Temperature pickup for oil-filled vessels and temperature measurement method

US6224255A · kind A · utility

Assignee

• MASCHINENFABRIK REINHAUSEN GMBH · DE

Inventors

• Manfred Stadelmayer · Wenzenbach, DE
• Karsten Viereck · Teisendorf, DE

Key dates

• Filing date: May 11, 1999
• Grant date: May 1, 2001
• Expiry date: May 11, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03K9/08
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A temperature pickup for an oil-filled transformer or tap changer has within a resistance thermometer standard housing, the circuitry for duty-factor-modulated output of a measurement signal, interference circuitry which can slur the resulting wave form and an interface circuit which subjects the output signal to polarity reversal to produce an output symmetrical with respect to ground potential. This enables zero crossings to be detected and the time lapse between zero crossings or passages to be ascertained and the temperature calculated from the duty-factor ratio.