Temperature Controllers 5R7-001 & 5C7-550
Model 5C7-550

Model 5C7-550A

Summary Overview
Specifications (Features)
Implementation Notes


The Model 5C7-550 series is an economical, open board temperature controller especially designed to operate thermoelectric (Peltier effect) modules. This controller will provide temperature control of thermoelectric modules up to 350 watts (28vdc X 12.5 amps = 350 watts). They use a TR67 Series temperature sensor for a temperature range of -20°C to 100°C, or a TR104 Series temperature sensor for a temperature range of 0°C to 150°C. The sensor selection is made via a PCB mounted dip switch.  

The Model 5C7-551 remote digital temperature display (shown above left) is compatible with the Model 5C7-550. The 5C7-551 is provided as two separate pieces: a PCB, ribbon cable. Up and down buttons are used to set the Set Point temperature, and set the temperature scale (units) of Celsius or Fahrenheit. Normal display mode shows the actual temperature read from the control sensor. Displayability is 0.1 for temperatures from 0.0 to 99.9 degrees, and otherwise is an integer value. You can also order the optional P/N 5C7-553 for the mounting plate..

The Model 5C7-550A is an optional version of the controller that includes a remote set temperature adjust dial (shown above right). The dial is provided as two separate pieces: a potentiometer that has leads and a connector, and an adhesive dial scale decal. (You can also use the optional Model 5C7-551 to view the actual temperature while using the potentiometer based dial to set the Set Point. In this combination with the 5C7-550A the 5C7-551 is only used to display the actual temperature.)

The controller contains a solid state “H” bridge. This provides bipolar (BI-directional, automatically heating and cooling as needed) control for one or more independent TE modules for both cooling and heating applications. With appropriate diodes, it can be used in conjunction with auxiliary or supplemental resistive heaters. The control of the “H” bridge is designed to provide a seamless transition between heating and cooling. (no dead spot in the control function during transition between heating and cooling)

The controller utilizes Pulse Width Modulation (PWM) to control the power level in the thermoelectric module. The base frequency is 1.0kHz. The output power resolution is one of ± 250 steps in the load circuit control.

The controller provides an indication of the heat or cool operation mode. A Green LED is used to indicate a heating mode. A Blue LED is used to indicate a cooling mode.

Both the Green and Blue LED being on indicate an open sensor. The controller load circuit (output power) is off when there is an open sensor.

This controller was designed with a proportional and integral control algorithm to provide the most precise control at the most economical cost. The proportional bandwidth is adjustable from 1.0°C to 16°C and the integral rate is adjustable from 0 to 2.55 repeats per minute. These adjustments permit optimizing individual thermal systems. In a well designed thermal system end point control can be ± 0.1°C.

The controller is capable of providing up to 12.5 amps of current for modules rated 3 through 28 volts dc with an ambient temperature of 0°C to +50°C. (refer to mounting instructions)

The controller will operate with a single power supply over the range of 6vdc to 28vdc. If the TE modules require lower voltages, then two supplies are required. One supply for the load 3vdc to 28vdc and one for the control circuit 6vdc to 28vdc (the control circuit will draw less than 100ma).

The controller electronics have a set point stability of < ±0.1°C after one hour of stabilization at 25°C ambient.

The controller has a temperature resolution of approximately 0.1°C. In an optimal thermal system, this will provide an end point control of up to approximately ±0.2°C, or slightly better. To achieve this control requires that the thermal system be well designed, the control sensor be correctly located, and the system be optimally tuned. When selecting the temperature sensor location, we suggest that the sensor be located thermally close to the working side of the TE module. Minimum delay in the temperature sensor seeing the temperature change in the TE Module temperature is preferred. 

Mechanical Specifications

Note: For a small but intelligent TEC controller with either heat only or automatic bi-phase heat and cool, consider a customized version of a 5R7-001 Series controller. For an NRE, we can provide custom, PC compatible controllers with a much smaller footprint than our standard controllers. Interfaces include RS485, RS232, and I2C. The interface is used to set up the controller or to monitor the temperature. Otherwise, a configured controller can run standalone.

Full featured / Low Cost.

Implementation Notes

Mechanical Specifications

For general information about power supplies see our Library page: Power Supply Notes.

MULTIPLE SET POINTS: Since the temperature is set using a potentiometer, and the heat and cool mode is determined by a jumper, it is relatively easy to make a circuit that allows you to easily switch the Model 5C7-550A between two or more temperature settings.



Note: Prices shown are for the controllers only.  Sensors, TE modules and power supplies may be available but are not included in the controller pricing.

Lead Time: Generally 2 to 4 days ARO. Out of stock items may have a 1 to 3 week lead time.

Click here for TR67 Series Sensor Housings and Prices (-20°C to 100°C Range)
Click here for TR104 Series Sensor Housings and Prices (0°C to 150°C Range)

Model 5C7-550 Temperature Controller

   Lower prices are available at higher volume.

Model 5C7-550A Temperature Controller with Remote Potentiometer

   Lower prices are available at higher volume.

Model 5C7-551 Front Panel PCB
Note: Does not include metal face plate or label.
You can use this with the Model 5C7-550 controller.
You can use this with the Model 5C7-550A, but only if you unplug the potentiometer based dial.

   Lower prices are available at higher volume.

P/N 5C7-553 Mounting Plate (for the Front Panel PCB)
Note: Does not include label.

   Lower prices are available at higher volume.


DC Load Temperature Controllers for TEC, peltier modules, fans, or resistive heaters, etc. Proportional & On/Off control.

Descriptive Indexes and Searches

SKU  Volts(v)  Amperes(A)  °C
5C7-195 1-28v 10A -40-150°

5R7-001 0-36v 25A -50-300°
5R7-002 0-36v 25A -50-300°

5R7-388 0-36v 25A -200-400°

5C7-582 9-36v 28A+ -50-300°

5R7-570 3-28v 12.5A -20-150°

5R7-350 0-24v 7.5A -20-100°
5R7-347 0-24v 7.5A 0-120°