Composition and Operation Principle
3-2
Fig. 3-2 System Operation Principle
a) Power Supply and Power-On/Off Circuit
The battery module is sent to the inversion module through the capacitance storage
module, and the power supply is sent from the battery module to the power supply
module (. When the power supply is connected, the device is in
OFF state. Press the
console
button, and the console will send a power-up command to the main
unit, and the whole unit is in the standby state.
b) High Voltage Generation and Control
When the device is on, the battery module is sent to the inversion module through the
capacitance storage module. When the panel sends an exposure command, the
inversion module starts to work. The output high-frequency square wave is loaded to the
high-voltage oil tank to generate DC high voltage. The voltage sampling circuit of the
X-ray source component will feedback the sampled signals to the PWM drive module,
which generates real-time control pulse width modulating signals to adjust the output
high-voltage, so as to obtain stable DC high voltage.
c) X-ray Tube Filament Heating Principle
The device uses high-frequency PWM (pulse width modulation) AC voltage to heat up
the filament. When different combination of kV and mA is selected, the control program
outputs corresponding filament data to control signals via the A/D conversion circuit.
The signal controls the filament to heat up the inverter and generate pulse width
modulation high-frequency voltage, which excites the filament to heat up.