| 摘要 |
In a device for automatic testing of power capacitors with high capacitance the tested power capacitor (1) is complemented to the parallel oscillating circuit with the inductor (3) with low losses. The inductor (3) inductance value is selected such that at the testing frequency it has the same reactance as the tested power capacitor (1). To the series combination with the tested power capacitor (1) connected in parallel with the inductor (3) is inserted the first current sensor (2.1) by its input terminals. Its output is connected both to the input of the regulating amplifier (9) and to one input of the phase detector (10). To one of the connections between the parallel oscillating circuit and the output of the power amplifier (6) is connected the second current sensor (4.1) by its input terminals, the output of which is connected to the second input of the phase detector (10). The output of the phase detector (10) is via the integrating amplifier (11) and the voltage-controlled oscillator (8) connected to one input of the adjustable attenuating element (7), while to its second input is connected the output of the regulating amplifier (9). The output of the adjustable attenuating element (7) is connected via the power amplifier (6) to the common connection of the inductor (3) and the first current sensor (2.1) and to the second input of the second current sensor (4.1). For testing of power capacitors with lower capacitance the connection is similar where the tested power capacitor (1) is complemented with the inductor (3) to series oscillating circuit. The inductor (3) is bridged by the first voltage sensor (2.2) connected to the input of the regulating amplifier (9) and to one input of the phase detector (10). In parallel with the series oscillating circuit is connected the second voltage sensor (4.2), the output of which is connected to the second input of the phase detector (10). |
