Stereophonic signal phase detector - has two amplifier and integrating channels which provide power to LED display for in-phase and in-opposition conditions

摘要

The phase detection method is esp. for stereophonic signals. The detector provides an output indicating in phase or in opposition conditions for complex signals, i.e. signals having a wide range of frequency and amplitude components. The two input channels (C1, C2) are coupled into the circuit by a pair of transformers each having twin secondaries (21, 22, 31, 32) one transformer only having a connection sense reversal switch (1). The secondaries feed two operational amplifiers and integration chains (4-7). One amplifier acts as an addition circuit and the second a subtraction, their outputs being integrated in an RC circuit which includes a detection diode (61, 71). Teh interated outputs are compared in a further resistive feedback operational amplifier (80) with a back to back diode (86) pair input circuit. The comparator output directly feeds an LED pair (90, 91) indicating IN or OPPOSITION phase conditions.