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Easy temperature control idea

QuornSnake

QuornSnake

Hebi Kage
Well, not really an idea, just looking in to building a rheostat style dimmer switch for my UTH and i came across this:
dimmer.jpg


Main reason being id like to try and get a more stable temperature in the viv, the thermostat is fine but the thermometer says its ranging from approx 80f-90f

Ill post results when it arrives.
 
I just read a great article by Clay Davenport about Thermostats vs. Dimmers. Might want to read it if you're considering switching to a Dimmer...They are not accurate temperature control tools and you will have to adjust them as room temperature fluctuates.

What type of thermostat do you have that you are having problems maintaining temperatures with? What type of thermometer are you using?
 
I was thinking about using it together with my thermostat, setting my stat to kick in if it reaches temperatures i think are a little too high. In theory this should work.

Im using a microclimate ministat 100 thermostat and a exo terra digital thermometer. I put the probes right next to each other.
 
I'm confused as to what you are trying to achieve by using a dimmer as well as a thermostat, the thermostat should be good on it's own :shrugs: How exactly are you planning to rig them up together?

Just trying to understand what you're planning :)
 
Plugging the dimmer into the wall socket, plugging the stat in to the dimmer and plugging the uth into the stat.

What im trying to do it get a more steady temp, i.e. set the dimmer to an approx temp and only have the thermostat limit kick in when the temp gets too high. Because it seems to dip too low on the stat alone.
 
The dimmer won't fix that. Dimmers only control the input of electricity, they do not raise or lower the temperature based on room temperature (that's what a proportional thermostat does).

Perhaps you got a faulty thermostat?

It looks like the Microclimate Ministat 100 is an on/off thermostat as opposed to proportional. If you want a steady temperature, you really need a proportional thermostat. Being on/off could be why you're seeing such a large temperature flux.

I would also suggest something digital as opposed to dial.
 
So you're trying to limit the flow of electricity that goes to the thermostat? Because that's what I understand a dimmer will do, it increases or decreases the amount of electric supplied.

To be honest I don't see how that will work, but I'm not an electrician :shrugs:

You say the temp dips too low on the stat alone? How much fluctuation are you actually getting? What's the highest temp reached and the lowest temp reached? When the stat turns off would be about the highest and when it turns on again would be about the lowest.

Edited, TripleMoonsExotic beat me to it :)

I've used the Microclimate mat stats and only get a 3 degree fluctuation :shrugs:
 
I have 2 and they both do about the same.

I see what you mean about the position of the dimmer, so ill put it after the stat, that way the stat gets full power.

The dimmer will lower the voltage going to the mat, therefore lower the heat it puts out.

I think ive made it sound more complicated than it is.

If anyone can point me to a cheap proportional stat then please do, but the way im planning on doing it will be coming to about £25

What im hoping to achieve is:

- heat mat on a dimmer (limiting the heat that the mat can produce, to, lets say 85f)

- then if the room gets warmer and raises the temp in the viv (so it reaches 90f for example) the stat will kick in and drop the temp down.

The only thing this wont cover is the mat getting a bit cooler than ideal. But weighing it up its better to be a bit cooler than a bit too hot.
 
QuornSnake said:
I see what you mean about the position of the dimmer, so ill put it after the stat, that way the stat gets full power.
Click to expand...

It's not about the position of the dimmer. It's that it isn't going to help your situation at all how you think it will because that's not what it's meant to do.

QuornSnake said:
If anyone can point me to a cheap proportional stat then please do, but the way im planning on doing it will be coming to about £25
Click to expand...

Quality isn't cheap. If you want a product that works accurately, you're going to have to pay for it.

Good luck with it either way.
 
I really don't see it working that way at all. Also you didn't say what temps you're getting at the highest and lowest readings?

As TripleMoonsExotic said, if you don't want the slight fluctuation of an on/off stat and you want more accuracy, the you'll probably be better off with a pulse proportional thermostat. Just make sure the thermostat will take low wattage mats, as some of them don't, some are better suited to high wattage ceramics etc.
 
The stat and temp probes should be on top of the middle of the mat, under the substrate, under the warm hide, as that is the hottest place your corn can get to.

If that's not where you've been reading the temp, then that's why you're getting too low a reading, as ambient air temp, like on the side of the tank, will be lower :)
 
Susielea said:
The stat and temp probes should be on top of the middle of the mat, under the substrate, under the warm hide, as that is the hottest place your corn can get to.

If that's not where you've been reading the temp, then that's why you're getting too low a reading, as ambient air temp, like on the side of the tank, will be lower :)
Click to expand...

Thats where they are, but he's in a plastic tub style viv at teh moment until he's big enough for a 3ft one in a few months time, that may be why readings are a little rough.

My other stat is in a viv with my leopard gecko, and thats on top of floor tile, that also may be giving a slightly weird reading.... i blame the fat round probe they give you... would it be too much to ask for a flat one that makes good contact with the mat :awcrap:
 
If the probes are moving around when the snake touches them and that is causing the large fluctuation, I mean 10 degrees is a lot, then you can anchor it down with some blue tac or aquarium sealant, so that it is in contact with the mat all the time, you can do the same thing with the thermometer probe too :)

I can't understand how you're getting such a big high/low difference :confused: I've never had more than a 3 maybe 4 degree difference with those stats. Maybe yours is faulty :shrugs:
 
This combo won't help with fluctuations.

Think of it this way. A thermostat is an on/off switch. That's it. Think of it as a little guy in there watching a thermometer. As soon as it gets below 90 he flips the switch on, and the UTH turns on. As soon as it gets above 90, he flips it off. That's all he does.

A rheostat is easy to think of like a throttle. Imagine you are going down the road at 50% throttle. Say that holds you to 50% speed on flat ground. That's great, but what if you start going uphill? Your speed (temps in our case) goes down. But you can't go any faster because your throttle (rheostat) is set. You need to turn it up to say 60% to maintain speed.

Temperature fluctuations in a tank are usually caused by the substrate's ability to hold heat. In aspen, the temp over the UTH will get up to your thermometer set point, and the thermometer will shut off (on/off switch). But the UTH still has heat, and temps still climb. May reach say 94. Since your aspen doesn't hold heat that well, things start to cool off quickly. Just for #s say 2 degrees a minute. So if you drop below 90, and within a minute the temp drops to 88. UTH is on, but takes another minute to start warming things up. 86. As you can see, an 8 degree temperature fluctuation is easy to achieve.

So say you mix a rheostat in with that. It would have to go wall-thermostat-rheostat to make sure the thermostat gets proper current. What will now happen is the same as above, but your UTH is only operating at say 60%. This means it's going to take longer for your temps to climb back up once the thermostat turns on. It will probably increase your min-max variance unless you have the UTH at 100%. At which point, theres no sense in the rheostat.

Note that the above numbers are made up, and I don't know the ability of aspen to retain heat. But I do know on my tiled tank for leo's, they stay warm longer and my temps are usually +-2 degrees around 90.
 
98xjsport said:
This combo won't help with fluctuations.

Think of it this way. A thermostat is an on/off switch. That's it. Think of it as a little guy in there watching a thermometer. As soon as it gets below 90 he flips the switch on, and the UTH turns on. As soon as it gets above 90, he flips it off. That's all he does.

A rheostat is easy to think of like a throttle. Imagine you are going down the road at 50% throttle. Say that holds you to 50% speed on flat ground. That's great, but what if you start going uphill? Your speed (temps in our case) goes down. But you can't go any faster because your throttle (rheostat) is set. You need to turn it up to say 60% to maintain speed.

Temperature fluctuations in a tank are usually caused by the substrate's ability to hold heat. In aspen, the temp over the UTH will get up to your thermometer set point, and the thermometer will shut off (on/off switch). But the UTH still has heat, and temps still climb. May reach say 94. Since your aspen doesn't hold heat that well, things start to cool off quickly. Just for #s say 2 degrees a minute. So if you drop below 90, and within a minute the temp drops to 88. UTH is on, but takes another minute to start warming things up. 86. As you can see, an 8 degree temperature fluctuation is easy to achieve.

So say you mix a rheostat in with that. It would have to go wall-thermostat-rheostat to make sure the thermostat gets proper current. What will now happen is the same as above, but your UTH is only operating at say 60%. This means it's going to take longer for your temps to climb back up once the thermostat turns on. It will probably increase your min-max variance unless you have the UTH at 100%. At which point, theres no sense in the rheostat.

Note that the above numbers are made up, and I don't know the ability of aspen to retain heat. But I do know on my tiled tank for leo's, they stay warm longer and my temps are usually +-2 degrees around 90.
Click to expand...

I think the bold bit should be "stat" ;)

Nicely explained, that was what I was thinking, (about how the dimmer and thermostat would work), but just couldn't find a way to put it into words, well done and thank you :D
 
I see what u mean jsport.

I suppose it'd only make sense to use this system if the stat is set quite a bit higher than the rheostat average, so it won't fluctuate that often.

Soon tiles u only get a + - of about 2f? Thats pretty good. Is that an on/off stat? If so where do you place the probe? And is it taped down?

Also, am I right in thinking that the fluctuations could be due to the fact probe is made of metal, which retains heat longer than aspen etc. ?

How much is a proportional / pulsing stat? And are they THAT much better?

Cheers
 
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