초록 ▼

A control apparatus for controlling the temperature of an environmental chamber within which a device is tested for thermal characteristics employs a pair of control elements connected in cascade. The first element produces a required air temperature in response to a desired temperature and to the t

A control apparatus for controlling the temperature of an environmental chamber within which a device is tested for thermal characteristics employs a pair of control elements connected in cascade. The first element produces a required air temperature in response to a desired temperature and to the temperature of the device; the second produces a temperature set point in response to the required and actual air temperatures. Possible stress on the device is avoided by limiting the range of required air temperature. Response is accelerated by a pass-through circuit, parallel to the first element, which responds to a change in the desired temperature by adding to the required air temperature of value proportional to the change.

대표청구항 ▼

In an environmental test system in which a device under test is contained in an environmental chamber, said environmental chamber including means responsive to a chamber control signal for setting an environmental condition within said chamber, and signal means in said chamber for providing a first

In an environmental test system in which a device under test is contained in an environmental chamber, said environmental chamber including means responsive to a chamber control signal for setting an environmental condition within said chamber, and signal means in said chamber for providing a first signal indicative of the reaction of said device under test to said environmental condition and a second signal indicative of said condition, a control apparatus for generating said chamber control signal, said apparatus comprising: setpoint means for generating a test condition waveform; a first control means connected to said setpoint means and to said chamber for generating a first operating point signal in response to said first signal and to said test condition signal; limit means connected to said first control means and responsive to the magnitude of said first operating point signal for limiting said first operating point signal to a constant magnitude value when said magnitude exceeds a particular limit; and a second control means connected to said limit means and to said chamber for generating said chamber control signal in response to said second signal and to said first operating point signal.