PURPOSE: To stabilize the operation of a proximity switch, by inputting the output of the integration circuit of the proximity switch into a comparator containing transistors having split collectors and comparing the output with a reference voltage.
CONSTITUTION: The output of an oscillating circuit which detects the approach of metals, etc., through the change in output amplitude is inputted into one terminal IN of an integration circuit. The input voltage of the terminal IN is compared with the reference voltage of a comparator composed of transistors (TR) 21 and 22. When the base input voltage of the TR21 is smaller than the reference voltage VS2 of the TR22, the TR21 is turned off and TR22 is turned on and, as a result, a TR23 having a split collector is turned off and another TR24 having a split collector is turned on and an electric current is made to flow to a load 28. The TRs 23 and 24 constitute a current mirror and the TR23 supplies an electric current which (n) times larger than the electric current flowing to the collector of the TR21 from the TR23 to the collector of the TR22 and the TR24 supplies an electric current which is (m) times larger than the electric current supplied to the TR22 to the TR21. The TRs 23 and 24 form a feedback circuit against the comparator and can make stable operation.
KUNO SHINICHI
NISHIMOTO IKUO
KAWASHIMA GIICHI
| JPS5539110A | 1980-03-18 | |||
| JPS4741456A | ||||
| JPS5515125A | 1980-02-02 |