JPS5942377B2 - Timer automatic cutoff method for magnetic recording and reproducing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording/reproducing device, particularly to an automatic timer shutoff system for a video tape recorder.

As is well known, in a video tape recorder, a timer is used to perform recording while the user is away, but conventionally, recording is simply started at a desired timing and ended after a certain period of time. Therefore, even if you try to continue recording as long as the tape lasts, there is a risk that recording will be canceled midway through, which is a particular problem when trying to record on multiple cassette tapes in timer mode. In view of this, the present invention is characterized in that the hold circuit that holds the output timing signal of the timer is configured to be reset after a predetermined time delay at the end of recording.

The present invention will be described below with reference to the embodiments shown in the drawings. In the drawings, 1 is a timer, 2 is a hold circuit, 3 is a relay drive circuit, 4 is a switch linked to the record button of the video tape recorder 9, 5 is a time constant circuit, 6 is a Schmidts circuit, T is a relay, 8 is an AC power supply, 10 is a relay drive coil, and 11 is a diode.

Now, when the timer 1 is set and a predetermined time elapses, a timing signal is generated, which is held in the hold circuit 2, so that the relay drive circuit 3 is turned on and the coil 10 is energized.

Therefore, the relay T is turned on, and the video tape recorder 9 is energized from the power supply 8. At this time, since the switch 3 is turned on in conjunction with the record button, +B power is applied to the base of the transistor Tr of the time constant circuit 5, turning it on. As a result, the transistor T
The collector of r is at ground potential, capacitor C is not charged, and Schmitt circuit 6 is not activated. Next, the video
In the tape recorder 9, when recording is completed, the record button is released and the switch 4 is turned off, so that the transistor Tr is also turned off.

Therefore, the capacitor C of the time constant circuit 5 is charged, and when it reaches a predetermined potential after a time determined by the time constant RC, the Schmitt circuit 6 is activated and the hold circuit 2 is reset by its output signal, so that the relay drive circuit 3 is turned off, the relay coil 10 is deenergized, and the relay T is turned off. In this way, if the delay time determined by the time constant of the time constant circuit 5 is set appropriately, for example, when recording on multiple cassette tapes, even if the record button is temporarily turned off when changing cassettes, if the delay time is longer than this off time, the recording will continue. Can be recorded.

Note that the delay means is not limited to a time constant circuit.

[Brief explanation of the drawing]

The figure is a route map showing one embodiment of the present invention. 1: Timer 1, 2: Hold circuit, 4: Record button interlocking switch, 5: Time constant circuit, 6: Schmitt circuit, 7:
Relay for applying power, 8: AC power supply, 9: Video tape recorder.

Claims (1)

[Claims] 1. A timer, a magnetic recording and reproducing device, a switch for applying power to the magnetic recording and reproducing device, a hold circuit that holds a timing signal from the timer, and means for turning on the switch by the output of the hold circuit. and means for resetting the hold circuit with a predetermined time delay upon completion of recording in the magnetic recording/reproducing device.