Autocostruzione schermi solari

**Gigi600** · 22/06/2009, 20:57

Originariamente Scritto da fabrym

quindi secondo te' si puo' lasciare anche senza ventilazione?

Dipende dal posto

Nella mia zona nelle giornate calde c'è sempre stato un po di ventilazione

fino ad ora

Vedrò nelle giornate calde senza ventilazione.

Gigi

**calton** · 23/06/2009, 08:03

ciao a tutti,
mi chiamo stefano e ho appena acquistato una la crosse 2308. stavo cominciando ad autocostruire lo schermo solare,ma ho trovato un piccolo problema...non riesco a trovare i piatti di melanina!!

qualcuno mi sa dare qualche dritta su dove cercarli?ho provato al centro commerciale ma niente...

ps:questo forum è bellissimo,complimenti!

**weather1967** · 29/06/2009, 17:20

Originariamente Scritto da weather1967

Hi all
I make a electronic design (and i thing to build it )for to work a pc fan in a radiation shield
The day it will turn foul turn with 12 volt dc ,at the night at half turn with 6 volt dc
For low drop the volt from 12 volt to 6 volt i use one resistor 80 ohm at 1 watt from the type :
12-6/0.075 =80 και 6*0.075 = 0,45w
Sollar panell --> charge controller-->battery-->80 ohm resistor to relay for 6 volt dc at fan the night.
Solal panel--> 12 volt at fan the day ,
Solar panel -->i use 162 ohm resistor for drive to relay to cut the contacts to relay at 10 volt dc and down because before without resistor the relay closed the contacts at 7 volt dc (i make experiments with a power suply 0-30 volt).
Fan--> to relay
When it is day with sun solar panel give 12 -16 volt and the relay closed to batery circuit and solar panel it give power to fan ,the night the when drop the power from solar panel ,open to circuit to relay and give power to fan from the battery .
Tha material it is
A sollar panel 12-16 volt 5 watts or 10 watts for better results
5W Solar Panel Kit > Maplin

A charge controler 12 volt 5 amber
Solar Charging Regulator > Maplin

one batery lead acid 12 volt 2,2 Ah,οr 7,2 Ah for better results.
???????? Lead acid 12V 2,2Ah CSB

a pc fan for radiation shield 12 volt 8 x 8 cm
??????????? 80*80mm ???????? (17dB) ?? ???????? ??????? [COOLTEK 130] - €8.00 : elektronik.gr, electronics

one relay 12 volt 2 contacts
???? ???? ???????? 12VDC 2 ?????? 2 ?????? 250V 5A [SMI-S-212D] - €2.00 : elektronik.gr, electronics

a water proof case for to put inside batery,charge controler,pcb with relay and 2 resistors
???????? ??????? ????? 240 x 190 x 90 mm, GW44208 :: ??????? ?????? :: ????????????? ????? :: ??????????? ???????

Here it is the electronic design

Today i build the pcb with components
Resistor i use one 150 Ohm + one 10 Ohm at serial for to make total resistor 160 Ohm for drive to relay and one 82 Ohm from battery to relay .

**weather1967** · 29/06/2009, 20:10

Ηi again i up load a video about test the electronic circuit , with two power supply 12 volts,and all work fine .I measurement the current mA with two multimeters.

http://www.youtube.com/watch?v=_VCyMmtCSvM

**weather1967** · 06/07/2009, 17:33

Ηi again
I make a electronic circuit with 2N2222 tranzistor, and CA3140E microcircuit, i drive to relay with better accurace,with trimmer i tuning at how voltage i want to drive the relay.
I have some photos
All it is the same with other project ,except the relay circuit
Fan turn the day with full speed ,and the night at half speed.

**Conte** · 06/07/2009, 19:23

Very professional!

**Orso Polare** · 06/07/2009, 21:43

Hi Dimitris.

Good project and ....fine drawing

Only one thing... why your choise to run fan at half speed in the night??

**weather1967** · 06/07/2009, 22:54

Originariamente Scritto da Orso Polare

Hi Dimitris.

Good project and ....fine drawing

Only one thing... why your choise to run fan at half speed in the night??

Τhank you Conte and Orso Polare

The fan and solar panel where we use it turn the fan only the day with sun light ,but if we want to have 100 % correct temperature the cold clear winter nights,must the fan inside to radiation shield to turn and the night with half speed ,like Davis weather station ,look the Davis weather station model 6153 and over ,you will see the fan turn 24 hours at day ,the day foul speed ,and the night with half speed .

http://www.davisnet.com/weather/products/weather_product.asp?pnum=06153

For the reason :
It is necessary for the cold nights with temperature inversion the cold air make reflaction from the ground to up ,if we do not have fan the sensor it can to show very lower temperature early the morning ,where it is wrong ,if the fan turn to half turn ,put up the cold air from the radiation shield and the temperature it is more normal.
I have found some photos from Davis weather design and the batteries for the fan at night at half speed .

**Conte** · 06/07/2009, 23:04

Originariamente Scritto da Orso Polare

Hi Dimitris.

Good project and ....fine drawing

Only one thing... why your choise to run fan at half speed in the night??

I suppose because in the night necessary less ventilation than day time. So it possible to consume little amount of elettric energy then a little battery or the same but for more time without solar light.

**Orso Polare** · 06/07/2009, 23:28

Originariamente Scritto da Conte

I suppose because in the night necessary less ventilation than day time. So it possible to consume little amount of elettric energy then a little battery or the same but for more time without solar light.

Yes, that's right but....in the night R4 82ohm 1W expend power....
On day the battery power only the fan.
In the night, battery power fan and resistor, the total watt is the same...

For Dimitris...

OK

DAVIS Clone