Principle of operation
For this thermostat, a resistor is built in the thermostat as a heat generator, and it is structured in such way that the electric current is changed by the external variable resistor, as if applying a bias to the operating temperature of the thermostat to achieve the objective. In other words, if the variable resistor is adjusted in a way to allow a high current, the thermostat operates before reaching the preset temperature, and if the variable resistor is adjusted in a way not to allow a current, the thermostat will operate at the preset temperature.
As a result, the range between the preset temperature and the operating temperature, by the variable resistor allowing maximum current, is the temperature variable range.
The temperature of the generated heat by the built in resistor determines the variable range. Because of such a design, this thermostat is provided with a lead wire for control, in addition to the standard lead wire, resulting a total of three wires.

Caution
This system will not work in an environment where the heat generated inside the case is taken away due to some external effect such as strong wind. Therefore, it is more effective in an application where the heat stays inside, such as a heating mat.
Because of the lead time required for experiments and custom manufacturing, it is not suited to a small lot production.
We will accept purchase orders only if the quantity is 1,000 pieces or more per order.