Search found 600 matches

by BigMouse
Tue, 31 Jan 2012, 19:53
Forum: General EV Discussion
Topic: Making EVs commercially in AU: If not NOW, When?
Replies: 94
Views: 8528

Making EVs commercially in AU: If not NOW, When?

It seems to me that the Australian government is painfully inconsistent with its policy. It introduces a "carbon tax" under the guise of reducing emmissions, but exempts fuel for motor vehicles from the tax. At the same time, they government offers no incentive at all to citizens to buy "green" cars...
by BigMouse
Sat, 28 Jan 2012, 23:25
Forum: Batteries, charging, management and monitoring
Topic: Small battery pack for controller testing
Replies: 11
Views: 2299

Small battery pack for controller testing

Some quick pics of the current state of my testing battery pack: BMS installed, batteries temporarily connected in series so that BMS can be tested on the full string. http://dl.dropbox.com/u/301235/EV%20Project/IMG_20120128_164231.jpg It works! At least without any interferrence. Looking forward to...
by BigMouse
Thu, 19 Jan 2012, 22:25
Forum: Members Machines
Topic: Richo's AC Handi Sports
Replies: 84
Views: 10672

Richo's AC Handi Sports

Awesome! The mighty car mods guys will love this! Marty has just finished swapping a sirion engine/transmission into his Cuore (same as your Handi). Very cool car. He swears he'll let me convert one for him some day. What are you going to do for a controller?
by BigMouse
Mon, 16 Jan 2012, 17:55
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 337980

Weber and Coulomb's MX-5

As was mentioned before, crimp connections are the most reliable. In both automotive and aviation applications, crimps are always used. Rather than using terminal strips or spades/bullets, maybe use a multi-pin connector with crimp terminals. Here are a few examples, available with 2-12 pins: 15A pl...
by BigMouse
Thu, 20 Oct 2011, 01:31
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Latest progress on my controller.

YouTube video

I have all the bits to put my battery management system together now too, after a bit of a wait for parts to arrive from overseas. Now I just have to assemble a couple hundred boards to make it work. I really need a reflow oven.
by BigMouse
Sun, 25 Sep 2011, 06:23
Forum: Batteries, charging, management and monitoring
Topic: Small battery pack for controller testing
Replies: 11
Views: 2299

Small battery pack for controller testing

I paid about $2.20 per cell, and had them assembled in 3s2p bricks that I used to build up the larger bricks you see in the pic. Got them from a seller on eBay. They're only 1ah APR118650M1A cells. The datasheet says they can do 30C continuous and 60C intermittently. Judging by the fact that two pai...
by BigMouse
Fri, 23 Sep 2011, 01:18
Forum: Batteries, charging, management and monitoring
Topic: Small battery pack for controller testing
Replies: 11
Views: 2299

Small battery pack for controller testing

I'm also very impressed you turned you meter off http://forums.aeva.asn.au/smileys/smiley10.gif That meter beeps at me if I leave it on more than 15 minutes. It's very annoying, so it gets turned off. That said, the rest of my meters get turned off too, even though they don't pester me about being ...
by BigMouse
Thu, 22 Sep 2011, 05:46
Forum: Batteries, charging, management and monitoring
Topic: Small battery pack for controller testing
Replies: 11
Views: 2299

Small battery pack for controller testing

Hey guys, Just posting this up because it might be of interest to the group. http://dl.dropbox.com/u/301235/EV%20Project/2011-09-21%2023.15.16.jpg There are 392 18650 "A123" cells in this pack, 98S 4P. I say "A123" because these are from eBay (China) and I can't be sure (they were advertised as "gen...
by BigMouse
Sat, 25 Jun 2011, 05:54
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

I notice that ecomodder's Paul and Sabrina have embarked on a 3 Phase Motor Controller. There maybe some useful ideas on their blog. The isolated supply for the high-side Gate drivers is simple and effective. Their gate drive supply looks quite similar to the design I came up with. I'm pretty happy...
by BigMouse
Fri, 24 Jun 2011, 14:15
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Example: say you're trying to regulate 20rpm slip speed with a motor speed of 1rpm, if the controller thinks the motor is doing 1rpm or 2rpm (100% error in speed measurement) it makes hardly any difference to the actual slip you're applying, it will be either 20rpm or 19rpm. I'm curious, does the T...
by BigMouse
Thu, 23 Jun 2011, 19:40
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

(...)In another thread, I identified an IC that should make high resolution shaft sensing a $50 problem for 1000 PPR class sensing. I will try this IC in due course, but don't see any reason that it won't work nicely. Very interesting part you've found. The cost of implementing something like this ...
by BigMouse
Thu, 23 Jun 2011, 19:27
Forum: Electric motors and controllers
Topic: Shaft encoder IC
Replies: 2
Views: 1544

Shaft encoder IC

Followed the link from my thread over here. That's a very interesting little chip. The price is right too, if it's replacing a $1500 encoder. 1024 ppr (equivalent). One of these could easily be mounted inside the fan end cover of an ACIM if a small magnet is attached to the end of the shaft there. V...
by BigMouse
Thu, 23 Jun 2011, 17:10
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

The absolute value idea was just a way to relate battery current to motor current. (..) Think of it in power terms. At one 30th of rated motor speed and thus voltage, the current is close to 30 times LESS at the battery. Whilst being a bit more complicated, as coulomb says, it's similar to the buck...
by BigMouse
Thu, 23 Jun 2011, 16:19
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Good point about the motor windings storing energy. When you say that motor current is many times battery current at low speed, are you referring to actual rotor speed, or low frequency? My torque control method will depend on a direct (not nessecarily linear) relationship between motor torque and b...
by BigMouse
Thu, 23 Jun 2011, 05:42
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

You're probably right, I'll write my thinking and hopefully you guys can tell me if I'm making incorrect judgements and guide me in the right direction. Sum of currents in a 3-phase motor equals zero (for equal load in each phase). This is because at any given point in the rotation, currents are flo...
by BigMouse
Thu, 23 Jun 2011, 00:34
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Thanks for the info. The AVR I've got my eye on (and have been playing with) also has some code written for it, but unfortunately it doesn't seem to work with the latest version of the compiler/IDE it was written for. I have already invested in AVR hardware and programmers, plus my Uni uses AVRs in ...
by BigMouse
Tue, 21 Jun 2011, 05:26
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Can somebody identify or put me in touch with this "engine whisperer" woody mentioned? If he does have some inexpensive 3-phase motors I could pick up for testing, I'd be interested (assuming they have low voltage 220-240v windings).
by BigMouse
Sat, 18 Jun 2011, 00:22
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Thanks for the explanation. Just curious that you mention 2 current sensors. Are these on the motor phases? The VFDs I have used tend to have 3 sensors. This way they can sense fault conditions (Sum of currents in 3 phases should = 0) If there is an earth or winding fault, any current imbalance wou...
by BigMouse
Thu, 16 Jun 2011, 20:53
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Would you be able to describe the various parts of the drive? IGBT model and rating, microcontroller, firmware availability etc?. Sure, to some extent. The controller consists of a number of modules at this point: -IGBT Date drive power supply (SMPS-based on off-the-shelf components to keep cost do...
by BigMouse
Thu, 16 Jun 2011, 18:15
Forum: Electric motors and controllers
Topic: My homebuilt VFD progress
Replies: 141
Views: 14549

My homebuilt VFD progress

Hey guys,

As I mentioned in my intro post on the general discussion forum, I'm designing and building my own 3-phase motor controller. I've made some progress on it today and put a quick video up on youtube I thought I'd share. Enjoy.

http://www.youtube.com/watch?v=rnhwFFOgYAE
by BigMouse
Sun, 12 Jun 2011, 05:04
Forum: General EV Discussion
Topic: A quick intro, conversion plans...
Replies: 0
Views: 601

A quick intro, conversion plans...

Hey guys. Been lurking on this forum for a while and figured it's about time I introduced myself. Hi, I'm Vincent, nice to meet you http://forums.aeva.asn.au/smileys/smiley2.gif I am not exactly 'new' to EVs, as I've done one conversion before. It was a Mazda RX7 DC conversion ( photo ), back in the...
by BigMouse
Sat, 11 Jun 2011, 04:44
Forum: AEVA NSW Branch
Topic: Sydney Branch Meeting 14-6-11
Replies: 2
Views: 746

Sydney Branch Meeting 14-6-11

I'm planning on trying to make it up for this. Time to break into the EV community here in Oz.

I'm especially keen if the iMiev will be there!
by BigMouse
Thu, 07 Apr 2011, 03:03
Forum: For Sale/Wanted
Topic: For Sale - Electrolux - '92 Hilux Extracab
Replies: 28
Views: 2862

For Sale - Electrolux - '92 Hilux Extracab

Very cool. I was very tempted to pick this up, but unfortunately didn't have the means while it was for sale. Awesome to see that E30 as a possible EV candidate. I saw it on eBay while I was shopping for my E36 and was very tempted, but ended up picking up a 92 318is instead, also white, as my EV-to...
by BigMouse
Wed, 10 Nov 2010, 04:37
Forum: Electric motors and controllers
Topic: AC motors, amping it up. :P
Replies: 58
Views: 8890

AC motors, amping it up. :P

Along the lines of this thread, I am curious about something regarding overvolting. Assuming a 240v 50Hz motor, V/Hz = 240/50 = 4.8, correct? If I understand correctly, in order to maintain rated torque at 100hz, 480v would be required from the VFD. I assume that the V/Hz ratio is maintained (disreg...