JPS6034172B2 - Tape recorder timer start circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a timer start circuit in a tape recorder, and an object of the present invention is to select whether to start recording or playback when the timer starts, depending on the operating state of a single switch. An embodiment of the present invention, which provides a timer start circuit, will be described below with reference to the drawings.

In the figure, 1 is an R/S type FF circuit for switching green tone.
When the output of the NAND circuit 2 rises to H level, it is set and output Q is set to H level, and when the output of /A circuit 3 rises to H level, it is reset and output Q is set to L level. and,
NAND circuit 2 has playback (PLAY) switch 4 and recording (R
EC) Outputs the time and date level when switch 5 is pressed, and the NOR circuit 3 outputs fast forward (FF) switch 6 and rewind (
When either the REW switch 7 or the STOP switch 8 is pressed, the time and date level output is output. Reference numeral 9 denotes a decoder, which outputs an H level output to terminal 9a after a certain period of time by applying a certain voltage to terminal 1B, and makes transistor Q conductive for a certain period of time via capacitor C. An L level signal is applied to both inputs of the NAND circuit 2 via the set switch 10 and diodes D and D2.

Terminals 9b to 9e of the decoder 9 are drive signal input terminals, which are connected to the output sides of the stop switch 8, rewind switch 7, fast forward switch 6, and playback switch 4, respectively, and the decoder 9 responds to the operation of these switches. A signal is sent to the control circuit 11 that controls the mechanical section and the circuit section. This control circuit 1
By receiving an H level signal from the output Q of the FF circuit 1, the bias signal from the recording bias circuit 12 is added to the recording signal and sent to the recording head 13, and the erasing head 14 is excited.

Note that the recording bias circuit is activated when the output Q of the FF circuit 1 becomes H level. 15 is a playback head, 1
6 is a magnetic tape.

Further, reference numerals 18 and 19 are movable safety switches which short-circuit the recording head 13 and erasing head 14 when closed. 17 is a power off circuit that supplies voltage to the 10B terminal of the decoder 9;
The voltage at the point is the power switch 20 and the timer operation switch 21.
The voltage of the power supply circuit 22, which is operated by the operation of , rises to 10 V in a time determined by the resistor R and the capacitor C2.

Transistor Q2 is conductive while a voltage of 10 V is applied, making transistor Q conductive and transistor Q4 cut off, and charging capacitor C3. This capacitor C3 acts as a bias for transistor Q2. In the above, if the power switch 20 is closed and a timer (not shown) is set, the timer set switch 10 is opened, and the safety switches 18 and 19 are opened, then the timer is activated. When switch 21 is closed, a voltage +V appears across the circuit. As a result, the FF circuit 1 is directed to the reset state. and,
When the voltage at point A reaches a predetermined value after a certain period of time, an H level signal is output from terminal 9a of decoder 9 after a certain period of time, and transistor Q becomes conductive due to the differential current flowing through capacitor C for a specified period of time. As a result, both inputs of the NAND gate 2 are grounded through the diodes D, , D2 for a certain period of time and become L level, so that the output of the NAND gate 2 becomes H level and the FF circuit 1 is set. As a result, the output Q of the FF circuit 1 becomes H level, and the recording bias circuit 12 is activated.
The recording head 13 and erasing head 14 are controlled by the control circuit 11.
begins to demonstrate its capabilities. As described above, when the timer works, the recording operation starts after the time until the voltage at point A rises and the time until the H level signal rises at terminal 9a of decoder 9. .

In other words, it becomes possible to record while the user is away. Note that even if the timer is set and the timer set switch 10 is closed, if the safety switches 18 and 19 are left open, the recording head 13
Since the erase head 14 does not work, only the reproducing operation is performed. Further, due to the action of the capacitor C, the transistor Q, conducts only when the power is turned on based on the timer operation, and then shuts off. Therefore, the locking type timer set switch 10 does not affect the circuit after that, and therefore, Even if the timer set switch 10 is open, the operation can be performed based on normal manual operation.

When the power switch (not shown) is opened, normally the position of point A gradually decreases due to the action of capacitor C2, but in this embodiment, transistor Q2 immediately shuts off due to a slight decrease in voltage of 10 V. This turns off transistor Q3, so the charge on capacitor C3 makes transistor Q4 conductive, which causes capacitor C2
Therefore, the potential at point A drops to the ground potential almost at the same time as the power switch 20 is opened.

Therefore, an unstable voltage is not applied to the terminal +B of the decoder 9, and malfunctions are prevented.
That is, when the voltage of 10 V gradually decreases, the decoder 9
In other words, since the central part immediately stops its operation, no command is input based on the malfunction of other circuits, thus preventing malfunction. As described above, according to the present invention, the playback operation is performed by the output of the decoder which receives the pulses generated by the playback operation at the playback drive signal input terminal, and the output of the FF circuit set by the pulses generated by the playback and recording operations performs recording. In the tape recorder that operates, the decoder is provided with a delay function, and a different signal is output after a certain period of time after the power is turned on, and a signal obtained by differentiating the signal is sent to the set terminal of the FF circuit and the decoder via a timer set switch. The playback drive signal is applied to the input terminal, and the recording operation is made possible by operating a safety switch.

Therefore, if you operate the timer set switch and set the safety switch to recording, you will be able to record while you are away when the power is turned on due to the timer activation, and if you set the safety switch to non-recording at this time, you will be able to playback. As the movement is performed, one becomes aware of it and can perform regeneration.

Furthermore, once the entire system is in operation, opening and closing the timer set switch does not affect the circuit at all, so less attention is required during normal operation.

[Brief explanation of the drawing]

The figure is a circuit diagram showing one embodiment of the present invention. 1...FF circuit, 9...decoder, 1
0...Timer set switch, 11...
・Control circuit, 12... Recording bias circuit, 13
... Recording head, 14 ... Erasing head, 15 ... Playback head, 16 ... Magnetic tape, 17 ... Power supply circuit, 18 ,19...
... Safety switch, 20 ... Power switch,
21...Timer operation switch.

Claims (1)

[Claims] 1. Equipped with a decoder that receives pulses generated by a playback operation at a playback drive signal input terminal, and an FF circuit that is set by the pulses generated by simultaneous playback and recording operations,
When a pulse is received at the playback drive signal input terminal, the output of the decoder forms the playback operation state, and the set FF
In a tape recorder in which an operating state of a recording circuit is formed by the output of a circuit, and a recording operating state is formed by simultaneously forming a playback operating state and an operating state of the recording circuit by simultaneous playback and recording operations, the decoder has a delay. A different signal is output after a certain period of time after the power is turned on, and a signal obtained by differentiating the signal is applied to the set terminal of the FF circuit and the reproduction drive signal input terminal of the decoder via a timer set switch. , set FF
A timer start circuit for a tape recorder, comprising a switch that selectively disables the formation of the operating state of a recording circuit by the output of the circuit.