Components and Design (Cont’d)
I wasn’t able to obtain specific information on the Peltier device used in Monsoon II. However, based on the information that is available (40mm, 12 VDC, 5A, 50W 100% loading) it is safe to assume that the TEC is probably a relatively high-power 40mm unit (24 volts Vmax, 10A Imax, 65° DTmax, and upwards of 150 watts Qmax). Reducing the applied voltage to 12 VDC allows the TEC to operate much more efficiently but also decreases its overall heat pumping capacity.
One of the unique features of the Monsoon II TEC cooler is that the Peltier device is only turned on when needed. When the CPU is idling and when the ambient air temperature is relatively cool, the TEC isn’t needed and the processor is cooled via the heat pipes and fins, just like a traditional HSF. At higher loads and/or when the ambient air temperature is above 25°C, the Monsoon II control module turns on the Peltier device for additional cooling.
The control module (management unit) is designed to mount in a spare 5.25′ drive bay. A multifunction LCD display is mounted in the center of the front panel surrounded by two buttons; one for selecting the color of the display (blue, green, purple, pink, etc.) and the other for selecting °C or °F.
The digital display shows the total run time, incremental run time, CPU temperature (actually the coolers base/cold-plate temperature), and includes an animation of a stick-man digging, which is supposed to represent how hard the processor is working.
Inside the controller are two printed circuit boards (display and control) and there are three connectors on the rear for attaching cables. The connector on the right receives a standard 4-pin Molex for supplying power to the unit. The two connectors on the left attach to the Monsoon II cooler cable, one for power to the Peltier device and the other for fan power and the temperature probe.
The Monsoon II controller comes pre-programmed to maintain a target CPU temperature, which from my testing appears to be 25-26°C. When the CPU (cold plate) temperature is £25°C, the controller turns off the Peltier device and runs the fan in low speed. This insures that the temperature of the CPU socket area never drops below 25°C so there is little chance of condensation forming. As the CPU/base plate temperature increases, the controller will gradually speed up the cooler’s fan and start cycling the Peltier device on and off to maintain the programmed target temperature. Depending on the processor load, the CPU temperature will rise above 25°C unless the ambient air temperature is significantly below 25°C. The Monsoon II control module also contains an audible alarm that will sound if the temperature drops below 15°C or rises above 70°C.
