| 摘要 |
PURPOSE: An apparatus for preventing dazzling is provided to stably protect the worker's eyes by changing light transmittance based on light and electromagnetic wave detected from a welding or cutting torch. CONSTITUTION: An apparatus comprises an RF signal detector (16) for detecting electromagnetic wave which is generated from a welding or cutting torch. The RF signal detector (16) is a circuit for receiving a specific frequency band from the electromagnetic wave which is introduced through an antenna (6). The RF signal detector (16) comprises a resonator part (32), a filter part (34), a comparing part (36), and a smoothing part (38). The resonator part (32) is switched by a frequency which is applied to a base through a coil (L1) of the antenna (6), and includes NPN transistor (Q1) in which power (Vcc) is applied through a resistor (R1) to a collector. The filter part (34) for removing the noise from the output of the resonator part (32) is comprised of condensers (C1, C2, C4), a resistor (R2), resistors (R3, R4), and a condenser (C3). The comparing part (36) for comparing the output of the filter part (34) with a predetermined value has a comparator (37). The smoothing part(38) is used for smoothing the output of the comparing part (36).
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