Quote:
Originally Posted by troypiggo
Sorry to resurrect such an old thread, but I'm looking at some dew heater solutions at the moment. I am a bit of an electronics noobie, but recently I successfully soldered my first Jaycar kit as a test run - it's a row of LEDs that indicate the charge level of my 12V battery. But I digress...
Understood Alan's article for the most part and reckon I could do that, but the addenda by Brendan was a little over my head. Could someone put that addenda in lay terms for a dummy like me? I mean, is there a problem if I build it as per the original article, or should I be making the adjustments in the addenda?
Does this mean you could, knowing the dew point, set a temperature somehow on the controller at which the heater would kick in? Any pointers in the right direction for that?
|
Hi Troy.
This circuit can be powered by anything up to around 28 volts but most people use 12 volts.
If you use a voltage higher than 12 Volts you can damage the Mosfets, that's why they use a 12 Volt regulator. It limits the amount of voltage to the gates of the Mosfets. This is stated in the documentation supplied with the kit.
However, if you are using a 12 Volt source, then you do not need the regulator. You can omit it (as it may interfere with the circuit) & just put a link wire as shown in the
diagram.
Hope this helps.
edit:
Oooops forgot to mention that the circuit operates all the time when on at a level set by you. To make it "switch on" at a pre-set temperature would require a comparator circuit...a bit more complicated. You need this circuit "always on" as heat flows from hot to cold...you are constantly losing heat energy to the surrounding air (you not really losing energy but... close enough) & the heat is also flowing out from the optical tube.