Open Source Electric Supercharger

[SkitterSkotter]

This thread is so badass!! Nice work good sir! I'm excited to see the developments with this. The only issue I see thus far, and I know it has been addressed quite a bit so far, is if this can produce a decent amount of pressure. If you could get 4-8psi you are looking at a perfect set up. As far as instant power, it would be cool to throw a small motor to run off one of the wheels to charge a system...kind of KERNS style. Or maybe use a compasitor in place of some batteries like mazda is doing to run their electronics on their skyactive models.

[mid_life_crisis]

Originally Posted by SkitterSkotter

This thread is so badass!! Nice work good sir! I'm excited to see the developments with this. The only issue I see thus far, and I know it has been addressed quite a bit so far, is if this can produce a decent amount of pressure. If you could get 4-8psi you are looking at a perfect set up. As far as instant power, it would be cool to throw a small motor to run off one of the wheels to charge a system...kind of KERNS style. Or maybe use a compasitor in place of some batteries like mazda is doing to run their electronics on their skyactive models.

"compasitor"? I'm not trying to be a wise@ss here. Is this some new hybrid technology I haven't heard of yet or did you mean "capacitor"?

[rusty959]

Originally Posted by Grantmac

Are you going to run a 12v parallel to 24v series set-up like I posted? I'm seriously in favor of that option personally. Although I believe a small 12v battery might be required to run the car electronics while the system is in 24v mode.

-Grant

Thats the plan. I don't remember where you posted but my current plan is still what I posted in post #288. I was going to try to go to a 24v setup but think I am going to have to stick with 36v. Ill be posting more about that within a couple days hopefully. But yes, a 12v source will always need to be connected. I'm pretty sure the alternator cuts power at high engine loads, and you need solid voltage to power electronics as you said.
My plan (as shown on the diagram I posted) is to continue using one of the batteries in my 36v setup. However I will be using much larger batteries than most will, so I'll still have solid voltage where others might not.

(edit: I went back and checked and yes, I'm looking at the basic idea you posted about. The plan is to to run a little bit of part throttle boost off 12v and at some setpoint switch the system to 36v. I'm just hoping my motor controller can deal with the jump without frying)

Originally Posted by SkitterSkotter

This thread is so badass!! Nice work good sir! I'm excited to see the developments with this. The only issue I see thus far, and I know it has been addressed quite a bit so far, is if this can produce a decent amount of pressure. If you could get 4-8psi you are looking at a perfect set up. As far as instant power, it would be cool to throw a small motor to run off one of the wheels to charge a system...kind of KERNS style. Or maybe use a compasitor in place of some batteries like mazda is doing to run their electronics on their skyactive models.

I'm planning my setup for 10psi at redline. Ill be posting some more about this soon, been having the gf do some cad drawings for me. Not 100% it will work in practice, especially reliably/without a ton of maintenance, but it only money. lol.

A charging system off a wheel is probably too much added complexity. You not only have to deal with setting it up/controlling, but if you are using it to charge any time but under braking you might as well just draw power off the alternator since it would probably be more efficient. Yes it would be cool, but its more of an oem thing than hobby like we are doing. Don't let me discourage you if you want to try it though.

Capacitor banks are definitely a viable option. Ultra capacitors are getting pretty nifty. Neutron was planning on using some at one time and even bought some but isn't using them for now. I have considered it, and still may, but its more added cost. I'm already looking at $1k+ for just the motor/controller setup I want. Maybe I should try to get neutron to sell me his and add to it, lol.

[mid_life_crisis]

I know next to nothing about RC stuff.
What happens with one of these motors if you connect it directly to a battery? Would it burn up or just spin?
Is the controller creating a pulse or something similar that is needed or does it just vary voltage levels?
If you connected it directly to 12 volts would it spin at about 15,000 rpm, direct to 24 at about 30,000 and direct to 36 at about 45,000? Numbers just to get the idea, obviously would vary by motor.

Edit: Google is my friend. @rusty959 Apparently you don't need the controller if you are going to use relays. You could step the voltage up as the engine rpm increases, thereby increasing the motor rpm at each stage. With your design the controller itself appears to be superfluous.

[rusty959]

Originally Posted by mid_life_crisis

I know next to nothing about RC stuff.
What happens with one of these motors if you connect it directly to a battery? Would it burn up or just spin?
Is the controller creating a pulse or something similar that is needed or does it just vary voltage levels?
If you connected it directly to 12 volts would it spin at about 15,000 rpm, direct to 24 at about 30,000 and direct to 36 at about 45,000? Numbers just to get the idea, obviously would vary by motor.

Brushless motors use something similar to a 3 phase AC supply. It uses 3 wires, not 2, and none are just a ground or just a positive. If you tried to connect it in pretty much any way to a battery it would just lock in a position and then burn up. (I'm just assuming here from my understanding of them, ive never actually tried it)
The controllers are special because they have to actually be controlling the pulses that go to the motor and be flipping them around to get the motor to actually turn.

I looked up some vids on youtube, and this one looks to explain/show it. I didn't actually watch it, just kinda flipped through, so if it doesn't, blame youtube not me. :happy0180:
[ame="http://www.youtube.com/watch?v=ZAY5JInyHXY"]Brushless DC Motors & Control - How it Works (Part 1 of 2) - YouTube[/ame]

[mid_life_crisis]

@rusty959 Apparently Google really is my friend. Brushless motors are a different sort of animal. You would need a controller for that. Too bad. I thought I had dramatically simplified things. Oh well, stop learning, start dying.

[rusty959]

Originally Posted by mid_life_crisis

@rusty959 Apparently Google really is my friend. Brushless motors are a different sort of animal. You would need a controller for that. Too bad. I thought I had dramatically simplified things. Oh well, stop learning, start dying.

Yes they are a different animal, but their power and efficiency makes them worth it.

It is important to note that I will be having two types of controller in my setup that I hope people aren't getting confused. One is the motor controller which everyone doing anything with the brushless motors will need in one form or another. It will take in a signal, usually a servo signal, and drive the motor. The other is whatever decides how hard the motor should be driven. For me I am creating a custom controller using either an arduino or beaglebone. Neutron is using unichip.

[mid_life_crisis]

BeagleBone? I had to Google that. Wow am I behind the times. That is seriously cool technology.

[neutron256]

Originally Posted by rusty959

I'm planning my setup for 10psi at redline. Ill be posting some more about this soon, been having the gf do some cad drawings for me. Not 100% it will work in practice, especially reliably/without a ton of maintenance, but it only money. lol.

A charging system off a wheel is probably too much added complexity. You not only have to deal with setting it up/controlling, but if you are using it to charge any time but under braking you might as well just draw power off the alternator since it would probably be more efficient. Yes it would be cool, but its more of an oem thing than hobby like we are doing. Don't let me discourage you if you want to try it though.

Capacitor banks are definitely a viable option. Ultra capacitors are getting pretty nifty. Neutron was planning on using some at one time and even bought some but isn't using them for now. I have considered it, and still may, but its more added cost. I'm already looking at $1k+ for just the motor/controller setup I want. Maybe I should try to get neutron to sell me his and add to it, lol.

Wow 10psi at redline?! That is ambitious but it will be interesting to see how close you can get to that. I'm hoping for maybe 1psi at redline, and higher at lower RPMs.

I still might use the ultracapacitors since they are much more practical at 12V. A bank of six 3000F caps charged to 14V and then discharged at 120amps will only last about 8 seconds before they reach 12V.



Right now I'm looking at diode or switching style battery isolators for better charging of different sized batteries. This would be in addition to a relay to isolate the secondary battery in full boost situations.

[ame="http://www.youtube.com/watch?v=CGD8HAeg5UA"]Battery Isolators - Types & How to Install | Car Audio 101 - YouTube[/ame]

[rusty959]

Originally Posted by neutron256

Wow 10psi at redline?! That is ambitious but it will be interesting to see how close you can get to that. I'm hoping for maybe 1psi at redline, and higher at lower RPMs.

Being ambitious and setting high goals is what drives me.:happy0180:
Aim for the moon, even if you miss you will still be with the stars.
Or something like that.

[neutron256]

Originally Posted by rusty959

Being ambitious and setting high goals is what drives me.:happy0180:
Aim for the moon, even if you miss you will still be with the stars.
Or something like that.

I take the a different approach. Before I even think about going to the moon I need to make sure I can at least get into earth orbit.

[fenton]

Originally Posted by rusty959

Being ambitious and setting high goals is what drives me.:happy0180:
Aim for the moon, even if you miss you will still be with the stars.
Or something like that.

Very ambitious ... 10 psi at redline will take 21kw

Sent from my HTC One using Tapatalk 4

[neutron256]

I think I've found the battery isolator I'm going to use.
http://www.sunforceproducts.com/prod...PRODUCT_ID=153



Install is very simple, just on wire from the positive lead of your main battery and a second to the positive lead of your secondary battery. It also has a small ground connection for powering the unit itself.

What I really like about this is that it will also isolate the secondary battery whenever the units small ground connection is removed. This will allow me to use a much smaller relay.

Thoughts?

[rusty959]

Originally Posted by fenton

Very ambitious ... 10 psi at redline will take 21kw

Sent from my HTC One using Tapatalk 4

Awesome, thats right around what I calculated.