Kikusui TOS9200, Руководство по эксплуатации

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TOS9200/9201 Appendix A-3
during the test. The voltmeter constantly monitors the voltage on the output termi-
nal, even when no test is under way. When a voltage is detected, the voltmeter turns
on the DANGER lamp.
(b) Analog voltmeter
Recti fi es currents fl owing into divider resistors, and drives the DC voltmeter. Con-
ducts voltage measurement in AC/DC withstanding voltage testing, as well as insu-
lation resistance testing.
[10] Current detection circuit
(a) Current detection circuit for withstanding voltage testing
Converts the current fl owing into the output terminal into a voltage using the refer-
ence resistance, and further transforms it into a DC voltage in the AC/DC conver-
sion circuit. This voltage is input to the A/D converter and displayed on the LCD.
Compared with Kikusui’s conventional counterparts, which have a measurement
resolution of 1 mA and accuracy of ±5% of the upper current when the upper cur-
rent is set to 100 mA, this tester enables measurement with an accuracy of ±(3 % of
r 20 μ A) to be conducted even at an upper current of 100 mA.
(b) Current detection circuit for insulation resistance testing
Converts the current fl owing into the output terminal into a voltage in the current-
voltage conversion circuit, and collects it in the A/D converter. The insulation resis-
tance value is determined by dividing the voltage measured on the voltmeter for
insulation resistance testing by the current obtained in this current detection circuit.
The insulation resistance value is then displayed on the LCD.
[11] Judgement circuit
In withstanding voltage testing, this circuit compares the DC current measured in
the current detection circuit with the reference voltage, which corresponds to the
preset upper or lower current. If a current exceeding the upper current is detected,
the circuit determines that a withstanding voltage error has occurred and cuts off the
test voltage. In addition, if detected currents are below the lower current, the circuit
determines that the high-voltage test leadwire is disconnected or in poor contact,
and thus cuts off the test voltage.
[12] Control circuit
Controls the test voltage. This circuit also manages voltage measurement, current
measurement, judgement, and test time, in addition to conducting sequence control
on the CPU.
[13] POWER SUPPLY
Converts AC voltages from an AC line into DC voltages in order to supply them to
circuits