power for using an alternator for battery charging?

[ron17571]

Hawke that looks like the one I was checking out, it had two tubes sticking out the top.

[Hawke]

Yes, mine has two as well, both were broken off at the base. I drilled out and made the fitting for the pressure in. I cant remember but the second tube might be for exhaust. You can buy kits at www.ministeam.com for several types.

The PM2A Kit
http://www.ministeam.com/acatalog/PM_Re ... ts-p1.html

[Hawke]

Here's another I purchased. Runs good on compressed air. Heavy lil dude with good precision components. I'd be open to selling this one I guess.

[Ian S C]

Might be best if we get back to STIRLING and Hot Air engines. Ian S C

[Hawke]

Hahah, theres a dedicated Stirling man! Well ...it does fit the theme of the thread Sir Ian.

[Ian S C]

Don't worry Hawke, it's a good idea to divert occasionally, to compare other forms of engines, and even PV cells. Ian S C

[fullofhotair]

http://youtu.be/TRLVhKzamUE
What if you used a bedini motor generator to charge your batteries. He is using it as a motor here ,but if you powered it with a stirling engine,and used it as a generator. He said it works better at lower power. That would also be lower rpms I assume.

[Ian S C]

fullofhotair, have you built one of these Bedini motors? Sorry if I sound sceptical, I'd say its B**l S**t, but have a go any way, just remember that you must put in more than you get out with any method of generating electricity. Ian S C

[theropod2]

Voltage Pulse Schematic

voltage_pulse.jpg (90.58 KiB) Viewed 7366 times

Here is the schematic I referenced earlier. It's a really simple build, and the 2 555 timers could be replaced with a single 556 or even one 555, but the single timer won't allow a variable pulse width. With the two timers the first timer sets the delay between pulses and the second sets the length of that pulse. Care should be taken to avoid overlap, where the pulse duration exceeds the delay or the circuit will stay in the constant ON condition. All parts voltage values are set for a 12V system and if higher voltages are involved these parts should be rated for that voltage.

The zenner diode (lower right corner) should have a breakdown voltage 5 or 6 volts higher than the battery bank voltage. This way if the capacitor bank voltage goes high between pulses the mosFET will fire before the timers can cycle.

R

[fullofhotair]

theropod2,
Is this what you would use with a small(12 in. stator), three phase axil flux alternator?

Ian SC, I have just made a simple bedini motor long ago. I had no testing equipment ,so had no idea if it was efficient. You can get caught up with the claims on U-tube. I never fell for the overunity thing, but thought it might be an efficient generator at low rpms. Any stirling engine I build is going to be on the weak and slow side .So I need everything I can get out of her. The axil flux alternator looks like it would be a lot better than using an electric motor for an alternator. I think building it and the circuitry is going to take longer than building the stirling engine, but that is all the fun. Especially if it works.

[Hawke]

Though maybe not quite matching the theme of this thread and/or slightly off topic, Id like to comment on Full's post.....

... a lot better than using an electric motor for an alternator.

I am on board with that too Full. Ive been thinking of running a lamina flow engine from the heat coming off the vent from heat chamber on my model gamma. The lamina might run the peltier module under my planned cooling tank thus not putting a load on the gamma.
I like the design of this one, especially the adjustable spacing.
http://www.youtube.com/watch?v=cAyw_dOi ... D4A6C98458
I think coil/coils around the cold side and a magnet attached to the piston might produce more voltage however. A coil could be moved to tune things as well.
See 3:00 in on this one:
http://www.youtube.com/watch?v=Jo9BssYy-sY
ANother design:
http://www.youtube.com/watch?v=EoJY5h_8NLY
************
I tell ya Im still doing just models and finding the stirling engine is quite a fun little hobby. I looked at a lathe at Harbor Freight this weekend. ....Someday

[Ian S C]

Hawke, go for it, don't wait too long for the lathe, get as big as you can afford/got room for, from what I hear HF have some good gear.
full, I,m using an old hub dyno from a bike on my Ross Yoke engine at the moment, it's designed for low revs, some where around 120 rpm is quite good, and I feed it through a bridge rectifier, and a large smoothing capacitor. I origionally intended to use the hub dyno on a wind turbine. Ian S C

[fullofhotair]

Hawke,
I really like that first video you posted. It is really compact and does what I want , produce light with medium flame. My plan is to use one of those penny can alcohol stoves. Iam going to use a lamp mantle over the flame to produce even more light. You have to use special mantles I ordered. The coleman mantles wont work. I think the catalyst action even produces more heat with the same amount of fuel. Iam just wondering if I can use a graphite piston?

Ian SC,
Do you have any pics of your engine using the bike dynamo? Iam just trying to picture how the dynamo is attached to the engine. The dynamo isn't attached directly to the flywheel axil is it?

[theropod2]

theropod2,
Is this what you would use with a small(12 in. stator), three phase axil flux alternator?

No. I'd make the stator match the expected voltage of the load (battery) plus a little for rectifier losses in a axial flux alternator, say 15 volts DC for a 12V system.

I'd use the little pulse charger when the source "likes" to produce a higher than load voltage but with little amperage. This can use the cap bank as a pre-battery that can go WAY over the load battery voltage and then send a series of pulses of significant amperage as the caps discharge so fast. The battery will "clamp" the over voltage spikes. As I said I wouldn't use this in association with sensitive loads as those spikes can play havoc with some voltage sensors.

Ian SC, I have just made a simple bedini motor long ago. I had no testing equipment ,so had no idea if it was efficient. You can get caught up with the claims on U-tube. I never fell for the overunity thing, but thought it might be an efficient generator at low rpms. Any stirling engine I build is going to be on the weak and slow side .So I need everything I can get out of her. The axil flux alternator looks like it would be a lot better than using an electric motor for an alternator. I think building it and the circuitry is going to take longer than building the stirling engine, but that is all the fun. Especially if it works.

You might not need to reinvent the wheel with the alt. Look for old VCR's or 3.5" disc drives. Those sometimes have a thin little stator and one side of the dual discs. Making new discs for your flywheels would work too with old hard drive magnets glued on. Those neat little coils can be loosened and repositioned as needed if proper care is taken. Worse comes to worse you can build a little jig to wind those coils. No more than you would be pushing this the coils could be superglued on a CD, or other thin and non metallic base.

Just Google the design and also for those old motors. I'd use rare earth magnets, doing away with the ceramic discs they come with is the best upgrade possible.

Brushless pancake motor (really good link, scoll down for this pancake motor for what I'm talking about). Bypassing all the motor crap and this is then an alt when spun.

R

[fullofhotair]

Thanks theropod2,
The old VCR, seems like the way to go.