Sandaysoft

Hi Ole
I came across www.technicalglass.co.uk who might help. They mention making products "to keep a production line going" which sounds to me as though they are prepared to make small quantities of components as replacements for things that get broken. I guess small quantities of pcb's are again uneconomic for most makers but www.p-m-services.co.uk sounded like a small enough company who might be interested.
The UV monitor sounds a good idea with people getting more concerned about skin cancer (here in Cornwall the air is very unpolluted and visitors here often underestimate the effect of the sun - a lot of very red people on the beaches). I would guess you'd only need a small window of quartz glass (maybe a tube) as the detector would need to see around 270 degrees of sky. I'm not familiar with UV detectors - can they be omnidirectional ?
Regards
Alan

Wow, I often drive past that PCB place - what a small world.

_________________
Nothing is foolproof, to a sufficiently talented fool . . .

WH1080PC Rochdale UK, 171m

Hi Keith
That could be handy - maybe Ole could let you have the details and you might be kind enough to call in and see what they could do - nothing like the personal touch.
Regards
Alan

Hi Alan,
Actually in the meantime I came across Acrylic cylinders which comes in many different diameters.
I also found out the acrylic should be very weather and UV ignorant so I think I will go for that in the next design.
I have also investigated a little bit more on UV sensors - there is a few available but the cost is relative high (around £ 30) and not to complicate the project I think we should leave that out until Sun Recorder MK2 pops up on the design desk.
PCB's: it is always a problem for us home-makers but is is almost impossible to handle the smalls chips.
I do have some friends in Chicago whom I have used as post forwarder before - the shipping from Express PCB within US is only $6 instead of $55 to Denmark. The problem with PCB's is always the initial set-up cost while the PCB itselt is not a costly issue (meaning ordering 3 or 10 does make a very big difference).
I might consider to make up a breadboard test of the 1-wire system before jumping into a PCB.
And: FINALLY SOME SUN SHINE
The attached graph shows the result.
My software used GMT + 2 hours (still on summertime) so the dawn was at 07:55 and sunrise was 08:34 on the scale - unfortunately I was not observing the sunrise itselft, but there was some fine clouds in that direction when I went up.
It seems that sun is reflected between 08:09 and 08:29 - that timing is not fully in line with the sunrise time - I think it might be caused by a higher refraction than normal.
Between 08:29 and 08:40 you see a drop - quite sure that a cloud was there.
My next plan is to have my digital camera remote controlled by the software taking a picture say every 1 min so I can establish a correlation to the data and the real life.
But up to now I think the data looks OK for our purpose.
Best regards

Ole

Hi Keith.
I checked some sample quotes on http://www.p-m-services.co.uk/ - prices looks very attractive compared to my US alternative and also compared to my professional experience here in Denmark.
I have attached a 1:1 size pdf drawing of the how the PCB is going to look although it is NOT the final design.
It would be great if you could just pop in and ask for a budgetary price.
Please also ask if they accept files in Protel format.
Best regards
Ole

Hi Ole
I'm not sure of the definition of sunrise - it may be when the whole of the sun disc is visible in which case your pre sunrise reflection could be the partial disc. I've found a compnay here in Cornwall that makes things like tumblers out of recycled bottles - they might be able to cut a tube from a suitable bottle. I could talk to them on Monday. I think the diameter was 83mm (I'll look back in the posts) but something close would probably be suitable.
Regards
Alan

Hi Alan,
I appreciate your idea but I will go for the acrylic solution because you can drill holes into it for fixing of the internal stuff.
Please refer to attached which shows how I plan to implement the next prototype.
I have found a vendor here for the acrylic tube - ø 70/64 - length 2 meters at approx £40 - 2 meters is enough for approx 20 recorders should need be.
Best regards
Ole

Hi Alan,
Sunrise: as far as I have been able to queeze the internet it is defined as when the apparent top of the sun just is at the horizon.
If that's a fact it does not fully fit into the recorded data - I will investigate further.
Best regards
Ole

If I remember correctly

The US (and most of the world) define rise as the tip of the disc can be seen and set as the moment the disc disappears.

UK definition is 50% of disc visible, this is realistically only going to make any great difference toward the poles, where there will be times where it never fully rises / sets, at the tropics, although the disc is much larger, it rises and and sets MUCH more rapidily, so not a problem.

Great work guys !

Thought - if you already have TTL at the sensor, what about working (USB) RS485 instead of RS232 ?

_________________

......................Imagine, what you will KNOW tomorrow !

Thank's the input about sunrise definitions. UK - left drive and different sunrise
In my present sundetector it's pure analog down to the USB A/D Converter and because of the relative low signal levels I have experienced some noise problems - both leads are decoupled by 22uF but that again creates some current leakage.
In the next one I intend to use a 1-wire system.
The 1-wire is also a serial protocol - relatively low speed which do not matter for this application.
Funny name by the way - it will never work without a ground wire - even here in DK we can count to 2.
In the actual case it will be +5V, signal and ground = a 3-wire system.
Best regards
Ole

Hi Ole
I was just looking back at your pre sunrise anomaly and I wondered if it could be aircraft landing lights - the rising level suggests something getting closer and the peaks and troughs might be small movements of the aircraft sometimes shining directly at you. Are you near an airport ? I don't think it could be road traffic - you'd expect it to occur earlier as well. The real sunrise showed up very well - that's the area my primitve design failed on and it does need manual level tweaking every couple of weeks.
Where I am I'm always going to lose some early and late time as I have hills rising a few metres above my altitude in the NE to SE and SW to NW quadrants - I can see the sea horizon to the south but that is not exactly useful.
The latest design drawing looks really good - having the PCB inside might provide just a little heat to counteract condensation. Maybe if you had a higher supply voltage and used the heat from a voltage regulator (it wouldn't be much but in an enclosed vessel it might help) and it might provide a more stable circuit voltage as well.
Once again I have to thank you for your enthusiasm and skill - I believed in the idea but my knowledge wasn't enough to take it where it should go.
Regards
Alan

Hi Alan.
It is probably right that I have the best experience in electronics and programming, but your imagination and ability to 'turn every stone' is remarkable - the way you think and try to find solutions is in my opinion outstanding.
To illustrate I am impressed of the fact that you stubled over the MCloed concept from 1800 something and replaced the original light sentive paper with a photoresistor to see if that could be a method to count sunshine hours.
And I am 100 % sure we are on the right track - why nobody else have got the same idea is strange.
It's a little bit like the Lego system - so simple that anybody could do it - but only one did.
No - we don't have an airport close and also road traffic is somewhat distant - my house is in the real country side.
So what caused the initial light pop up is more likely to have been some remote clouds being hit by the sun light even before i was above the horizon.
I think my idea to set up my camera will provide the documentation required to compare the actual optical conditions with the measured results.
The AD converter I purchased have a spare digital output so I can operate the camera by my software as I choose. Fortunately my place is in fairly high altitude (danish standard at least) of 79 meters above sealevel and I do have about 3-4 km free view in the present sunrise direction from my first floor.

I just briefly checked the USB specs and it seems that a load of 500mA should be possible.
The 1-wire circuit has a very low power consumption so i might consider to include a 15 ohm resistor in - it will give a nice continious heat of 1.6 watt.
Best regards
Ole

Hi Alan.
I got my camera in operation now.
When sun is at elevation -6 to 6 (only AM) it takes a picture every 1 min.
Attached is an example - camera looking at SE.
It looks through some oak trees - the leaves will drop off with the next week or two providing a better look through the branches.
So now - waiting for some sunshine (the recorder works perfectly at present - sunshine hours = 0 )
I will order some 1-wire evaluation stuff today and then see how difficult it will be to get it operating.
Best regards

Ole

Hi Ole
I was assuming you were using an external power supply when I suggested the voltage regulator - I think usb cables are limited to 15M but I don't know if that is a data or power limitation.
I saw the sun for an hour or so today after the low cloud lifted so maybe it's heading your way.
Regards
Alan

Hi Alan.
It's correct that USB cable lenght is limited due to data speed, but as I will use 1-wire system, the cable length is not a problem except for voltage drop if I am loading it to much for the heating.
I intend to use my laptop as permanent computer for the recorder and maybe the 5V output capability is less that the 500 mA.
So the internal heating is an open issue so far but I think that some small ventilation holes plus maybe 200-300 mW will be able able to handle a mist problem.
I will anyway design the PCB so a resistor can be mounted for that purpose.
Yes please - ask the clearing to move toward my place - my camera will be ready tomorrow morning.
Best regards
Ole