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Patent Searching and Data

Document Type and Number:
Japanese Patent JP3141968
Kind Code:

PURPOSE: To detect a high voltage with high accuracy by a method wherein one terminal of a voltage-holding circuit is connected to a ground terminal of a voltage detection circuit and a terminal voltage is maintained at a constant level.
CONSTITUTION: A voltage-holding circuit 2 consists of a zener diode 21 and a resistor 22 and the value of the resistor 22 is so selected that the current flowing in the diode 21 permits the zener diode to have the most stable zener voltage when a current to be detected is applied to an input terminal 11a. Assuming that a zener voltage is Vz and detected voltage of a voltage detector 1 is Vd, a voltage of the ground terminal 16 of the detector 1 held by the circuit 2 is Vz. When an input voltage is higher than Vd+Vz, an output transistor 14 turns off and when the voltage is lower than that, it turns on. The detection error of the circuit is equal to the sum of an error of the detector 1 and the voltage Vz so that when selecting the diode having the stable voltage, the highly accurate detection of a voltage can be performed.

Sawamura, Hiroshi
Application Number:
Publication Date:
March 07, 2001
Filing Date:
March 08, 1993
Export Citation:
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International Classes:
G01R19/00; H03K5/08; (IPC1-7): G01R19/00; H03K5/08
Attorney, Agent or Firm:
宮園 純一