Patent ID: 8896335

Claim:
An apparatus for controlling a temperature of a device under test, comprising: an adjustable first fluid source configured to input a cold fluid having a first temperature; an adjustable second fluid source configured to input a set point fluid having a second temperature that is substantially the same temperature of a set point temperature of the device and higher than the first temperature; an adjustable third fluid source configured to input a hot fluid having a third temperature higher than the first and second temperatures; a cold line that conveys the cold fluid from the adjustable first fluid source; a set point line that conveys the set point fluid from the adjustable second fluid source; a hot line that conveys the hot fluid from the adjustable third fluid source; a valve configured to discharge an adjustable amount of at least two of the cold fluid, the set point fluid, and the hot fluid into a combined fluid, the valve being located at a junction of the cold line, the set point line and the hot line; a heat sink configured to be in thermal contact with the device, wherein the combined fluid is discharged from the valve to the heat sink and circulates through the heat sink; a first fluid return line; and a second fluid return line, wherein an opening of the valve is controlled to discharge the adjustable amount of at least two of the cold fluid, set point fluid, and hot fluid such that a heat sink temperature compensates for changes in the device temperature and substantially maintains the set point temperature of the device, and after the combined fluid impinges on the heat sink, the valve discharges the combined fluid to the first fluid return line and the second fluid return line such that a portion of the combined fluid returns to the first fluid source via the first fluid return line, and a remaining portion of the combined fluid returns to the second fluid source via the second fluid line.