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5 . 6 -2
UNIT DESCRIPTIONS
To reduce the switching losses in
V1019, a dV/dt limiter, often called
“snubber", is used. C1021 decreases
the dV/dt of the collector voltage of
V1019 during switching off, as the
current to the transistor can pass
during a certain time through C1021.
This slowing down of the collector
voltage will reduce the switching
losses during switching off. During
the ON cycle, the energy in C1021 is
transferred to L1006 and the
capacitor is discharged. During the
OFF cycle, the energy in L1006 is
transferred to C1018 and during the
next ON cycle, the energy in C1018 is
delivered to the transformer. In that
way, no energy is wasted. As a
consequence of this system, the
voltage at the transformer is slightly
increased during the first part of the
ON cycle, but this has no
disadvantages.
Voltage regulation takes place by varying the control voltage from R1046 to the gate of V1014. A
more positive voltage will cause a smaller peak current through the transformer and this results in
smaller output voltages. The converter frequency can be 20 to 50 kHz. This depends on the mains
voltage and the load of the power supply. The lower the mains voltage, the lower the frequency. A
lower load means a higher frequency. R1018 compensates for gate-cathode voltage variations of
V1014 due to the temperature.
Line trigger circuit
For triggering purposes, a sinusoidal signal at the mains frequency is available. Of course there will
be no LINE signal if the mains voltage is DC.
A small signal is picked up with capacitors C1002, C1003, C1004 and C1006 and amplified in N1046.
This results in output signal at pin 1. This circuit provides a sine-wave with low distortion and with an
amplitude of 3 to 8 V, depending on the mains voltage.
Diagram 2
Diagram 2 comprises the following circuit parts:
- trace rotation control
- fan control
- illumination control
- EHT converter
Trace rotation control
To supply the trace rotation coil, of which the resistance is about 200 Q, a voltage of -10 V to +10 V
is created in amplifier V1146-1147. Control takes place via a part of N1101 by means of the signal
DAC3 which can be 1 to 10 V, together with the signal DAC0 with a level between 1 and 3V. The
signals DAC3 and DAC0 originate from the microprocessor unit A3.
Fan control
The speed the cooling fan depends on the temperature in the oscilloscope. This temperature is
measured at the microprocessor unit A3 by a NTC resistor. The microprocessor generates the signal
DAC1 with a level of about 1.7 to 4 V. The fan is supplied by amplifier V1148 which is controlled by
this signal. The output from the amplifier is a DC voltage of -10 to +10 V.
Figure 5.6
Timing diagram converter circuit
Summary of Contents for PM3082
Page 34: ...DESCRIPTIONS 3 1 ST8235A 970415 ...
Page 35: ...DESCRIPTIONS r _A1 SIGNAL UNIT TRIGGERING ...
Page 36: ...3 1 TIME BASES ST8235A 970415 ...
Page 37: ...3 2 DESCRIPTIONS ST82358 97041S ...
Page 38: ...XYSW ...
Page 79: ...5 1 22 UNIT DESCRIPTIONS Lay out 2 Small component side of signal unit A1 ...
Page 93: ...5 1 33 09001 2 01201 3 01201 5 C 1 O 6 0 T 10n A1 Diagram 1 Attenuator CH 1 PM3094 PM3092 ...
Page 96: ...5 1 34 UNIT DESCRIPTIONS 09001 17 A1 Diagram 2 Attenuator CH 2 PM3094 PM3092 ...
Page 99: ...5 1 35 X I STB241 970420 A1 Diagram 2a Attenuator CH 1 PM3094 PM3092 ...
Page 100: ...5 1 36 UNIT DESCRIPTIONS 12AT3 12AT3 STQ24S 970420 Diagram 3 Attenuator CH 3 PM3094 ...
Page 101: ...J a C3077 I I T b M A AT350C N1101 2AT3 12AT3 ...
Page 102: ...5 1 36 UNIT DESCRIPTIONS 12AT3 STB242 970420 Diagram 3 Attenuator CH 3 PM3094 ...
Page 104: ...5 1 37 12AT4 D4201 3 D4201 5 ST8243 97D420 Diagram 4 Attenuator CH 4 PM3094 ...
Page 105: ...UNIT DESCRIPTIONS C4071 lOn C4072 lOn AC DC f HIGH IMPEDANCE ATTENUATOR LF IMPE CONVE R40Q2 ...
Page 107: ... 12AT 12AT4 l i C4067 160u 25V C4068 10n K4002 ...
Page 109: ...I i 04097 1 0 O u 25V J 25V 10n 25V ...
Page 113: ...UNIT DESCRIPTIONS PROBE CALIBRATOR GNOR6F f 1CVREF f C11S0 180u 25V C1157 10 0n GNDREF GNDREF ...
Page 115: ...5 1 40 UNIT DESCRIPTIONS Diagram 6 Preamplifier CH 1 and CH 2 ...
Page 116: ...PAOREF N32Q2 12 ...
Page 117: ...5 1 40 UNIT DESCRIPTIONS Diagram 6 Preamplifier CH 1 and CH 2 ...
Page 118: ...UNIT DESCRIPTIONS 5 1 41 l GAIN CONTROLVAR X1 2 X5 Diagram 7 Preamplifier CH 3 and CH 4 ...
Page 119: ...UNIT DESCRIPTIONS ...
Page 120: ...5 1 41 PMVAR ft4220 Diagram 7 Preamplifier CH 3 and CH 4 ...
Page 121: ...5 1 42 UNIT DESCRIPTIONS Diagram 8 Y functions ...
Page 122: ... 12FNC12 I2R4C12 12FNC34 12FNC34 R1S13 1K47 FNC FI ...
Page 123: ...5 1 42 UNIT DESCRIPTIONS 12FNC12 FM2MV 00003 7 12FNC12 H2FNC12 Diagram 8 Y functions ...
Page 124: ...UNIT DESCRIPTIONS 10P 120LD REF VOLTAGE DG001 HEF40M I f 1 ...
Page 129: ... REF VOLTAGE j D5001 HEF4009 DS001 HEF40M If C0RHECT10N VOLT N5001 366 f ...
Page 133: ...5 1 45 D5501 HEF4053 CNT STB251 970428 Diagram 10 Display and trigger control ...
Page 138: ...5 1 47 Diagram 12 MTB trigger ...
Page 142: ...5 1 48 UNIT DESCRIPTIONS TV SYNC SEPABATOtT TV UNE FRAME SEUECTKDN Diagram 13 TV line trigger ...
Page 143: ...UNIT DESCRIPTIONS 5 1 49 160TR Diagram 14 DTB trigger ...
Page 146: ...5 1 50 UNIT DESCRIPTIONS Diagram 15 Time base logic ...
Page 148: ...5 1 50 UNIT DESCRIPTIONS V 6 0 0 4 Diagram 15 Time base logic ...
Page 149: ...UNIT DESCRIPTIONS 5 1 51 Diagram 16 Main time base ...
Page 150: ...UNIT DESCRIPTIONS R6001 ...
Page 151: ...5 1 51 ...
Page 153: ......
Page 154: ...5 1 52 UNIT DESCRIPTIONS R716Y C7181 ONLY IN PM30Q2 PM3004 Diagram 17 Delayed time base ...
Page 155: ...UNIT DESCRIPTIONS 5 1 53 X9001 I 1 D 0 O O 8 1 Diagram 18 Connectors ...
Page 214: ...UNIT DESCRIPTIONS 5 2 13 5 2 5 Circuit diagrams A2 200 MHz version ...
Page 215: ...UNIT DESCRIPTIONS 5 2 5 Circuit diagrams A2 200 MHz version 0501 22 ...
Page 216: ...5 2 13 ...
Page 217: ...5 2 14 UNIT DESCRIPTIONS A2 200 MHz Diagram 2 Final Y output stage ...
Page 218: ......
Page 219: ...5 2 14 UNIT DESCRIPTIONS STB263 970428 A2 200 MHz Diagram 2 Final Y output stage ...
Page 223: ...5 2 16 UNIT DESCRIPTIONS AC20mV DC 10V AC 80mV OCMOV A2 200 MHz Diagram 4 Final Z amplifier ...
Page 224: ...AC 60mV DC 1CV R3311 511E M20Q2 11 AST03 R3313 1 2KB7 V3311 ...
Page 226: ...UNIT DESCRIPTIONS 5 2 17 A2 200 MHz Diagram 5 Modulator demodulator and focus control ...
Page 227: ...UNIT DESCRIPTIONS FOCUS L i X2401 ...
Page 228: ...5 2 17 A2 200 MHz Diagram 5 Modulator demodulator and focus control ...
Page 231: ...8 5 ii 8 HI I Hl H s HI I i HI I ...
Page 232: ...g I S 5 S I 1 H H r lr H J g if j r r 8 3 8 8 S 3 5 5 H H 5 3 r l r l H H n ft 3 S 5 8 a s 5 ...
Page 268: ...UNIT DESCRIPTIONS 5 2 11 Circuit diagrams A2 100 MHz version ...
Page 269: ...5 2 47 ...
Page 270: ...5 2 48 UNIT DESCRIPTIONS TO CflT ...
Page 271: ......
Page 280: ...UNIT DESCRIPTIONS X2411 ...
Page 281: ...5 2 51 FOCUS LEVELSHIFTER A2 100 MHz Diagram 5a Modulator demodulator and focus control ...
Page 284: ... ...
Page 285: ...a 5 a I H rI 3 H H H 8 K fc 5 3 3 I I ...
Page 308: ...t 0 0 0 0 0 0 0 0 0 3 sS cn 03 03 UNIT DESCRIPTIONS ...
Page 310: ...R1102 R1101 R1679 R1672 R1071 R1104 B1674 u HI 406 H i402 D1402 O N j oo O O ai 5 3 ...
Page 311: ...bc646c Up BC866C 3Lp ...
Page 313: ......
Page 317: ...UNIT DESCRIPTIONS 5 3 9 5 3 5 Circuit diagrams Diagram 1 Central processor unit ...
Page 318: ...UNIT DESCRIPTIONS 5 3 5 Circuit diagrams ...
Page 319: ...5 3 9 r i Diagram 1 Central processor unit ...
Page 324: ...UNIT DESCRIPTIONS ...
Page 325: ...5 3 11 Cl 968 T 1 0 0 n C1963 I80u Diagram 3 Potentiometer DAC and lEEE option h i m ...
Page 326: ...5 3 12 UNIT DESCRIPTIONS G4 oi TEXT CURSOR CONTBOL 12MG Diagram 4 Text and cursor circuit i ...
Page 328: ...5 3 12 UNIT DESCRIPTIONS G4401 12MG TEXT CURSOR CONTROL Diagram 4 Text and cursor circuit ...
Page 342: ...UNIT DESCRIPTIONS 5 4 4 Unit lay outs TO X5201 ON CRT CONTROL A5 I O C O I D C G C I ...
Page 344: ...UNIT DESCRIPTIONS 5 4 4 Unit lay outs TO X5201 ON CRT CONTROL A5 H cc c c IH ...
Page 360: ...sna iu o UNIT DESCRIPTIONS 5 5 3 5 5 3 Circiuit diagram X5201 A5 Diagraml CRT controls unit ...
Page 367: ...UNIT DESCRIPTIONS 5 6 3 Unit lay outs TO X2401 ON ...
Page 369: ......
Page 371: ......
Page 372: ... 00 o o O o ...
Page 377: ...UNIT DESCRIPTIONS 5 6 5 Circuit diagrams G LI 001 fKfcjH ...
Page 379: ...5 6 10 t ...
Page 381: ... EHT CONVERT ...
Page 383: ...UNIT DESCRIPTIONS OUTPUTCIRCUIT V1271 BYV29 T1001 T1001 T1001 now T1001 T1001 now now ...
Page 394: ...UNIT DESCRIPTIONS 5 7 1 5 7 RESERVED FOR FUTURE EXTENSIONS ...
Page 395: ...UNIT DESCRIPTIONS 5 8 1 5 8 RESERVED FOR FUTURE EXTENSIONS ...
Page 396: ...UNIT DESCRIPTIONS 5 9 1 5 9 RESERVED FOR FUTURE EXTENSIONS ...
Page 397: ...UNIT DESCRIPTIONS 5 10 CONNECTOR BOARD A10 5 10 1 Unit lay out ...
Page 399: ...UNIT DESCRIPTIONS 5 10 CONNECTOR BOARD A10 5 10 1 Unit lay out 28 27 O O X IAJ 2 1 ...
Page 412: ...UNIT DESCRIPTIONS 5 11 3 Fig 1 Location of options Y out and external trigger ...
Page 413: ...UNIT DESCRIPTIONS ...
Page 414: ...5 11 3 Fig 1 Location of options Y out and external trigger ...
Page 415: ...5 11 4 UNIT DESCRIPTIONS Fig 2 Printed circuit board lay out of Y out unit ...
Page 417: ...UNIT DESCRIPTIONS 12V 12V 12V 12V X1003 YOP HX R1001 I 1 2 K 1 X1009 X1010 SCL ...