Thermostat or rheostat???

[houdini1]

I need to order one tonight and I was wondering what the difference was and which is better? What do you all use for your leos? Thanks in advance!!!!
Kristy

[hhmoore]

The difference is that a rheostat regulates the amount of power going to a device. Control is generally by a dial or slide lever, and goes from a minimum/off position to full power. There are two problems with rheostats - how much of a problem they are will depend on your setup - 1) you may have to mess with it a bit to get the temps where you want them, and 2) changes in ambient/room temperature will impact the enclosure temps.
Thermostats control temperature through the use of a temperature probe placed in the enclosure. They can be on/off (when the desired temp is reached, the heating device turns off...depending on the set up, you can get a lot of fluctuation) or proportional (power to the device is regulated to prevent large fluctuations - the closer it gets to the desired temp, the less power is applied).
Both devices are good, as long as you understand their limitations. Be advised that many of the cheaper thermostats are relatively inaccurate, and some are prone to failures.

[dragonflyreptiles]

Great explanation Harald, I have a hard time getting my point across on the rheo/thermo comparison!

[NiCoLe L RuSSeLL]

Rheostats are generally used for mats...or should be. I have Kanes heat mats in my herp room and they utiliz the kanes rheos to bring the surface temp down a few notches. Think of them as "dimmers" for heat sources.
I also have some thermostats but I haven't used them since I moved and built a thermo regulated room for the animals.