The temperature control of the Peltier elements can be solved by different ways. The simplest control is the two-point control. A threshold value is defined for the start of the cooling or heating function. A so-called hysteresis (dashed in the following diagram) determines the end of the respective function. The result is a relatively inaccurate control, but which is sufficient for many applications (e. g. air conditioning of switch cabinets).
Uwe electronic offers the UETR-MOST-16A controller that has semiconductor relays instead of mechanical relays as an improvement in lifetime. Since the contact points of the relay are no longer oxidized by arcing, the hysteresis can theoretically be reduced to 0.1°C. The hysteresis can be reduced to 0.1°C in theory. In the case of very slow control systems with high heat capacity, precise temperature control is therefore possible with this controller.
PID controlling
Very precise temperature stabilization is achieved by PID controllers with adjustable proportional, integral and differential components. Digital controllers pulsate the voltage supply in the range of seconds to change the effective voltage supply.
As a result, temperature stabilization is possible without large overshoots. This control mode is selected for the highest requirements of temperature accuracy. The Peltier module is also protected with this control, as only slight temperature fluctuations and therefore only very low dynamic linear expansions occur.
Subject to alterations and errors excepted