CURRENT/VOLTAGE DETECTION CIRCUIT EMPLOYING LIGHT EMITTING ELEMENT

摘要

PURPOSE:To facilitate the measurement of the direction of current or polarlity of voltage at a close distance to an object to be measured by incorporating a variable color light emitting element adapted to vary in the color tone depending on the direction of current into a measuring probe. CONSTITUTION:An anti-parallel circuit of diodes 13 and 14 is connected to the secondary coil E2 side of a power transformer 11 through a resistance 12 and light emitting elements 15 and 16 are connected in series to the diodes respectively in such a manner as to match in the polarity. Then, an object 27 to be measured is inserted between terminals A1 and A2. Either the light emitting element 15 or 16 emits light depending on the direction of current or the polarity of the object 27 being measured. When the object 27 is short-circuited, both the light emitting elements 15 and 16 emit light in the intermediate color tone. When formed on a part of lower circumference of a measuring prove 30, a display 31 having a head of this variable color light emitting element enables the measurement of the direction of current or the polarity of voltage without shifting view to the body of a measuring apparatus 28.