Small Stirling Engine

Discussion on Stirling or "hot air" engines (all types)
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Grasnal
Posts: 4
Joined: Sat Aug 04, 2018 10:17 am

Small Stirling Engine

Post by Grasnal » Sat Aug 04, 2018 10:30 am

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
Posts: 162
Joined: Tue Sep 06, 2016 8:09 am
Location: Việt Nam

Re: Small Stirling Engine

Post by thanh-cuibap » Sun Aug 05, 2018 10:03 pm

Can you show the image engine ?

Ian S C
Posts: 2154
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Small Stirling Engine

Post by Ian S C » Mon Aug 06, 2018 4:06 am

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
Posts: 4
Joined: Sat Aug 04, 2018 10:17 am

Re: Small Stirling Engine

Post by Grasnal » Tue Aug 07, 2018 8:50 am

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.
Attachments
Picture of my item.jpg
Picture of my item.jpg (30.51 KiB) Viewed 1205 times

thanh-cuibap
Posts: 162
Joined: Tue Sep 06, 2016 8:09 am
Location: Việt Nam

Re: Small Stirling Engine

Post by thanh-cuibap » Tue Aug 07, 2018 5:30 pm

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
Posts: 2154
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Small Stirling Engine

Post by Ian S C » Wed Aug 08, 2018 5:10 am

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


Image
Attachments
032 (640x480).jpg
032 (640x480).jpg (131.81 KiB) Viewed 1189 times

Grasnal
Posts: 4
Joined: Sat Aug 04, 2018 10:17 am

Re: Small Stirling Engine

Post by Grasnal » Wed Aug 08, 2018 9:56 am

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
Posts: 162
Joined: Tue Sep 06, 2016 8:09 am
Location: Việt Nam

Re: Small Stirling Engine

Post by thanh-cuibap » Wed Aug 08, 2018 10:29 am

Hi Grasnal !
I think it will be okay with 0.18Volts .
I used it for my engine

Grasnal
Posts: 4
Joined: Sat Aug 04, 2018 10:17 am

Re: Small Stirling Engine

Post by Grasnal » Wed Aug 08, 2018 2:30 pm

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
Posts: 162
Joined: Tue Sep 06, 2016 8:09 am
Location: Việt Nam

Re: Small Stirling Engine

Post by thanh-cuibap » Thu Aug 09, 2018 7:04 am

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

cbstirling2
Posts: 146
Joined: Sat Dec 17, 2016 9:35 pm

Re: Small Stirling Engine

Post by cbstirling2 » Sun Aug 19, 2018 7:10 am

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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CBStirling2

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