JPS63236406A - Pulse generation circuit - Google Patents

Abstract

PURPOSE:To simplify constitution and to control pulse width and a duty ratio, by inserting two variable resistors in a multivibrator constituted of a NAND circuit and two inversion circuits. CONSTITUTION:The variable resistors 26 and 27 are used as resisters which constitute the RC charge/discharge circuit of the multivibrator consisting of one NAND circuit 21 and the two inversion circuits 22 and 23 connected in series, and one ends of the two variable resistors 26 and 27 are connected to the output terminal of the inversion circuit 23 via diodes 24 and 25 set in reverse directions to each other, and the other ends to the input side of the inversion circuit 23 via a capacitor 28. A time constant at the time of charging the capacitor 28 is decided by the variable resistor 26 and at the time of discharging, it is decided by the variable resistor 27, therefore, it is possible to control the width T1 of a generated pulse signal and the generation interval T2 of a pulse independently respectively and freely.

Description

[Detailed Description of the Invention] [Summary] In conventional pulse generation circuits, it is difficult to control the pulse width and duty ratio separately. Therefore, two variable resistors are inserted into the multi-by-break to simplify the pulse generation circuit, which allows the pulse width and duty ratio to be freely controlled.

[Industrial application field]

The present invention relates to a control circuit built into an electromagnetic relay, and more particularly to a pulse generation circuit that can freely control pulse width and duty ratio.

Electromagnetic relays have the advantage of being able to easily control relatively large currents compared to switching elements made of semiconductor integrated circuits, etc., and are used by being incorporated into control circuits of various electronic devices. However, unlike a switching element made of a semiconductor integrated circuit or the like, there is a problem in that it requires a dedicated control circuit to control it and is difficult to use. As a means to solve this problem, electromagnetic relays with built-in control circuits are being developed.

However, the circuits that control electromagnetic relays, whose operating and stopping times vary greatly depending on the application, can control the pulse width and duty ratio freely, and are equipped with pulse generation circuits that can be easily configured to fit into limited spaces. There must be. Therefore, it is desired to realize a pulse generation circuit that has a simple configuration, can freely control the pulse width and duty ratio, and is inexpensive.

[Conventional technology]

FIG. 2 is a circuit diagram showing an example of a conventional pulse generating circuit, and FIG. 3 is a time chart showing the operation of the pulse generating circuit.

In Fig. 2, the conventional pulse generation circuit that can control the pulse width and duty ratio consists of three NAND circuits 11 and 12.
．． The capacitor 17 is charged by using a variable resistor 14 as a part of the resistor constituting the RC charging/discharging circuit of the multi-bye break using 13, and by connecting two diodes 15 and 16 in series on both sides of the variable resistor 14. time and capacitor 1
7 changes the time constant when discharging.

That is, the resistances of the divided variable resistors 14 are each 14a.
, 14b, the time constant when charging the capacitor 17 is determined by the total value of the fixed resistor 18 and the dividing resistor 14a, and the time constant when the capacitor 17 is discharging is determined by the total value of the fixed resistor 18 and the dividing resistor 14b. .

As a result, the input terminal 11a of the NAND circuit 11 at the top receives a signal indicated by ■ in FIG. 3, and the output terminal 19a of the NAND circuit 19 generates a pulse signal indicated by ■ in FIG.

[Problem that the invention seeks to solve]

The conventional pulse generating circuit can control the pulse width and duty ratio of the pulse signal by changing the resistance of the variable resistor 14 as described above.

However, the total value of the dividing resistor 14a and the dividing resistor 14b is always constant, and the sum T of the width T1 of the generated pulse signal and the pulse generation interval T2 is constant, and the pulse width and duty ratio cannot be controlled separately. There was a problem.

[Means for solving problems]

FIG. 1 is a circuit diagram showing an embodiment of a pulse generating circuit according to the present invention.

The above problem is caused by at least one NAN connected in series.
It has a D circuit 21 and two inverting circuits 22 and 23, and through diodes 24 and 25 through which current flows in opposite directions,
2 (11il variable resistor 26, one end of 27 is connected to inverting circuit 2
3, and the variable resistors 26.
The other end of the variable resistor 26.27 and the input side of the inverting circuit 23 are connected via a capacitor 28, and the other end of the variable resistor 26.27 and the input side of the NAND circuit 21 are connected via a resistor 29. This problem is solved by the pulse generating circuit of the present invention.

[Effect]

In FIG. 1, a NAND circuit 21 and two inverting circuits 22
．． By inserting two variable resistors that can be operated separately into the multivibrator consisting of 23 and changing the time constants when charging the capacitor 28 and when discharging the capacitor 28, the pulse width and duty ratio can be freely controlled. It is possible to form a simplified pulse generation circuit that can be controlled precisely.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, the pulse generating circuit according to the present invention includes one NAND circuit 21 and two inverting circuits 2 connected in series.
Using a variable resistor 26.27 as a resistor that constitutes an RC charging/discharging circuit of a multi-bye break consisting of 2.23,
One end of the two variable resistors 26 and 27 is connected to the inverting circuit 23 through diodes 24 and 25 through which current flows in opposite directions.
By connecting the other ends of the variable resistors 26 and 27 to the input side of the inverting circuit 23 via the capacitor 28, when the capacitor 28 is charged and when the capacitor 28 is discharged, R with different time constants
A C charging/discharging circuit can be constructed.

In other words, the time constant when charging the capacitor 28 is the variable resistor 2.
6, and the time constant when the capacitor 28 discharges is determined by the variable resistor 27. As a result, N is connected via the resistor 29 to the other end of the variable resistor 26.
A signal indicated by ■ in FIG. 3 is input to the input terminal 21a of the AND circuit 21, and a third
A pulse signal indicated by ■ in the figure is generated. Unlike conventional pulse generating circuits, this pulse generating circuit can operate the two variable resistors 26 and 27 separately, so that the width T1 of the generated pulse signal and the pulse generation interval T2, that is, the pulse width and the duty ratio There is no correlation between the two, making it possible to freely control the pulse width and duty ratio over a wide range.

Note that the inverting circuits 32 and 33 inserted between the other input side of the NAND circuit 21 and the power supply VDD are connected to the power supply VDD.
A switch 34 connected to the input side of the inversion circuit 32 is used to fix the pulse signal at the level GND.

In this way, by inserting two variable resistors that can be operated separately into the multi-by-break, which is composed of a NAND circuit and two inverting circuits, and changing the time constants when charging and discharging the capacitor. , it is possible to form a simplified pulse generation circuit in which the pulse width and duty ratio can be independently and freely controlled.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a pulse generation circuit in which the pulse width and duty ratio can be controlled independently and freely.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the pulse generation circuit according to the present invention, Fig. 2 is a circuit diagram showing an example of a conventional pulse generation circuit, and Fig. 3 is a time chart showing the operation of the pulse generation circuit. , is. In the figure, 21 is a NAND circuit, 21a is an input terminal, 22.23
is an inverting circuit, 24.25 is a diode, 26.27 is a variable resistor, 28 is a capacitor, 29 is a resistor,
31, 32, and 33 are inverting circuits, 31a is an output terminal,
34 represents a switch. Invention 1: The result of the n-circuit in the present invention) Figure 1 shows a row of the conventional pulse current circuit Figure 2

Claims (1)

[Claims] At least one NAND circuit (21
) and two inverting circuits (22, 23), through diodes (24, 25) through which current flows in opposite directions,
One end of the two variable resistors (26, 27) is connected to the inverting circuit (2
3), and the variable resistor (
The other ends of the variable resistors (26, 27) and the input side of the inverting circuit (23) are connected via a capacitor (28), and the other ends of the variable resistors (26, 27) and the NAND circuit (21) are connected to each other via a capacitor (28). A pulse generating circuit characterized in that the pulse generating circuit is connected to the input side of the circuit via a resistor (29).