| 摘要 |
Input circuit for an electronic oscilloscope, containing anti-parasitic resistors, a dual-position input coupling switch, a coupling capacitor, one RC-type voltage divider with high frequency compensation, capacitors of variable capacity determining the input capacity, multi-sectional mechanically coupled sweep coefficient switches, a resistor/diode-based safety circuit and a high-impedance source input follower and the output terminal of that RC-type frequency-compensated voltage divider connected to a set of terminals of the mechanically coupled sweep coefficient switch, which in turn are connected via the slider of that switch to the input terminal of the resistor/diode-based safety circuit, characterized in that the input terminal (5) of the only frequency-compensated input divider (6) is permanently connected to the slider of the dual-position input coupling switch (3) and to one variable-capacity capacitor (7) determining the input capacity, whose second end is connected to the terminals (8), shorted with each other, of the second set of the second section of the sweep coefficient switch (9), and in addition to the input terminal (5) of the only compensated input divider is connected to the first set of terminals (11) of the first section of the sweep coefficient switch (9), whose slider is permanently connected to the input terminal (12) of the resistor/diode-based safety circuit (13), and the mechanical coupling (10) of the first and second sections of the sweep coefficient switch (9) ensures that, when the slider of the first section of the sweep coefficient switch (9) connects the terminals (11) of the first set of that first section, the slider of the second section of the sweep coefficient switch (9) connects the corresponding terminals (22) of the first set of this second section which are free, and when the slider of the first section of the sweep coefficient switch (9) connects the terminals (17) of the second set of that first section, which are connected to the output terminal (16) of the RC-type frequency compensated divider (6), the slider of the second section of the sweep coefficient switch (9) earths the corresponding terminals (8) of the second set of that second section.
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