm designing a 10kW BLDC controller for my electric scooter conversion. Currently I'm using BLDC motor with hall sensors on all three phases, but there are problems with timing - the sensors are not ideally aligned and I get a timing error that produces 1kW of waste energy. So now I'm going fo...
by ZapPat
Feb 25 2011 7:47pm
Forum: E-Bike Technical
Topic: New Crystalyte Motor series (HT35 / HS35 and HT24 / HS24)
Replies: 1395
Views: 210387

Re: New Crystalyte Motor series (HT35 / HS35 and HT24 / HS24

Doc, Just to get this absolutely straight: Torque = phase current x winding turns Altering the way the windings are connected does not change this at all. Wye and delta will both give exactly the same torque at the same phase current. Jeremy Maybe I'm confused but this sounds odd to me. I would exp...
by ZapPat
Feb 24 2011 8:47am
Forum: E-Bike Technical
Topic: Timing Adjustment Tool
Replies: 461
Views: 64780

Re: Timing Adjustment Tool -Added throttle position mapping

-one fairly odd thing though, is down a hill at 58kph (only drawing about 200w on full throttle cos its near the unloaded motor speed) when i lift off the throttle, it immediately regens about 300w back into the battery (no braking on regen enabled) this has never happened before, and is obviously ...
by ZapPat
Feb 23 2011 7:23am
Forum: E-Bike Technical
Topic: Timing Adjustment Tool
Replies: 461
Views: 64780

Re: Timing Adjustment Tool -Added throttle position mapping

...and is there any software filtering? Many modern brushless motor control oriented MCU's have a configurable digital filter integrated in the three inputs used for hall sensors. If you MCU has this feature it needs to be activated through one of it's registers. Other than this you could also just...
by ZapPat
Feb 22 2011 11:41am
Forum: E-Bike Technical
Topic: Belleville or split lock washer for To-220 mosfet
Replies: 8
Views: 1110

Re: Belleville or split lock washer for To-220 mosfet

Hey Doc, I can't tell you anything about those cheap bellevilles I found since I've never tried them - but they are real cheap so I would order some to try if I were you (plus it sounds like you can get free shipping too, lucky you!). You can also stack them in different ways to get either more spri...
by ZapPat
Feb 22 2011 9:11am
Forum: E-Bike Technical
Topic: Mac 500w motor issues
Replies: 31
Views: 3162

Re: Mac 500w motor issues

I would be *very* interested in one of those big motors with the new gears, cell man! The gear issues when used with higher phase currents have been holding me back from regular geared motors so far, so I would love to see a better option for us ebike "overclockers" out there. Any idea of the approx...
by ZapPat
Feb 22 2011 8:05am
Forum: E-Bike Technical
Topic: Belleville or split lock washer for To-220 mosfet
Replies: 8
Views: 1110

Re: Belleville or split lock washer for To-220 mosfet

It looks like McMaster part # 93501A005 (reg. steel) or 90895A005 (stainless - 4 times more expensive) would be what you might want, Doc. The problem with Mcmaster Carr is that they won't ship to a Canadian address unless you have a business account, but the best part is they don't mention that deta...
by ZapPat
Feb 17 2011 6:02pm
Forum: E-Bike Technical
Topic: BLDC Brain
Replies: 59
Views: 7628

Re: BLDC Brain

Good morning, Pat. Thanks for trying. I was hoping for an explanation of how the circuits actually work but we are not getting there. I'll have to figure it out when I have time. In order to write control software for this it must be correctly understood at a pretty low level. Hi Alan, both you and...
by ZapPat
Feb 17 2011 7:15am
Forum: E-Bike Technical
Topic: BLDC Brain
Replies: 59
Views: 7628

Re: BLDC Brain

Hi Pat. Lots of good information. Thanks. I did read your long posts and they don't appear to address my question about the voltage boost mechanism. [...] PWM into a motor is a voltage bucking operation. Where is the voltage boost in the normal PWM commutation cycle? Study the PWM buck circuit goin...
by ZapPat
Feb 16 2011 1:30pm
Forum: E-Bike Technical
Topic: BLDC Brain
Replies: 59
Views: 7628

Re: BLDC Brain

I could be all wet here, but when I reduce throttle below the PWM level required for acceleration I get little to no regeneration. It just coasts. If only the high side FETs are switched then controlling only drive currents are possible, any duty cycle less than this will result in no current flowi...
by ZapPat
Feb 16 2011 11:46am
Forum: E-Bike Technical
Topic: BLDC Brain
Replies: 59
Views: 7628

Re: BLDC Brain

Great descriptions, Pat. It seems to me that during regen braking using the diode techique that max braking would occur at or near 50% PWM which maximizes the voltage up conversion effect? I also like the idea of an analog ebraking control. Perhaps a separate brake lever or smaller trigger since hy...
by ZapPat
Feb 16 2011 8:24am
Forum: E-Bike Technical
Topic: BLDC Brain
Replies: 59
Views: 7628

Re: BLDC Brain - Regen explained a bit

Since there still seems to be many questions on how a brushless controller does regen, I'll try to help out and explain it as simply as I can. Hopefully it won't sound too much like "rocket science" ... :roll: *edit*: Others have posted better regen explanations since I started writing this, but I'l...
by ZapPat
Feb 05 2011 3:54pm
Forum: E-Bike Technical
Topic: IRLB3036PBF 1.9mohm mosfet vs the IRF3205
Replies: 33
Views: 3427

Re: IRLB3036PBF 1.9mohm mosfet vs the IRF3205

Fair enough Luke, I know your day job is working on equipment cooling so I won't argue with you. Instead, I will continue my reading and research on the subject and eventually I might well order a few of the little buggers to build an alternative power output stage for my controller to see what they...