X-Ray machine Arman 9L5 Repair - tube error.

In the Arman 9L5 X-ray machine, high voltage is applied to the tube with a delay of several seconds. The delay is needed to heat the cathode tube filament heater.

If there is no signal for the end of the delay, no high voltage will be applied to the X-ray tube.

For stability, the delay time is formed by counting the number of pulses generated by the driver on the D8 chip from a sinusoidal voltage of 50 Hertz.

D8 is a high-speed operational amplifier K544UD1A with high input impedance and a differential stage on field-effect transistors. These parameters are needed to ensure the steep edges of the forming pulses.

On some models, the D8 may be K140UD6. This is an operational amplifier with high gain and low input currents. It is also suitable for a pulse shaper at this frequency.

The presence and shape of the pulses can be viewed with an oscilloscope. Pulses should be such as on the waveform.

Operational amplifier D8 - DC modes.
D8 - K140UD6 in a metal microcircuit case.

1 - 0
2 - 12,7
3 - 6,7
4 - 0
5 - 0
6 - 12,4
7 - 25,4
8 - 0