Search found 43 matches

by ecotech
Dec 03 2016 5:26am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 44285

Re: PM Motor theory - formulae etc.

Yes harmonics are not good, what's your view on torque ripple I see so many people trying to minimize it but you decrease motor performance by doing that.
by ecotech
Dec 02 2016 5:43am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 44285

Re: PM Motor theory - formulae etc.

Yes sine wave is good because it has a constant change of flux so induction is not too big, this is really good for efficiency. There are some researches that say a sine wave is not optimal though because when the edges of the magnet pass the copper wire there is a sudden change of force, you can't ...
by ecotech
Dec 02 2016 3:37am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 44285

Re: PM Motor theory - formulae etc.

Actually a sin wave is not optimal for any motors , more like a step charged sin wave but I design my motors to take in whatever wave. you need sin wave if you have iron losses in which case you have a not so good design also it's needed for low torque ripple but why have low torque ripple? ICE engi...
by ecotech
Dec 01 2016 12:44pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1649
Views: 236338

Re: Thread for new battery breakthrough PR releases

Well I have a problem of sourcing the weed otherwise I could be making those batteries of robert murray smith. :mrgreen: :mrgreen:

Edit: Added weed faces.
by ecotech
Nov 29 2016 5:36am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1649
Views: 236338

Re: Thread for new battery breakthrough PR releases

The problem will either be either buying the graphite or grafoil or if you use natural templates a.k.a. RMS's weed :mrgreen: :lol: to carbonize them the problem is with the equipment, vacuum furnaces cost 100s of k, then again if you use metals in anode/cathode you also need a vacuum furnace to make...
by ecotech
Nov 27 2016 4:24pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1649
Views: 236338

Re: Thread for new battery breakthrough PR releases

The reason is that the electrodes gets raped in every charge and discharge in simple terms. Toyota keeps things to herself, you can look at the patent wars between US and Japan, just funny, also it deters anyone from patenting anything.
by ecotech
Nov 24 2016 5:25am
Forum: Battery Technology
Topic: offer of A123 20Ah from powermartplus
Replies: 11
Views: 1341

Re: offer of A123 20Ah from powermartplus

Alkaline means basic
by ecotech
Nov 21 2016 5:17am
Forum: Motor Technology
Topic: Seeking Motor Designer
Replies: 24
Views: 2208

Re: Seeking Motor Designer

I use ansoft maxwell. You can find motor design from researches from scihub.
by ecotech
Nov 20 2016 3:12pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24327

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Do you buy the chemical ready made or do you have furnaces and make the stuff yourselves? Wet method is troublesome. Do you use carbonate solvent and hexafluorophosphate for the electrolyte ? Triflates are expensive. I haven't read much on titanates I discarded it because it has low energy density a...
by ecotech
Nov 20 2016 11:58am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24327

Re: OSHW TO247 IGBT watercooled laminated half-bridge

What do you mean what you say your company , you own it or work for it? And why do you make lithium titanate batteries? You don't like cobalt or phosphates?
by ecotech
Nov 20 2016 11:57am
Forum: Motor Technology
Topic: Seeking Motor Designer
Replies: 24
Views: 2208

Re: Seeking Motor Designer

Will you sell the bike or what?
by ecotech
Nov 19 2016 7:25am
Forum: Motor Technology
Topic: ES DIY Motor Challenge
Replies: 328
Views: 122740

Re: ES DIY Motor Challenge

Ferromagnets concetrate the flux somewhere by the principle of superposition, infinetisimal current of loops in higher magnetic permeability materials cancel and amplify the resulted forces by the magnetic field in specific regions.

For bikes and bicycles how much torque and power is the optimal?
by ecotech
Nov 16 2016 8:51am
Forum: Motor Technology
Topic: ES DIY Motor Challenge
Replies: 328
Views: 122740

Re: ES DIY Motor Challenge

I find it easier to not use any iron at all but what happens is the case of the motor must have small magnetic coercivity otherwise the flux goes in the case instead of the copper wire.
by ecotech
Nov 14 2016 6:27pm
Forum: EV Business World
Topic: High end motors - priced out of existence?
Replies: 45
Views: 11443

Re: High end motors - priced out of existence?

Oh ok, how many rpm do these motors achieve then?
by ecotech
Nov 14 2016 3:54pm
Forum: Motor Technology
Topic: ES DIY Motor Challenge
Replies: 328
Views: 122740

Re: ES DIY Motor Challenge

How does this motor you say look like?
by ecotech
Nov 13 2016 5:33pm
Forum: EV Business World
Topic: High end motors - priced out of existence?
Replies: 45
Views: 11443

Re: High end motors - priced out of existence?

I've been working out computers models in ansoft maxwell, the inductance was something like 600nH which is 0.6uH, I've changed the model now to increase the inductance, how much inductance is needed for common controllers? Why do you say that high torque motors have low inductance? The torque is mul...
by ecotech
Nov 13 2016 3:25am
Forum: EV Business World
Topic: High end motors - priced out of existence?
Replies: 45
Views: 11443

Re: High end motors - priced out of existence?

Do AC inverters need inductance to work too? For induction motors. I have one with nH total inductance.
by ecotech
Nov 12 2016 4:58pm
Forum: EV Business World
Topic: High end motors - priced out of existence?
Replies: 45
Views: 11443

Re: High end motors - priced out of existence?

Can you explain to me why can't inverters run low inductance coils? It should be exactly the opposite from my understanding but I don't know much about electronics only physics.