Re: Redundant Temp Controls?
maybe i should look into temp limits and make a limit relay combo that would cut power to the stat or heat tape! i could be rich! lol one dime at a time lol all kidding aside i'll check out some limits and see what i can come up with, off the top of my head about 20 bucks in parts and some wire should do it. maybe less...
vaughn
Re: Redundant Temp Controls?
Quote:
Originally Posted by kavmon
maybe i should look into temp limits and make a limit relay combo that would cut power to the stat or heat tape! i could be rich! lol one dime at a time lol all kidding aside i'll check out some limits and see what i can come up with, off the top of my head about 20 bucks in parts and some wire should do it. maybe less...
vaughn
How would that work? I know NOTHING about electric except not to stick paper clips in the electrical outlets (learned that the hard way). :rolleye2:
Re: Redundant Temp Controls?
basically you find a temp limit that opens on rise. most limits have fixed temp settings like designed to open at 110f for example. some have adjustable settings. you would wire this either on the power to the stat or on the power wires to the flexwatt. basically the limit will open on high temp and stop flow of current to stat or flex. next time i'm at the parts store i'll poke around. a limit similiar to this one would work
http://americanhvacparts.com/Merchan...ry_Code=fl-tdf this one closes on temp rise, one that opens the circuit on temp rise would be easier to install and wire in. i can get those for around 10 bucks.
vaughn
Re: Redundant Temp Controls?
Interesting stuff. I think anything that will work is worth the effort and money.
Re: Redundant Temp Controls?
The way you can self build a circuit is fairly simple. What you do is you take a temperature probe which is basically a thyristor in a protective housing. Youl could actually probably just get a bare thyristor and enclose it in some heat shrink. This would work since we won't be exposing it to extreme temperatures.
The thyristor is basically a resistor which varies resistance based on temperature. What you do is put a voltage on this and feed it into an Operational Amplifier (Op-Amp) circuit hooked up as a comparator. On the other input of the op-amp would be a trimpot wich you would set as a trip point. The output of the op-amp would go to a power transistor wich would activate/deactivate a relay with sufficient current capacity to handle up to 5A. (I think the flexwatt uses 1.5A if I recall correctly)
Once it's hooked up, you would adjust the variable resistor to "set" the trip point where the relay would be de-activated.
Dang, now you got me thinking. Perhaps I can build this and just buy one temperature controller! A better alternative would be to use a high power transistor as an on/off switch so that a mechanical relay would be un-necessary.
Really, when I think about it, what you're paying for in these temperature controllers is a digital display and easy adjustment of it's trip point. But for this application, all we have to do is set it once, and just use our cheap Acu-Rite thermometers to gague temperature.
I'll look into this...
Re: Redundant Temp Controls?
i will still use my helixs' on all my racks! i was mainly just thinking of a high limit for safety. using a line voltage limit which is basically a thermal safety as a backup. i'm going to sell these to jamie and cash in big time!!! lol
vaughn
Re: Redundant Temp Controls?
Quote:
Originally Posted by kavmon
i will still use my helixs' on all my racks! i was mainly just thinking of a high limit for safety. using a line voltage limit which is basically a thermal safety as a backup. i'm going to sell these to jamie and cash in big time!!! lol
vaughn
Hahah..Sign me up for 12 of them!!
