1730–Series Theory of Operation
4–28
High Voltage Power Supply
Diagram 9
The High Voltage Power Supply generates the heater, cathode, control grid, focus
anode, and post accelerating potentials required to display the outputs of the
Vertical and Horizontal Output Amplifiers.
The High Voltage Power Supply is generated by a sine-wave oscillator and
step-up transformer. Q6 and T1 are the principal elements of an Armstrong
oscillator running at about 22 kHz. Error Amplifier U2 regulates the +100 V
output and keeps the High Voltage Power Supply constant under varying load
conditions by controlling the base current to Q6. The +100 V output is regulated
directly, while the High Voltage Power Supply is indirectly regulated through a
current feedback circuit.
R48, C16, R60, and R64 form the High Voltage Power Supply current feedback
circuit. As the current from the High Voltage Power Supply is increased, the
voltage to the + side of the Error Amplifier (U2) increases, which increases the
base drive to Q6, the HV Osc. This current feedback compromises the regula-
tion of the +100 V supply to keep the high voltage constant with varying
intensities.
C66 and Q10 are a start delay circuit that holds the Error Amplifier output low,
through CR30, until C66 is charged. Delaying the start of the high voltage
oscillator allows the Low Voltage Power Supply to start, unencumbered by the
load from the high voltage oscillator.
CR4 is the high voltage rectifier. Filter capacitors C3, C4, and C8 work with
CR4 to provide –2530 V to the CRT cathode. U1 is a four-times multiplier
pro11 kV to the CRT anode.
HV Osc and Error Amp
Power Supply Outputs
Summary of Contents for 1730 Series
Page 4: ......
Page 12: ...Contents viii...
Page 17: ...Introduction and Specifications...
Page 18: ......
Page 32: ...1730 Series Introduction 1 14...
Page 33: ...Operating Instructions...
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Page 62: ...1730 Series Operating Instructions 2 28...
Page 64: ...Service Safety Summary S 2 1730 Series B070000 Above...
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Page 67: ...Installation...
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Page 82: ...1730 Series Installation 3 14...
Page 83: ...Theory of Operation...
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Page 115: ...Checks and Adjustments...
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Page 159: ...Maintenance...
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Page 180: ...1730 Series Maintenance 6 20 3 Remove the board by slipping it through the front panel opening...
Page 184: ...1730 Series Maintenance 6 24 Figure 6 8 Repackaging a 1730 Series instrument...
Page 185: ...Options...
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Page 189: ...Replaceable Electrical Parts...
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Page 222: ...1730 Series Replaceable Electrical Parts 8 32...
Page 223: ...Diagrams Circuit Board Illustrations...
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Page 247: ...Replaceable Mechanical Parts...
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Page 255: ...1730 Series Waveform Monitor FIG 1 EXPLODED VIEW A1 A3 A2 A3A1 A10 A11...
Page 256: ...1730 Series B070000 Up...
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