JPH0376202U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram representatively showing the internal configuration of a rotary head with a built-in preamplifier according to an embodiment of the present invention, including one system of video heads and related circuits, and Fig. 2 shows a conventional built-in preamplifier. FIG. 3 is a circuit diagram showing a configuration that can be easily considered when a preamplifier is built into the rotary head of FIG. 2. Ha...Video head for both recording and playback, Ca
... Rotating side coil of rotary transformer, S1,
S2...Signal line pair, PA...Preamplifier, SW1
~SW4...Switch for switching between recording operation and playback operation.

Claims (1)

[Claims for Utility Model Registration] A video head used for both recording and playback operations, a rotating coil of a rotary transformer, and a pair of signal lines connecting the terminals of the video head and the rotating coil of the rotary transformer. , a playback-only preamplifier inserted into one side of this pair of signal lines with its output terminal facing the rotary transformer, and a second preamplifier inserted into the other pair of signal lines, which is opened during playback and closed during recording. 1 switch, second and third switches connected between the input/output terminal of the preamplifier and the reference voltage, opened during playback operation and closed during recording operation, and each terminal of the first switch. A rotary head with a built-in preamplifier, characterized in that a fourth and fifth switch is built in, which are connected between the preamplifier and the reference voltage, and which are closed during playback operation and opened during recording operation.