Philips PM 3210 Operating Manual page 25

time-base sweep.
The output pulse of this oscillator controls the driver
generator.
In positions A, B, ADDED and X-Y the blocking
oscillator is inoperative; the driver generator is then
controlled by the push-button switch.
3. The driver generator, which supplies voltages
required to obtain the different positions of the
diode switch.
THE COMBINATION UNIT
This unit comprises the following circuits.
1. The unblanking circuit which unblanks the c.r.t.
during the sweep of the time-base.
2. The blanking circuit which suppresses the beam
during the switching between channels A and B.
3. The external Z-modulation circuit.
11
. The calibration-voltage generator.
This generator provides a square-wave voltage of 1 V
+1 % at a frequency of about 2.5 kHz.
. Graticule-illumination circuit, which provides a
graticule illumination which is independent of mains-
voltage variations.
. Voltage stabilizer, which keeps the 23 V input voltage
of the converter at a constant value during mains-
voltage and load variations.
The stabilizer provides together with unit 10 (mains-
voltage transformer + rectifier) and the series
regulator on the rear of the instrument, the supply
voltage for the converter.
. Connector unit 6. This unit consists of a square-wave
converter with a frequency of about 18 kHz.
The power pack provides all supply voltages for the
instrument, viz. + and —23 V, + and —95 V, —1600 V
and +8500 V.
Orift-feedback Feedback
Amol. Att.
F.E.T.S.F.
and
Prot.Circ.
and
Prot.Circ.
Drift-feedback
Ampl.
Feedback
Att.
Driver gen. ie Blocking
osc.
CAL,
Time Base