DIY Rheostat (dimmer) for temp control

[JD Constriction]

The prebuilt dimmers (e.g. walmart $10 mentioned above) can goto one or more devices if you plug in an extension cord.

The real limitation with the walmart model is that you can only have so many devices hooked up to it before you overload the dimmer (up to 300w worth).

For about the same money as the pre-built model you can build your own that will handle twice as much wattage (600w).

Really the walmart model is best for most small applications but I like to build things rather than buy sometimes. That and I wanted a dimmer with a ground plug for my 1500w ranco on/off thermostat.

For what you want you would need a thermostat (on/off or proportional) to shut the heat off at a certain temp and turn it back on again when it cools off. The dimmer basically just keeps the same temp difference.....not the same temp.

So if you have an 80 degree room and set the dimmer so that the hot spot is 90 degrees the dimmer essentially is set to +10 degrees.

So if the room heats up to 85 degrees then the hot spot will change to approximately 95 degrees if you don't change anything on the dimmer....same +10 degrees

Hope that makes sense

I've been trying to understand this for a while now and still now 100% on this. At the moment I have my heating sources on a dimmer, if i see a low temp, i turn it up, if I see a high temp in the tank, i turn them down. So essentially this is all he that is being accomplished in this thread is the construction of a dimmer for more then one light.

Now is their a way I could have my heat sources to heat the tank to a certain temperature and then stop? Just like on my fish tank, heater turns on if temp drops below 24 and turns off if tank is above 25, is this acheivable for a BP tank?

[ride_gnu]

The prebuilt dimmers (e.g. walmart $10 mentioned above) can goto one or more devices if you plug in an extension cord.

The real limitation with the walmart model is that you can only have so many devices hooked up to it before you overload the dimmer (up to 300w worth).

For about the same money as the pre-built model you can build your own that will handle twice as much wattage (600w).

Really the walmart model is best for most small applications but I like to build things rather than buy sometimes. That and I wanted a dimmer with a ground plug for my 1500w ranco on/off thermostat.

For what you want you would need a thermostat (on/off or proportional) to shut the heat off at a certain temp and turn it back on again when it cools off. The dimmer basically just keeps the same temp difference.....not the same temp.

So if you have an 80 degree room and set the dimmer so that the hot spot is 90 degrees the dimmer essentially is set to +10 degrees.

So if the room heats up to 85 degrees then the hot spot will change to approximately 95 degrees if you don't change anything on the dimmer....same +10 degrees

Hope that makes sense

Makes perfect sense, dimmers change the heat but need to be contorlled by you. What I am looking for is a "Set it and forget it thing" I currently have 2 dimmers from home depot, one for hot side and one for cold side. They work fine, but for instance when I go to sleep at night, by body heat can change the temperature in the room to at least 4 degrees higher, thus increasing the tempertaure in the tank 4 degrees high, just as you said. What I was looking for is something that will keep a constant temperture in the tank no mattter the temperture in the room so if I set it at 82 and my room increase 10 degrees i wont get a 92 degree, I hope this is understandable.