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HOUILLERE DE LIEVIN SOC
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HOUILLERE DE LIEVIN SOC
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Publication of FR431921ApublicationCriticalpatent/FR431921A/fr
H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/738—Interface circuits for coupling substations to external telephone lines
H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults
H04M1/745—Protection devices or circuits for voltages surges on the line
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Engineering & Computer Science
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Signal Processing
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FR431921D1911-06-191911-06-19Téléphone de sécurité pour locaux à danger d'explosion
ExpiredFR431921A
(fr)