We offer a circuit package manufactured to our design specification.

Note: DC input lead-wire and female DC receptacle are not attached to terminal panel in this photo

Base circuit consists of a small circuit board, measuring about 70 mm square. This circuit board has a miniature terminal strip at one end, with terminals that can be opened/closed using a small flat head screw driver.

This terminal strip allows three sets of connections:

DC power in (which can be ordered with attached electrical lead, plus standard female DC receptacle)

DC power out to TEC Module(s)

DC power out to cooling fan(s)

There are also two separately-potted connections:

To NTC temperature sensor

To red LED display and operator control panel

The female DC receptacle, the NTC sensor, and the LED display/control housing are all connected via 40 cm wire leads. This allows the base circuit board to be mounted at one location (with TEC module and fan leads connected to it), and the DC power-in receptacle, the NTC temperature sensor, and the LED display/control panel to be individually located as required by your application.

The circuit can handle 12 VDC input up to 10 amps (although the standard female DC receptacle is designed to take only up to 6 amps -- above that, you must use screw-type attachment terminals). The temperature sensing range for the system is -20 C to +85 C, with temperature displayed via red LED in 0.5 degree increments.

The system has built-in switching capability between Fahrenheit and Centigrade temperature display, via control panel settings.

System allows user to select "set-point" display mode using one switch, and then set a cooling target set point using "up" and "down" scroll buttons. At second click of the set mode switch, the display reverts to actual temperature at the NTC probe tip.

If target set-point is below current sensed temperature, a relay closes, and the power to the TEC module is switched "on," allowing the TEC module to chill the target. Once set-point is reached, the relay opens, and power to the TEC module is switched off.

Power output to the cooling fans is continuous.

The NTC sensor will work properly in air, or in non-corrosive liquids, and is attached to a small brass mounting ring. Because of how this mounting lip is configured, this sensor cannot accurately display the temperature of a solid object to which the mounting ring is attached.

For bulk orders of 50 units or more, customer can specify desired length of each remote lead-wire.

Individual units of the single-set point control circuit are offered at US $39 each, with significant discounts available for bulk orders.

We also offer an advanced version of this circuit. This version allows both a low target set-point temperature, and a high set-point temperature to be established -- and the circuit then controls to keep the actual temperature between the two set-points. It does this via bi-polar DC output capability to the TEC module connection. When actual temperature is below the low target set-point, the TEC module operates in heating mode. When actual temperature is above the high target set-point, the TEC module operates in cooling mode. When sensed actual temperature is in-between the two target set-points, there is no output power to the TEC module(s). DC output to cooling fan(s) is only energized when TEC module(s) are in cooling mode.

Note: DC input lead-wire and female DC receptacle are not attached to terminal panel in this photo.

Individual units of this dual-set-point, bi-polar output circuit are offered at US $52 each, with significant discounts available for bulk orders.

More details about these circuits may be obtained by down-loading the following operating instructions, in PDF format.

We also have a limited number of "breadboard" style control circuits -- in which LED display and control switches are mounted directly on the circuit board, which measures about 100 mm x 60 mm. Only the NTC sensor and DC power in receptacles are mounted on remote leads.

While they last, these "breadboard" versions are available for US $25 each -- or US $20 each, if purchased with an advanced component familiarization kit.