Heat unit integrator for X-ray tubes

摘要

Apparatus to indicate the temperature of an X-ray tube target includes an analog storage circuit to simulate the heat energy stored. Input signals representing the current and the voltage of the electron beam in the tube are multiplied to give a signal representing the instantaneous power input. The power signal is integrated in the storage circuit to give a temperature signal representing the total heat input. The temperature signal is dissipated by a cooling curve circuit representing the heat loss with time. An indicator reads the temperature signal. PPInput voltage and current signals are processed to refer them to ground before multiplication. The current signal is corrected to set its zero value. The voltage signal derived from a transformer primary is corrected for transformer regulation. To eliminate spurious inputs the power signal is gated to the storage circuit only when a measured current is flowing. Multiple storage circuits indicating a number of tubes remember the temperature of their own targets while the power signal and the temperature indicator are being used with another storage circuit.