Voltage measuring device for an encapsulated high-voltage switching installation

A voltage measuring device for use with an encapsulated, high-voltage switching installation including an inner conductor within a grounded metallic outer tube, which comprises:

• a. means for widening said outer tube to thereby form a space for locating certain portions of said measuring device;
• b. auxiliary electrode means positioned in said space, said auxiliary electrode means and said inner conductor forming a first capacitor;
• and,
• c. means operatively connected to said first capacitor and adapted to respond to electrical characteristics of said first capacitor to thereby give an indication of the voltage of said installation, said operatively connected means including:
• a second capacitor connected between said auxiliary electrode means and said metallic outer tube, said first and second capacitor forming a voltage divider between said inner conductor and said grounded metallic tube, said second capacitor having a capacitance value such that the voltage across said second capacitor is lower than that across said first capacitor;
• and, indicating means connected to said second capacitor and adapted to respond to the voltage developed across said second capacitor.

A voltage measuring device for use with an encapsulated, high-voltage switching installation including an inner conductor within a grounded metallic outer tube, which comprises:

• a. means for widening said outer tube to thereby form a space for locating certain portions of said measuring device;
• b. auxiliary electrode means positioned in said space, said auxiliary electrode means and said inner conductor forming a capacitor, said auxiliary electrode means including:
• an electrode having an opening;
• and, a metal disc pivotally mounted to said electrode and positioned such that said disc rotates in response to the electric field forces exerted between said inner conductor and said disc;
• and,
• c. means for measuring the rotational movement of said disc to thereby give an indication of the voltage between said inner conductor and said outer tube, said means for measuring the rotational movement includes:
• a mirror secured to said disc;
• a source of light directed at said mirror;
• and calibrated scale means onto which light reflected from said mirror is displayed.