ELECTRONICS: Laird Technologies Inc.’s recently announced its new Q Series Thermostatic Controller for most Thermoelectric Assemblies (TEAs).The Q Series Thermostatic Controller is a microcontroller-based device that adds integrated temperature control to a TEA. The controller functions as a single directional unit that offers heating or cooling temperature control to the device. Products in this series include TC-18-QC-50 and TC-18-QE-50.
Programming of advanced controller options and features are available to meet unique application configurations. All programming is conducted in-house by Laird Technologies Engineering. Features include alarm shutoff, upper and lower temperature limits, upper and lower voltage limits, and tachometer limits.
The temperature set point ranges from -20 to 50C and can be adjusted with an internal or external potentiometer. The controller operates in one of three temperature regulation modes:
- On/Off - Switches the Thermoelectric Module (TEM) output between full power and zero power at the programmed set point and hysteresis.
- PWM - Uses an 8 kHz PWM to control the voltage for the main output.
- Proportional - Uses a variable dc-voltage (a PWM varied voltage filtered with a required external capacitor parallel to the load in order to function) for the main output.
The input power of the controller accommodates a supply voltage ranging from 12 to 58V dc. Outputs power the TEMs and two DC fans from the supply voltage with a maximum available current of 16A and 2A. Additional outputs provide an LED feature that displays the status of the controller. If an error is detected based upon programmed parameters, an alarm is triggered that automatically shuts down the TEA.
Hardware circuit protection guards against reverse polarity and three sensors incorporate an NTC thermistor for closed loop feedback control. Two fan tachometers measure fan speeds.
The Laird Technologies Q Series Thermostatic Controller provides a single directional temperature controller solution for thermal management systems seeking thermostatic control. This device can be used to drive TEAs used in many of the medical diagnostic, analytical instrumentation, photonics laser and electronic enclosure cooling applications.
- Edited by Liz Taurasi