TWO-WIRE TYPE CONTACTLESS SWITCH

• Main Author: TANIGAWA KIYOSHI
• Format: Patent
• Language: English
• Published: 30.04.1992
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

PURPOSE:To decrease a voltage drop when two terminals are closed by selecting a serial controlled constant voltage circuit or a parallel controlled constant voltage circuit based on an output of a detection circuit and turning on or short-circuiting a series control element for a period when the parallel controlled constant voltage circuit is acted. CONSTITUTION:Analog switches 28, 29 and an inverter 30 are used and an output of a detection circuit 9 is used to select an output switching circuit 5 to a constant voltage circuit 6. When the detection circuit 9 detects no sensing body, a series controlled constant voltage circuit 6 is active, a voltage of an internal circuit is kept constant, and when the detection circuit 9 detects a sensing body, the output of the circuit 9 is used to select a series control element 19 of the series controlled constant voltage circuit 6 to be turned on through a low resistance or short-circuited and the output switching circuit 5 acts like the parallel controlled constant voltage circuit together with part of the series controlled constant voltage circuit 6. Thus, the voltage drop when the two terminals 3, 4 are closed is lowered.