JPS6214131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a preset circuit for an electronic digital counter.

Conventionally, preset circuits for electronic counters have two functions: an addition switch that counts up to change the displayed count value to the desired count value, and a subtraction switch that counts down to the desired value when the desired value is exceeded. I needed two switches. For example, there are digital clocks, digital tuning radio receivers, tape recorder tape counters, etc. that use electronic counters, but digital clocks can be used to adjust the clock, set alarm times, and receive digital tuning radio receivers. The above two switches were required to preset the frequency of the machine, and also to preset the electronic tape counter of the tape recorder.

The present invention combines the functions of the two preset switches described above into one switch, and one embodiment thereof will be described below with reference to the drawings.

In Fig. 1, 1 is a non-lock type, normally open preset switch, and the timer shown in Fig. 2 a is
When switch 1 is _turned on at t ₀ , A
The voltage at the point becomes 0, and in the differential pulse generation circuit 3,
The voltage change is differentiated to obtain the differentiated pulse shown in FIG. 2b. This differential pulse acts as a trigger for the next-stage timer means, specifically a monstable multivibrator (hereinafter abbreviated as monomulti) 4, and also acts as a trigger for a so-called up-down counter 7, which is a reversible electronic counter with addition and subtraction functions. Input to the terminal side. This input pulse causes the counter 7 to perform a subtraction operation by one count.

Further, the voltage change caused by turning on the switch 1 at the time t ₀ is transmitted to the pulse train generating circuit 8. This pulse train generating circuit 8 operates while the preset switch 1 is on (from time t ₀ to a in FIG. 2a).
It is configured to generate a so-called pulse train that continuously generates pulses (during t ₁ ).

On the other hand, the output of the monomulti 4 is connected to the inverter 5.
is transmitted to. The output waveform of this inverter 5 is shown in FIG. 2c. Reference numeral 6 denotes an AND gate circuit, and the output of the inverter 5 and the output of the pulse train generation circuit 8 are respectively input to two input terminals of the circuit 6. Therefore, the above monomulti 4
During the operation, the AND gate circuit 6 is closed and the pulse train generated from the pulse train generation circuit 8 is not transmitted to the next stage, and the AND gate circuit 6 is opened only after the monomulti 4 has finished its operation, and the pulse train generated from the pulse train generating circuit 8 is not transmitted to the next stage. It can be passed on to the next stage. The output from the gate circuit 6 (see FIG. 2d) is input to the up terminal side of the counter 7, and the count is added by one count each time one pulse of the pulse train is input. This addition operation continues while the preset switch 1 is pressed.

With this structure, when preset switch 1 is pressed once to turn on, the counter 7 will count by 1 for each preset switch operation.
A subtraction operation is performed count by count, and when the preset switch 1 is pressed continuously, an addition operation is automatically performed in accordance with the pulse train shown in FIG. 2d. Therefore, when presetting the count value of the counter 7, first press the preset switch 1 continuously to increase the count content of the counter 7. If the count exceeds the target value at this time, the preset switch 1 By pressing once, you can return the exceeded count value to the target value.

FIG. 3 shows another embodiment of the present invention, in which the pulse train generating circuit 8 is not operated while the monomulti 4 is operating. The parts in FIG. 3 that are numbered the same as in FIG. 1 are the same as in FIG. In the embodiment shown in FIG. 3, when the preset switch 1 is turned on, the monomulti 4 is operated. The output of this monomulti 4 enters the down input terminal of the counter 7, and the count value of this counter 7 is counted down by one count. And while the above MonoMulti 4 is operating,
AND gate circuit 6 is closed and the signal associated with turning on preset switch 1 is not transmitted to pulse train generation circuit 8. However, when the operation of the monomulti 4 is finished, the AND gate circuit 6 to which the output of the inverter 5 and the output of the inverter 9 are input becomes operational in terms of a logic circuit, and operates the pulse train generation circuit 8 at the next stage. . The pulse train generated from this circuit 8 is transmitted to the up input terminal of the up-down counter 7, and the counter 7 counts up by one count each time one pulse of the pulse train is input.

FIG. 4 shows yet another embodiment of the present invention, in which a microcomputer 10 is used to perform operations similar to those described above. FIG. 5 is a flowchart explaining the operation.
The microcomputer 10 has a built-in timer, and when the preset switch 1 is turned on, it counts down the counter 7 by one count and starts the timer. After waiting until the timer reaches a predetermined value, it is determined whether preset switch 1 is on, and if it is on, the counter 7 is counted up, and if it is off, all processing is finished. It's getting old.

Note that in the above embodiment, the addition input and subtraction input to the counter 7 may be switched. In this case, if the preset switch 1 is pressed once, the counter 7 will be incremented, and if the preset switch 1 is pressed continuously, the counter 7 will be decremented.

As explained above, according to the electronic counter preset circuit of the present invention, the counter can be added or subtracted using only one preset switch. It is advantageous in terms of space and cost compared to the conventional one that has each one, and the presetting operation can be performed in only one place, making it easy to perform presetting.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figure 2 is a circuit diagram showing an embodiment of the present invention.
Figures a to d are waveform diagrams explaining the operation, Figure 3 is a circuit diagram showing another embodiment of the invention, Figure 4 is a circuit diagram showing still another embodiment of the invention, and Figure 5 is a circuit diagram showing another embodiment of the invention. It is a flowchart for explaining the operation. 1... Preset switch, 4... Monostable multivibrator, 7... Up/down counter, 8... Pulse train generation circuit, 10... Microcomputer.

Claims (1)

[Claims] 1 A preset switch, comprising one preset switch, a reversible electronic counter with an addition/subtraction function, a timer means activated by the operation of the preset switch, and a pulse train generation means activated by the operation of the preset switch, One pulse associated with one operation of the switch is input to either the addition terminal or the subtraction terminal of the electronic counter, and after the time set by the timer means has elapsed, the output of the pulse train generation means is A preset circuit for an electronic counter configured to input to the other terminal of the addition terminal and the subtraction terminal.