Phase control for magnetic tape recorder - comprises tape head with reference vertical sync. signals and on correct phase relation switches to compare horizontal sync. signals

摘要

The phase control, for a magnetic tape recorder, derives a control signal for the head drum's drive circuit (3) by comparing the vertical sync. signal (2Vr) from a reference source with the output signal of the tachogenerator (4) coupled to the drum drive. When these two input signals bear a given phase relationship to one another, a signal is sent to an electronic switch (2) between the comparator output and the drive circuit. The switch connects the output of a second phase comparator (7) to the drive circuit. The second comparator compares the horizontal sync. signal (Hr) from a reference source with the horizontal sync. pulses (Hb) obtained from the tape.