H.F. generator circuit for medical short wave therapy appts. - has quartz oscillator, level regulator and two power amplifiers for level control via OR gate

摘要

The h.f. generator includes a ladder network of circuits comprising a quartz oscillator (3), a controllable level regulator (4), a driving stage (5), an output stage (6) and a transformation network (7). The latter is followed by two T-networks (1,2 and a power and mismatch detector (LFM). The latter supplies the voltage sum (v), the difference voltage (r) and the collector a.c. voltage of the output stage. The voltage sum (V) and difference voltage (R) are fed to an analogue processing unit (11). The rectified h.f. collector voltage controls a phase regulator (10). Two amplifiers (V1,V2) in the analogue processing unit working in the power loop control the operating level via an OR gate (8). ADVANTAGE - Efficient, high spectral purity, good control characteristics.