Energy Matters Forums

[Pepitapuss]

Thanks for the adulations, troppo. I have been busy today--replaced my electronic temp.switch module (which worked beautifully & precisely) with the Jaycar 50deg.C thermo switch & was not happy with the results. The fans now switch on at 37-40deg. which is too early I think? Also it has almost no hysteresis & switches on & off every few seconds. It should have a snap action, but hisses & growls at switch-on as if arcing ?? yet it is only switching 50-60mA. I may have a crook one, so will try another tomorrow.

[troppo]

Thanks for the update Pepitapuss. Will await your outcome as I'm not as sure about electronic fiddling as you. Did see some 50 degree switches on eBay for some cents.

[Pepitapuss]

Attached is the circuit diagram for my skylight. Of course, one can vary things to suit their particular situation. I removed the electronic fan controller & fitted the Jaycar thermostatic 50deg. switch (the first one was faulty !)It now switches on at 44deg. Will wait till summer to check it's operation as there is not enough heat generated this time of the year. My concern , during bench tests, is the lack of hysteresis (differential) ; the fans switch on & off in rapid succession.

Troppo: I spoke recently to Branko of Oatley Electronics. He indicated that he would "throw in" the fans for free with the solar kit. This is one reason I used 4 fans-Igot them cheap. Also as a series chain, the current is the same weather you use one or four fans. Although the fan has 0.13A written on it, the actual current draw is 0.06A at 12v.

Circuit notes
All 4 led arrays & the temp. switches to be attached using thermal paste
Zener diodes allow one green led to remain "on" if the other fails
If the 70deg. switch opens, the red led will illuminate, & power to the arrays is reduced. Most likely cause is an open cct. fan

[Pepitapuss]

Will try again to attach the diagram!!

solar skylight cct..pdf

(47.2 KiB) Downloaded 361 times

[Pepitapuss]

There is an error in my diagram.
S3 switch should be NO - normally open contacts.

[Pepitapuss]

Yet another try at attaching my diagram !!!

[Pepitapuss]

Can't win !! There is still an error in my diagram: this is how it should be:

S2 -- Thermostatic switch 70deg.C - NC
S3 -- Thermostatic switch 50deg.C - NO

[Stella365]

I have had this for a few years now and it has been working like a charm.