Hi everyone,
I've recently introduced myself to the world of personal weather stations, and I would like here to share what I did, it may be useful for other "hands on" weather enthusiast.
I've choosen to start buying a cheap weather station, a WH3080 SE with solar and UV sensors (the chinese one that you can find virtually everywhere under Aercus/FineOffset/Excelvan/WeatherWise/PCE/froggit/whatever brand )
Put it toghether on the balcony just to test, I discovered that it's own shield is really crap #-o (to be honest another weather station owner already warned me)
So this is why I got from ebay a used Davis Instruments 24h Fan Aspirated Shield to play with:
Apart from the fact that the item needed some work to get it work properly, I found out that the FARS does not have a large chamber like the passive one, it has a sort of cylindric space in the center, and the sensor needs to be fitted in there:
The temp/hum sensor (which is also the radio transmitter to the console ) is much much larger, It couldn't possibly fit in there, so I opened it up:
Two good news here:
1-the pcb inside is much more little and can fit in the Davis shield chamber
2-Unlike other versions of the same chinese station that I found on the internet, this has a real antenna, not just a couple of inches of track on the pcb. This improvement I immagine is part of the "SE" (2016's second edition) version of the station. I must say that radio transmission is good, it never looses a bit and the console is quite far from the transmitter. Good.
At this point I had to think about how to put it in there, how to protect the nude pcb from humidity and how to put there the batteries too.
1-I cut a square of prototyping board the exact size of the real davis sensor pcb, to make use of the original slot inside the shield sensor
2-I covered the pcb of the sensor/transimitter with bicomponent silicone gel, a specific product to protect circuits and wirings from moisture and so on. I used this product from etelec http://www.etelec.cloud/en/products/low ... pgel-plus/ just because it was easy for me to get that from the local store, there are many brands out thewre and I think they are all the same
However I don't know if I would reccommend this solution, I found out that the gel, even when reticulated, is really...jelly #-o
It was difficult to manage, if I had to do it again I would try harder and find some kind of conformal coating
3-I soldered the batteries in series and protected them into thermo-shrinkable tube
4-Put this all components toghether like this and soldered battery wires to the transmitter pcb:
5-Put the packet in the slot into the Davis 24h fan shield (I had also to destroy the unuseful original shield to free the cable coming from the UV/solar panel):
6-Reassembled everything like this and put it on top of a pole which is a few feet higher than the top of the roof
The results in my opinion are very good, i have an airport within 10 miles and the temperatures reported by my station are quite the same of the METAR data from there.
If anyone is interested my ID on wunderground is ICASSINA21
https://www.wunderground.com/personal-w ... ICASSINA21
I got the "gold star" from wunderground almost immediately (about 12 hours after starting data upload), which is enthusiastic but...shouldn't it be a 5-day evaluation??
I hope anyone can find my DIY homework interesting or useful
Bye
Luca (from Italy www.meteocassina.it )
How I adapted Davis 24h fan shield to a WH3080 station
- Johnny
- Developer
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- Location: Watford, Hertfordshire, England
- Station model: Davis Vantage Pro2 Plus
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Re: How I adapted Davis 24h fan shield to a WH3080 station
Hi Luca, I have the exact same weather station as you, mine is branded Aercus. You have clearly experienced the same thing as the rest of us with these inexpensive weather stations, as soon as the sun shines on them the temperature starts to creep up and gives readings which are clearly wrong.
So I set to task as you have done - to use a fan to keep the air movement across the sensor steady and it works. However my approach was different to yours, I strapped a 12v PC fan to the existing shield. To keep it going I used a 10 watt solar panel, a cheap solar controller and a small 12v Yuasa battery.
In the summer this works fine, in fact you can leave the fan on 247, but I now notice with the light falling each day that I have to set a reminder to turn the fan on in the morning and off in the evening (as the battery starts to get quite low). This would indicate that a higher wattage solar panel would be in order.
Anyway it all works and the temperature from both this and my Bloomsky are usually very close and not to dissimilar to those from Heathrow Airport
So I set to task as you have done - to use a fan to keep the air movement across the sensor steady and it works. However my approach was different to yours, I strapped a 12v PC fan to the existing shield. To keep it going I used a 10 watt solar panel, a cheap solar controller and a small 12v Yuasa battery.
In the summer this works fine, in fact you can leave the fan on 247, but I now notice with the light falling each day that I have to set a reminder to turn the fan on in the morning and off in the evening (as the battery starts to get quite low). This would indicate that a higher wattage solar panel would be in order.
Anyway it all works and the temperature from both this and my Bloomsky are usually very close and not to dissimilar to those from Heathrow Airport
- nikokara - BANNED
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- Station model: ng265 (Fine Offset)
- Software: Cumulus
Re: How I adapted Davis 24h fan shield to a WH3080 station
Hi Johny
I have bypass the battery and power direct a laptop fan (5V 0.02A no 12V as PC fan) with two cheap solar panel from a garden solar led light(1 euro each) but in serial syndesmology (1,2+1,2V = 2,4V). The fan turns on at a voltage 1,8V. When the sun is shining it gives ~2,5V when not below 1,8V, and the fan stops turning, Same in the night. The temperature readings are compared to a professional station +- 0,2 grad.
And sorry for my "very good" English
PS. May be in parallel syndesmology the solar panels give more mA with 1,2 Volt current, but i have not tested
I have bypass the battery and power direct a laptop fan (5V 0.02A no 12V as PC fan) with two cheap solar panel from a garden solar led light(1 euro each) but in serial syndesmology (1,2+1,2V = 2,4V). The fan turns on at a voltage 1,8V. When the sun is shining it gives ~2,5V when not below 1,8V, and the fan stops turning, Same in the night. The temperature readings are compared to a professional station +- 0,2 grad.
And sorry for my "very good" English
PS. May be in parallel syndesmology the solar panels give more mA with 1,2 Volt current, but i have not tested
niko
- Johnny
- Developer
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- Location: Watford, Hertfordshire, England
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Re: How I adapted Davis 24h fan shield to a WH3080 station
Hi nikokara, not such a bad idea to bypass the solar controller and battery and go from solar panel straight to the fan. I'll try this out with a lower wattage solar panel as they can kick out 22 volts in full sunshine, a 12 volt fan may not like that continuously - my weather station may take off.
- nikokara - BANNED
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Re: How I adapted Davis 24h fan shield to a WH3080 station
Johny hi
You can also leaf the battery and the controler and add a LDR = Light Dependent Resistor, between battery and fan, but you net a transistor or a relais to, This means you need a additional circuit board
Typical LDR resistaces are
Light = 5kΩ
Dark = 20MΩ
Its easy and low cost
Then you have not to set a reminder to turn the fan on in the morning and off in the evening
You can also leaf the battery and the controler and add a LDR = Light Dependent Resistor, between battery and fan, but you net a transistor or a relais to, This means you need a additional circuit board
Typical LDR resistaces are
Light = 5kΩ
Dark = 20MΩ
Its easy and low cost
Then you have not to set a reminder to turn the fan on in the morning and off in the evening
niko