On / Off Temperature Controllers

On-off temperature controllers (also called signallers), are simple temperature control devices. An optimal temperature is preset and when it's exceeded the output switches off. When the temperature falls below the optimal preset, the output switches on. The output value has only an 'on' or 'off' option, with no middle state.

What are on-off temperature controllers used for?

On-off temperature controllers are used for monitoring purposes in heating environments. They prevent rapid increases in temperature that may cause damage to contactors and valves by cutting off the power. These controllers are often used where there isn't a need for precision temperature control. They are beneficial in applications where the system can't handle continuous interruptions. On-off controllers are found in temperature alarms and thermostats.

Types of on-off temperature controllers

A typical example of an on-off temperature controller is the thermostat in a heating system. If the temperature drops below the preset level, the heating system will switch on, and vice versa. Another example is that of a limit controller. It protects a system against overheating or overcooling by shutting down the power if the temperature exceeds a preset level.