WORKS WITH PELTIER MODULES OR RESISTIVE HEATERS, FANS, AND MORE!

Using a Type "T" thermocouple as a sensor, the Model 5R7-388 temperature controller provides automatic biphase heating and cooling control for Thermoelectric (Peltier effect, or TEC) modules. (If you do not require compatibility with a thermocouple please consider using our similar thermistor based controllers.)

If the cooling or heating function is switched off using the Setup program, these controllers are compatible with  resistive heaters, fans, and many other DC voltage devices that proportionately alter operation based on the amount of power supplied. Adding a diode to the output allows the controller to power a Thermoelectric module in conjunction with a resistive heater (for additional heating power), or other DC driven device. Peltier modules use only the proportional control, but On/Off control can be used instead of proportional for solenoids, relay, heaters, etc.

The user friendly Setup program requires no prior programming experience to establish operation. A command set is provided for qualified personnel to program a software interface or use as an embedded control. The software, its C++ code, and command set documentation are on the accompanying CD. For examples of using this type of command set see our library page, Communications Protocol.

A display is available as a PCB and cable (shown right). The Model 5R6-582 front panel display allows you to see the actual temperature or set the Set Point using 0.1 degrees resolution.

The "H" bridge configuration of the solid state MOSFET output devices allows for the bi-directional flow of current through the thermoelectric modules. Highly efficient N-channel output devices are used for this control mode.

A Pulse Width Modulated controller, or PWM controller, is a type of switched-mode controller. Our PWM controllers use square waves of varying widths and at a high frequency to provide power to the "load" (heater/cooler). Low power dissipation and precision control of the load make this type of temperature controller perferrable to analog controllers.

With peltier modules it is necessary to have a smooth transition between heat and cool modes, especially when controlling the temperature of laser diodes or telecom components. Our controllers provide a smooth transition from one mode to the other.

Compensation can be made for the difference in the efficiency of a peltier module's heat and cool modes.

Once the desired set parameters are established, the PC may be disconnected and the controller becomes a unique, stand alone controller. All parameter settings are retained in non-volatile memory.

Mechanically, the controller's printed circuit board is mounted to a metal bracket that is suitable for either horizontal or vertical orientation. Input and output connections are accessible via eurostyle screw type terminal strips, fast-on terminals, and a 0.100 center connector. ( Mechanical Drawing & Hookup)

The controller is PC programmable via an  "RS232 communications interface". One RS232 COM port on your computer will configure and monitor one controller. The easily accessible communications link permits a variety of operational mode configurations. (Other types of communications, such as I²C communications, can be added to a customized version of the controller.)

Each controller has two sensor inputs. The second sensor input can be used for a sensor or optionally be used for remote set point adjustment using ma or a voltage or a potentiometer based dial.

All sensors used by this controller are Type "T" thermocouples.

 

 


Input Supply Voltage

The Model 5R7-338 is capable of operating from an input supply voltage of 12 through 36 VDC, common to many available thermoelectric modules. However, by supplying load power separately from the controller power, you can use loads, such as thermoelectric modules, that are anywhere from 0 to 36 vdc. The self-contained MOSFET output devices deliver load currents up 25 amperes. At 15A and higher it is recommended that you add a heaetsink to the mounting bracket. You can order the controller with a heatsink by adding "H2" or "H3" to the end of the part number (see heat sink options here). These units will control total load power up to 900 watts.

These controllers will control with a finite temperature resolution of 0.05°C.

OEM Note: To drive down the cost of production units we can custom build for fixed, or selectable, voltages and levels of power, such as fixed 5 VDC at 2 Amperes.

Output Signal

The output signal to the thermoelectric module is Pulse Width Modulated (PWM) at 2700 Hz. Pulse Width Modulation averages the amount of energy provided to the module and reduces the extreme temperature excursions that are experienced with an "on / off" type of control system. This tends to extend the life and reliability of the thermoelectric devices.

Tuning

The controller tuning structure allows designation of a variety of control features. Proportional bandwidth (P) in degrees, Integral reset (I) in repeats per minute, and the Derivative rate (D) in minutes may be configured for P, PI, PD, or PID control. In addition, a deadband control (on/off) with an adjustable hysteresis may be selected. Differential temperature control is possible when two input sensing thermistors are used. The controller can also be used as a variac in whcih a computer set value provides for manual control of the output, either polarity, from 0% to 100% of load power.

Set Temperature Input

The temperature can be set directly through our standard Setup program or other software.

Additional external set temperature input types may be selected. They include a remote set temperature potentiometer, a 0 to 3.3v VDC signal, and a 0 to 20 ma (or 4 to 20 ma) current loop. These secondary inputs are used to define and "map" the secondary input to an adjustable temperature range. Differential set temperature control may also be selected from this configuration menu. All temperatures may be consistently displayed in °C. or °F.

Differential Temperature Control: Differential control is available and is accomplished by selecting the primary set temperature with the second thermistor input and establishing the offset with the computer set temperature. In other words, when using differential control you no longer set the temperature itself from the computer, but rather the offset from the temperature sensed by the second sensor. For example, A +10 degrees offset means the control temperature will always be held at 10 degrees above the temperature being sensed at the second sensor. The control temperature will be the "differential" between Input 2 (the temperature at the second sensor, which becomes a reference temperature) and Input 1 (actual system temperature).

Control Output Modes

Two types of control output modes may be selected for the controllers. This determines the direction of the current flow through the thermoelectric module during the heat cycle. This current flow may be from Wire Point WP1 (+) to Wire Point WP2 (-). Alternatively, this current flow may be reversed from WP2 (+) to WP1 (-) as selected in the configuration menu.

Variac Mode

From the PC you can choose to bypass the controllers internal control algorithms and set the output power to a specific value. There are 511 negative, 0, and 511 positive power values.

Alarms

Several alarm types may be selected. The alarms provide a 5 VDC output at the expansion connector, rated for 25 ma of current. The alarms consist of a "no alarm" function, tracking alarm, and fixed value alarm. Alarm set temperature values are entered in the setup menu. The computer-controlled selection is available for additional embedded controller input/output options. The alarm setup menu also provides for selection of an alarm latching condition. The alarm sensor may be either the control temperature sensor or a secondary thermistor sensor.

Power may be maintained during an alarm condition or the output power may be shut down.  

 
(Notes & Software)

Photo, Mechanical Drawing, and Hookup
 

Temperature Stability

Temperature stability is a function of the resolution of the input temperature signal.  The controller can hold temperature to the finest increment of the input temperature signal.  The controller can resolve temperature changes down to 0.05°C. The stability you achieve depends more on the design of the overall thermal system than on the controller's resolution. These controllers provide DC voltage control with the possibility of stabilizing to better than ±0.1°C in a very well built thermal system.

OEM Note: If you start with the standard controller that has 0.05°C resolution and determine you need a controller with greater resolution for your product, we can design and provide a controller that meets the requirements of your product.

Connections

• This unit requires a DC voltage cable that connects to the controller using two 0.25 inch quick connects (fast tab connections).
• The power connection of the heater or cooler to the relay is also made with the same type of connector as above.

Operating Temperature of the Solid State Relays (SSR, MOSFET)

The relays are mounted to the base of the angle bracket and the bracket acts as a heatsink.

In general it is recommended that the bracket have a heatsink if your system draws 15A or more. Add "HS" to the part number to include a mounted heatsink.

Specific recommendation: The ultimate goal is to cool the Mosfet junction temperature. Measure temperature at the tab of each MOSFET under normal operating conditions. The maximum operating junction temperature is 175°C.  We recommend maintaining tab temperatures at less than 100°C if possible in order to extend the life of the product.

Software

A PC/Windows based console program for configuring the controller comes with the unit, but you can go beyond the program provided and control the temperature controller by means of your own or other software:

• For Programmatic Control
• Programming: Programming the controllers yourself requires an appropriate capability in a programming language (such as Microsoft's Visual Basic or National Instrument's LabView or similar). Device drivers for the controllers are available at Kajei.com. The controller's command set is provided on the software media that accompanies the controller. For more infomation, see our Library page about the Communications Protocol.
  
• Source Code: The C source code for the Setup program is provided on the software media that accompanies the controller.

 

EXAMPLES OF CUSTOMIZATION
Custom Temperature Ranges
Custom or Programmable Voltage/Current
Custom dimensions
Any Additional Circuitry / Electronics on the Same Board
Safety Features / Cutoffs / Fuses / Current Limitting
Fan Control
Custom Alarms
Ruggedized
Uniphase Output
Various Types of Sensors
Rack Mount Versions
and more (inquire)

 

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: The 5R7-388 is generally in stock and can be shipped in 2 to 4 days ARO. Out of stock items may have a 1 to 4 week lead time.

MODEL 5R7-388
  Quantity 01 price: each
   Lower prices are available at higher volume starting at quantity 2.

MODEL 5R7-388 with Heatsink
See heat sink options here.
  5R7-388H3 Quantity 01 price: each (controller with short heatsink)
  5R7-388H2 Quantity 01 price: $ Ask each (controller with tall heatsink)
  Lower prices are available at higher volume starting at quantity 2.

MODEL 5R6-582 Display
  Quantity 01 price: each
  Lower prices are available at higher volume.

• Customization
• We can custom build for fixed, or selectable, voltages and levels of power. We can customize the form factor. We can take a finalized through-hole design to SMT. This is a custom build. We can quote an NRE and per unit price based on your feature set. Email us. Give us an idea of what you are considering and we will work with you to develop the controller's specifications.
• Payment
• Check, wire transfer, VISA, Mastercard, Discover, American Express, Electronic Check, PayPal.
• General Notes on Pricing
• Controllers Only: Prices shown are for the "controllers only". 
• Currency: All prices are $US.