ISOXAZOLE- AND ISOTHIAZOLE-5-CARBOXYLIC ACID AMIDES AND HERBICIDES CONTAINING SAID COMPOUNDS

摘要

PURPOSE:To stabilize and control a plate voltage without using a resistance for high voltage by controlling the plate voltage of a vacuum tube type light emitting tube by detecting the current flowing through an auxiliary plate. CONSTITUTION:A DC-DC converter 2 for supplying a plate power is connected to a plate P of a tetrode vacuum tube type light emitting tube 1. An output terminal of a current detection circuit 4 for detecting the current flowing through the backplate BP of the light emitting tube 1 is connected to the voltage regulator terminal of the converter 2. The converter is adjusted in advance to output a specified voltage and its voltage adjusting terminal is controlled by the output signal of the current detection circuit 4 to control the output voltage of the DC-DC converter 2.