TC-720

FEATURES

• USB Connectivity
• Control board, keypad and display housed in a durable metal enclosure provide a complete temperature control solution
• Single or dual power supply configurations allow a wide range of output voltages (power supply(s) not included–order separately per application)
• Single power supply configuration: ≥12 VDC, ≤36 VDC input, powering both controller and TE device
• Dual power supply configuration: ≥12 VDC, ≤36 VDC at 150 mA minimum for controller circuitry ≥0 VDC, ≤36 VDC for TE device
• Maximum output current: 20 A combined TE device and alarm current (Note: controller does have software controlled over-current protection, but does not have internal fuse protection)
• Bipolar (heat and cool), cool-only, or heat-only control modes, software selectable
• Temperature control range: between -60 °C to +199 °C in various ranges depending on the thermistor used. -20 °C to +100 °C using the MP-3193 thermistor supplied with the controller. See product manual “MAIN FEATURES” for temperature ranges based on thermistor type.
• Wide variety of pre-programmed sensors; user-programmable sensor can be used
• Optional secondary sensor input for sensing alarm conditions
• Two available alarm outputs, capable of sinking up to 2 A each, for triggering alarms based on the primary (control) sensor and/or secondary sensor
• Fan speed control
• Ramp/Soak Program
• Energy-saving Proportinal + Deaband control mode allows the control to shut off output power where no cooling or heating is required; gradually applies cooling/heating only when needed.
• Best-case control stability ±0.01 °C (when controlling a cold plate)
• Proportional (P) bandwidth adjustment: 0.5 °C to 100.0 °C
• Integral gain (I) adjustment: 0.00 to 10.00 repeats per minute
• Derivative gain (D) adjustment: 0.00 to 10.00 cycles per minute
• Output: square wave, 337 Hz, pulse-width modulated, with soft start
• Analog proportional output signal for controlling programmable linear power supplies
• Operating temperature range (non-condensing, total combined alarm and load current):  Minimum: 0 °C, Maximum: 45 °C
• Built-in keypad can be used to program most of the controller’s parameters by way of easy to understand options
• Computer programmable via USB communication; includes software and command set
• RoHS compliant

APPLICATION
The TC-720 is a bipolar, heat and cool, thermoelectric temperature controller capable of controlling up to 36 volts and 20 amps. One standard thermistor, model MP-3193, is included. A second sensor can be attached for monitoring and alarm purposes. The controller is housed in a die-cast aluminum box and incorporates a keypad and a liquid-crystal display. The display allows the user to monitor the sensor temperature, power output level, and menu settings. The integrated keypad accesses an easy-to-use menu system, allowing the user to adjust all of the basic controller parameters such as the set temperature, tuning parameters, and alarm parameters.  The controller can also be connected to a computer via USB for more advanced program control as well as data graphing and data logging, using the supplied software.

All of the controller parameters, including some of the advanced parameters not adjustable through the onboard menu, can be adjusted using this software. The command set for the controller is also provided to allow the creation of custom software applications. The controller is shipped as the basic control circuit mounted on an aluminum panel. One standard thermistor (model MP-3193) and a software CD are included. The software is shipped as a stand-alone program, but the LabVIEW source code for that program (version 2018 and higher) is also available upon request. A sample read and write command programmed in Python (2.7) is also available for download from the SOFTWARE tab on this web page.

The TC-720 controller regulates the output power to the TE device (or DC heater) using pulse-width modulation (PWM). By choosing the appropriate external power supply(s), the controller can control loads from 0 to ≤36 VDC via pulse-width modulation with the on-board power transistors. (When controlling voltages of less than 12 volts, a small, 12V, 150 mA power supply must be used to power the controller’s microprocessor.)

Two alarm outputs, each capable of controlling up to 2 A each, can be used to control other loads such as pumps, fans and resistive heaters, further enhancing the controller’s capabilities. In addition, the Alarm 1 output can be reconfigured for fan speed control. Used with an appropriate fan, the controller can increase or decrease the fan speed only as needed to help minimize fan noise.

The controller has a built-in Ramp/Soak Program. It provides up to 8 individual ramp + soak steps, and each step can be repeated as many times as needed. The program allows for looping of a sequence of steps as well.

The Proportional + Deadband control mode allows the controller to shut off output power within a given temperature range. It can gradually increase power for cooling or heating as the temperature goes outside that range. This provides for economically operation of the cooler by minimizing the power consumed by the cooler when cooling or heating is not required.

If a true linear-output control system is desired, the TC-720 can be used as the control head for controlling high-power, linear-output supplies. Some of these linear output supplies are available as basic switching power supplies, allowing the user to create a relatively low cost linear control system which generates much less waste heat when compared to a typical linear system. The linear output eliminates the PWM switching and is useful for Photo Multiplier Tube (PMT) coolers and other applications that are highly sensitive to electronic noise.

The TC-720 OEM is also available. This is a basic version of the controller for Original Equipment Manufacturers (OEM’s) as a component in a system where the display, keypad, and box cover are not needed. The controller is shipped only as the basic control circuit PCB mounted on an aluminum panel.