Inductance-capacitance detection oscillator for inductive proximity detector, has excitation stage comprising PNP transistor that is connected to NPN-type transistor so as to form Sziklai pair with NPN-type transistor

摘要

The oscillator has a resonant circuit comprising two inductors (L1, L2) wound together on a magnetic circuit. An excitation stage is connected to the resonant circuit and provided with a PNP-type transistor (Q1) and a NPN-type transistor (Q2), where the NPN and PNP type transistors are connected with each other. The excitation stage comprises another PNP-type transistor (Q3) that is connected to the NPN-type transistor so as to form a Sziklai pair with the NPN-type transistor. The PNP-type transistor is connected to a common collector.