Analog signal detection circuit, and the ac current detector provide for a half conductor power transfer device

摘要

Usually, there is a problem in the fact that it is not possible, an analog signal detection circuit with a high level of reliability and long service life under unfavorable operating conditions, since a photocoupler for an electrical insulation of a digital signal is used. In contrast, an analog signal detection circuit (1a, 1b), respectively, is provided with a carrier waves generate a unit (32) for generating a carrier wave, a pulse width modulation of a unit (31) for a pulse width modulation of a of the signal input connection by using the input analog signal by the carrier waves generate a carrier wave generated unit (32) and for outputting a digital signal, an hvic - unit with rearwardly level displacement (30) for transmitting the digital signal from a power supply system to another power supply system and a demodulator unit (33) for demodulating the to the other power supply system which is transmitted digital signal into an analog signal and outputting of the same in the case of a signal output connection (3). Dollars a as a result it is possible in an analog signal itself, in the case of detecting, in which the reference potentials differ from one another in the case of signal input / output terminals.