How to make a heat plate that produces temperature Between 70 to 78 degrees Fahrenheit

[Cyberlife]

Hi
Sorry if my English is poor
How to make a heat plate that produces temperature Between 70 to 78 degrees Fahrenheit and work with low voltage and consume little energy.

 

[kubeek]

that is 21-25°C, what is the ambient temperature? How big is the plate supposed to be? How well is it isolated from the ambient? Will it be cooling or heating?

 

[Cyberlife]

that is 21-25°C, what is the ambient temperature? How big is the plate supposed to be? How well is it isolated from the ambient? Will it be cooling or heating?

yes, that is 21-25°C or 21-28°C
I want to use this plates To heating my bird's nest or when bird's sitting on the plate in my home garage in winter, I think the garage temperature in winter is between 3 to -6 ° C
the Plate size is 15 x 10 cm

 

[large_ghostman]

A couple of these run from 12V, they have a thermistor built in, so do a comparator circuit to drive a relay.
**broken link removed**

Actually use a Mosfet as it will probably cause relay chatter, even with some hysteresis.

 

[dr pepper]

You might even be able to do that low temp with vehicle headlight bulbs under the plate, depends on what you mean by low energy.

 

[large_ghostman]

You might even be able to do that low temp with vehicle headlight bulbs under the plate, depends on what you mean by low energy.

Bulbs suck for reliability, but nice and easy and very cheap.

 

[MikeMl]

Bulbs suck for reliability, ....

Not if they are operated as heaters, where they never do more than just glow red <90% of rated voltage)

 

[ericgibbs]

Not if they are operated as heaters, where they never do more than just glow red <90% of rated voltage)

I have also used 'under run' tungsten lamps as heaters over long periods of time, without any problems.

 

[chemelec]

I make my own heaters using 30 AWG Nichrome wire.

It has a Resistance of 6.1 Ohms per foot, so it is easy enough to calculate current draw.
And if a Low Resistance, Power Type of PTC Thermister was Connected in Series with it, It would Self-Regulate the Temperature.

 

[large_ghostman]

Not if they are operated as heaters, where they never do more than just glow red <90% of rated voltage)

How would you drop 23V from uk mains? or do you simply put a smaller Wattage bulb in series?

 

[alec_t]

You'd put a higher wattage (i.e. lower resistance) bulb in series.