This is a teardown of a complete x-ray system, with control panel, x-ray head with high voltage transformer and collimator. The Philips Practix system is a mobile system, usually mounted on a trolley, with the x-ray head on a separate arm assembly. It has a large and small focus fixed anode X-ray tube, the maximum ratings are 100 kV and 25 mA. The change between large and small focal point, is done by mechanical switching inside the tube.
If you want to see more x-ray equipment teardowns, you should check out these systems. Philips Medio 50 kW CP-H X-ray Control Desk Teardown. 50 kW Sedecal SHF-530 X-ray High Voltage Generator Inverter Teardown. Showa SP-103 Standalone X-ray Head Teardown. Siemens Polyphos 30 X-RAY Head 125kV Teardown (Part 1 of 3) or GE AMX-II, mobile 110kV X-RAY system teardown.
Philips Practix X-ray Control Panel
The Philips Practix system has three cables attached to the control panel. One for powering the high voltage transformer in the head, one for lighting in the collimator and a third cable for the double actuating switch. The control panel has settings for voltage and current, marked to the large or small focal setting. Voltage can be fine adjusted to suit the line voltage fluctuations at the site of use. The timer has 21 steps from 0.04 seconds to 5 seconds exposure time.
Inside the Philips Practix control panel
The inside of the control panel reveals that it is divided into two major separate circuits. Everything with gray wires is for mains power to the high voltage transformer. Almost everything else with a colored wire is for the timer circuit. There is no programmable parts, the only complex part is a single vacuum tube used in the timing circuit. Everything else is resistors, diodes and capacitors. The large black transformer inside the control panel is used for voltage adjustment, related to mains power fluctuations. A cam wheel on the kv / mA / aperture selector is used to switch between large and small focal point. This switch powers an actuator inside the x-ray head, which turns the cathode of the x-ray tube, for switching focal mode.
Inside the Philips Practix x-ray head
Inside the x-ray head enclosure, there is a few things going on, on the outside of the shell. A vacuum / expansion chamber, makes it possible the oil to expand from excessive transformer heating. A single end switch is used to detect if the brass knob in the middle is extended too far. The brown solenoid is the actuator for changing focal point. Various resistors are most likely used fail safe wiring termination, that a certain resistance in the circuitry is needed for correct function, else it will fail and not operate.
The x-ray tube is marked 57403 and 62220. The first number is likely the tube type number, but it was not possible to locate a datasheet on it. 62220 refers to the international standard for x-ray medical devices. The high voltage transformer is purely AC, there is no diodes present in the tank. It consists of two windings, most likely midpoint grounded for easier insulation against two times 50kV, instead of full 100kV. Midpoint grounding also makes it easier to do current measurements across a shunt resistor placed at near ground level voltages.