Mini-thermostat

About the device in general

With size only 35x20 mm the device senses the temperature with a simple diode and switches on and off systems depending on adjustable threshold level (threshold themperature). It uses comparator and a single transistor to power 12V output devices. For applications which require powerful output a relay can be connected to the output. The precision of the device is several degrees. The temperature can be adjusted in range 5- 50 degrees Celsius. The device has one LED diode to indicate on/off mode.
With slight modification (only change the place of 2 elements) this device can be adjusted to sense low temperatures from 0 to -30 degrees Celsius.

The sensing area is relatively small 1 mm sq. The device requires stable 12V supply and consumes less than 20mA in a stand by mode. The consumption rises according to the connected output devices.

The example is demonstrating how the device can power small 12V fun (0.11A consumption). In this case the consumption will be around 150mA, where the fun is on.

Usability