Small Stirling Engine

[Grasnal]

Hi, folks. I am new here and I would like to have your suggestion for a trouble that I have. A few time ago I have bought (for learning purposes) from China, a small Stirling Engine that when working activates (via a rubber band) a small DC motor in order to generate DC voltage to light up a small LED. On advertisement i was stated that this motor would be able to generate 4Volts DC, more than enough for any small LED. Right on first test, I have wondered that the LED (once correctly polarized) was not working. Then I have decided to measure the "output" of the DC motor and there was only 0.180mA, what is too low. I have verified that rubber band is conveniently streched and DC motor runs freely. Any suggestions regarding to any additional test ? I thank you guys in advance. I was trying to use this device in my classes, showing the feasibility on converting heat in electrical current, what was obviously damaged.

[thanh-cuibap]

Can you show the image engine ?

[Ian S C]

To put a photo up click on the box to the left of the Submit box, click on insert image, then attachments. You may need to reduce the photo size, I use 640 x 480, and just bring it straight from your computer. The only motor I'v bought is this one, I build my own.
Ian S C

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[Grasnal]

Thank you for your quick reply and interest. I will try to attach the picture of my device. Please let me know if it is not properly visible.

[thanh-cuibap]

Hi Grasnal !
You should try with a 1.5 volt LED
If not light, you should do the circuit for it, very simple and easy to do.
http://electronics-diy.com/led-flashlight-1.5v.php

[Ian S C]

The little Bohm HB7-A02 often needs the power cylinder, and piston cleaned, I use a bit of paper kitchen towel, it has a stainless piston in an aluminium bore, not a mix that I would use.
My own small motor has a 3/8" bore by 1/2" stroke, both the piston and cylinder are cast iron. The flywheel is 50 mm dia.
Ian S C

[Grasnal]

I thank you so much for this suggestion. I will certainly try it, although the Voltage generated at motor-generator is only 0.18Volts and this circuit, as far as I have understood, need at least 0.3 Volts. Has anyone not have the same trouble as me, when buying such engine ?

[thanh-cuibap]

Hi Grasnal !
I think it will be okay with 0.18Volts .
I used it for my engine
https://www.youtube.com/watch?v=e850NKFEFW4

[Grasnal]

Thnak you. I can't wait to assemble the Joule thief circuit and see the results. On your video (on Youtube), I noticed that you are using a support for the led quite similar to the one I have intended to use. I tried to find cheap railroad modeling lamp supports but they are only sold on great quantity and this let them expensive.

[thanh-cuibap]

It's quite simple if you have a lathe, otherwise you can ask someone have the lathe do it.

[cbstirling2]

I have the same Stirling engine and "generator" and I believe it easily lights the led. Perhaps the generator is faulty presuming your engine has good RPM.

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