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Author Topic: Hobby Boards Solar Sensor  (Read 4487 times)

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Offline Nikki

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Hobby Boards Solar Sensor
« on: April 08, 2008, 10:23:02 AM »
Hello everybody

I have a quick question regarding the correct alignment of a HB solar sensor.

Currently I have my sensor pointing towards the midday sun but unfortunately this misses the sunrise (6:20am) right through to about 10:30. Today for example we had a very sunny morning but my solar sensor was only showing 30% and hence reporting a cloudy day. At 10:15 my solar percent started to increase and at 10:50 it was showing 100%.

If i move the sensor more towards the East then i can catch the morning sun but miss the late afternoon sun.  :roll:

Would it be better to mount the sensor with the diode pointing directly at the zenith instead? Would this still work efficiently?

I have also considered mounting a small mirror on the North Western side of the sensor aligned in such a way to reflect the sun back onto the sensor.

Any thoughts?

Thanks
Nikki


Offline Budgie

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Re: Hobby Boards Solar Sensor
« Reply #1 on: April 08, 2008, 10:29:33 AM »
I think the instructions say to point the diode straight up towards the sky, that way you get the best readings from the 140 view of the diode.  :wink:

It'll be interesting to see what happens with mine at the height of summer because up here the sun rises in the NNE and sets in the NNW. So I can't really point it in any particular direction.  :D
« Last Edit: April 08, 2008, 10:31:50 AM by Budgie »

Offline TokKiwi

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Re: Hobby Boards Solar Sensor
« Reply #2 on: April 08, 2008, 10:35:15 AM »
It really needs to be totally horizontal and pointing vertically as best as you can.  But it is believed to be an advantage if you have a translucent bulb or shield over it to get a better early morning and late afternoon response and then get it set correctly at zenith which may be sometime close to 1pm for you - can be plus and minus a bit away from the longest day, esp either side of equinox.  Still, it is not an accurate device as the respoinse from the 1-Wire led's is not perfectly linear. But it gives you a close approximation.  Some have used a large electric light bulb or an external globe, removed the internals and mounted the sensor inside.  There are some threads sharing different optiions.

cheers

Graeme
Dad's have hobbies because they are children's rugby, football and Committee Fathers!!

Offline Nikki

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Re: Hobby Boards Solar Sensor
« Reply #3 on: April 08, 2008, 11:13:56 AM »
Hi Guys

Thanks for such a quick response.

I have mirrored Henriks setup by using a small defusing cap (please see henrik's photo at)

www.buskelundtoften.dk/vejret/english/udstyr.php

(Sorry don't have a picture of my own setup as I'm at work at the moment, however my setup is almost exactly what henrik has done with his)

I'll change the alignment this evening and point it towards the zenith, see what happens...

Once again thanks for your help

Regards
Nicola


Offline Breitling

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Re: Hobby Boards Solar Sensor
« Reply #4 on: April 08, 2008, 11:47:41 AM »
You will always have some "blind angles" with the Hobby Boards solar sensor. It has a 140 aperture. In addition you could have some shadows from near objects. If you can't install the sensor in an open area, the only way to get rid of that shadows is rising the sensor location.

Offline jwwd

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Re: Hobby Boards Solar Sensor
« Reply #5 on: April 08, 2008, 11:52:32 AM »
Hi Guys

Thanks for such a quick response.

I have mirrored Henriks setup by using a small defusing cap (please see henrik's photo at)

www.buskelundtoften.dk/vejret/english/udstyr.php

(Sorry don't have a picture of my own setup as I'm at work at the moment, however my setup is almost exactly what henrik has done with his)

I'll change the alignment this evening and point it towards the zenith, see what happens...

Once again thanks for your help

Regards
Nicola



Hi Nicola

Im glad I could help you - I hope you get your solar sensor working fine.

Best regards,

Henrik

Offline Nikki

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Re: Hobby Boards Solar Sensor
« Reply #6 on: April 08, 2008, 11:58:31 AM »
Hi Nicola

Im glad I could help you - I hope you get your solar sensor working fine.

Best regards,

Henrik

Really appreciate the help  :D  :D :D :D :D


Offline Nikki

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Re: Hobby Boards Solar Sensor
« Reply #7 on: April 08, 2008, 12:06:54 PM »
You will always have some "blind angles" with the Hobby Boards solar sensor. It has a 140 aperture. In addition you could have some shadows from near objects. If you can't install the sensor in an open area, the only way to get rid of that shadows is rising the sensor location.

I know, its a bit of a shame  :(

I have had one thought, what if i mounted the sensor facing a small wide-angle parabolic reflector at the exact focal point, would this improve things at all?



Nikki


« Last Edit: April 08, 2008, 12:14:00 PM by Nikki »

Offline Breitling

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Re: Hobby Boards Solar Sensor
« Reply #8 on: April 08, 2008, 12:27:59 PM »
I have had one thought, what if i mounted the sensor facing a small wide-angle parabolic reflector at the exact focal point, would this improve things at all?

You will never had a 180 view angle with a parabolic reflector. And on the other side, you'll be measuring reflected radiation. The goal is to measure global radiation: direct + diffuse + reflected.

HB solar sensor has some limitations, apart of a not demonstrated linearity in its response. I think the best way to install it is the Henrik's setup.
« Last Edit: April 08, 2008, 12:31:15 PM by Breitling »

Offline Nikki

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Re: Hobby Boards Solar Sensor
« Reply #9 on: April 08, 2008, 12:34:15 PM »
You will never had a 180 view angle with a parabolic reflector. And on the other side, you'll be measuring reflected radiation. The goal is to measure global radiation: direct + diffuse + reflected.

Hi Breitling

Thanks for the reply - i suppose so, just a silly idea really  :oops:

TA
Nikki



 

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