JP2001283702A - Relay circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay circuit that can reduce consumption of electric current. SOLUTION: This relay circuit comprises a timer power-source circuit TC, a relay RY driven by the application of outputted voltage from the timer power- source circuit TC, a transistor for relay drive Tr1 which is connected in series with the relay RY and constitutes a series circuit for relay drive 1 together with the relay RY, a resistor R1 which is connected to the timer power-source circuit TC and also connected with the transistor for relay drive TR1 so as to supply its base current, a transistor for bypass Tr2 which is connected in series with the resistor R1 so as to constitute a series circuit for bypass 2 connected in parallel with the series circuit for relay drive 1, a timer T which is connected in series with the series circuit for relay drive 1 and outputs an output signal after a lapse of a prescribed time from the start of input of an input signal, and a transistor for control Tr3 which controls base current for the transistor for bypass Tr2, by being switching-controlled by the output signal outputted from the timer T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay circuit having a timer.

[0002]

2. Description of the Related Art Conventionally, as a relay circuit of this kind, FIG.
The circuit shown in FIG. This relay circuit will be described below.

[0003] TC is a timer power supply circuit which is supplied with an AC voltage and outputs a predetermined voltage V0 as an output voltage. Ry
Is a relay, one end of which is connected to the timer power supply circuit TC, and the other end of which is a third transistor Q3 described later.
Is connected to the timer power supply circuit TC. The relay Ry is driven by application of the output voltage of the timer power supply circuit TC when a third transistor Q3 described later is turned on.

Q1 is a first transistor whose collector is connected to a timer power supply circuit TC via a third resistor r3, whose emitter is also connected to the timer power supply circuit TC, and whose base is connected to a second resistor r2. The output terminal OUT is connected to an output unit OUT of a timer T described later.

A second transistor Q2 has a collector connected to the timer power supply circuit TC via a fourth resistor r4, an emitter also connected to the timer power supply circuit TC, and a base connected to the first transistor Q1. It is connected to a connection point with the third resistor r3.

[0006] Q3 is a third transistor, a relay Ry
Connected to the timer power supply circuit TC via
The emitter is also connected to the timer power supply circuit TC, and the base is connected to the connection point between the second transistor Q2 and the fourth resistor r4.

A Zener diode ZD has a cathode connected to the timer power supply circuit TC via the first resistor r1, and an anode connected to the timer power supply circuit TC.

T is a timer whose input IN is connected to the connection point between the cathode of the Zener diode ZD and the first resistor r1, and whose output OUT is connected to the first transistor Q1 via a fifth resistor r2. Connected to the base. The timer T outputs an output signal from the output unit OUT after a predetermined time has elapsed after an input signal including a Zener voltage of the Zener diode ZD is applied to the input unit IN.

Next, the operation will be described. When the timer power supply circuit TC outputs the predetermined voltage V0 as an output voltage, the first resistor r1 is connected to the input section I of the timer T while the zener voltage of the zener diode ZD is applied to the timer T.
N to supply the input signal current. As a result, the timer T
Starts a so-called timed operation for counting time after the input signal current starts to be input.

On the other hand, the bypass transistor Tr2 is
When the timer power supply circuit TC outputs the predetermined voltage V0 as the output voltage, the base voltage is supplied through the third resistor r3 to conduct. Thus, the second transistor Q
The conduction of 2 causes a bypass current to flow through the fourth resistor r4 and the second transistor Q2.

Further, since a current flows through the second transistor Q2 and the fourth resistor, the third transistor Q3
No base voltage is supplied through the fourth resistor r4 and the fifth resistor r5.

Thereafter, when a predetermined time has elapsed since the time counting was started, the timer T outputs an output signal voltage,
The output signal voltage becomes the base voltage, and the first transistor Q1 conducts. As described above, when the first transistor Q1 is turned on, current flows through the first transistor Q1 and the third resistor r3, and the base voltage is not supplied to the second transistor Q2.

As a result, since the second transistor Q2 is cut off, the bypass current stops flowing, and the third transistor Q2 is turned off.
The transistor Q3 is supplied with a base voltage via the fourth resistor r4 and the fifth resistor r5 to conduct. As described above, when the third transistor Q3 is turned on, the relay Ry is driven by the application of the predetermined voltage V0 from the timer power supply circuit TC.

[0014]

In the above-mentioned conventional relay circuit, the resistance value of the fourth resistor r4 is set to the value of the relay R.
By making the resistance value substantially equal to the resistance value of the timer y, the bypass current flowing while the timer T is counting the time and the drive current for driving the relay Ry after a lapse of a predetermined time after the timer T has counted the time are calculated. Almost equal, relay R
Irrespective of the driving and stopping of y, there is an advantage that the output of the timer power supply circuit TC can be stabilized, the voltage supplied to the timer T can be stabilized, and malfunction can be prevented.

However, since the bypass current continues to flow even before the lapse of the predetermined time at which the timer T finishes counting the time, the relay circuit does not operate during the predetermined time during which the timer T is counting the time. In addition, there is a problem in that the input signal current flows and the current consumption increases.

The present invention has been made in view of the above points, and an object of the present invention is to provide a relay circuit consuming less current.

[0017]

According to another aspect of the present invention, there is provided a relay circuit comprising: a timer power supply circuit; a relay driven by application of an output voltage from the timer power supply circuit; A relay driving transistor connected between the relay in series to form a relay driving series circuit with the relay, a resistor connected to the timer power supply circuit and connected to supply the base current to the relay driving transistor, A bypass transistor whose collector and emitter are connected in series to a resistor so as to form a bypass series circuit connected in parallel with the relay drive series circuit, and a predetermined time after an input signal is input in series with the relay drive series circuit and the input signal is started to be input. Opening / closing control by a timer that outputs an output signal after elapse and an output signal output from the timer A control transistor that controls the base current to the bypass transistor is, is configured to include a.

According to a second aspect of the present invention, in the relay circuit of the first aspect, the resistance is set such that a current of the series circuit for bypass is smaller than a current of the series circuit for driving the relay. Configuration.

According to a third aspect of the present invention, in the relay circuit of the second aspect, a capacitor and a zener diode are connected in parallel with the timer.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A relay circuit according to a first embodiment of the present invention will be described below with reference to FIG.

TC is a timer power supply circuit which is supplied with an AC voltage and outputs a predetermined voltage V0 as an output voltage.

A relay RY has one end connected to an input section IN of a timer T described later and the other end connected to a timer power supply circuit TC via a relay driving transistor Tr1 described later. The relay RY is driven by application of a predetermined voltage V0 which is an output voltage from the timer power supply circuit TC, when a relay driving transistor Tr1 described later is turned on.

R1 is a first resistor, which is a timer power supply circuit T
C and connected so as to supply the base current to a relay driving transistor Tr1 described later.

R2 is a second resistor, like the first resistor R1, connected to the timer power supply circuit TC and connected to supply a base current to a bypass transistor Tr2 described later.

Tr1 is a relay driving transistor whose collector is connected to the timer power supply circuit TC, whose emitter is connected to the relay RY, and which forms a relay driving series circuit 1 together with the relay RY, and whose base is the first. It is connected to the resistor R1.

Tr2 is a bypass transistor, the collector of which is connected to the first resistor R1 and the second resistor R2.
2 together with the bypass series circuit 2, the emitter is input to the input unit IN of the timer T described later, and the base is the second resistor R2 and the control transistor T described later.
It is connected to the connection point of r3 with the collector. The bypass series circuit 2 including the bypass transistor Tr2
Are connected in parallel to the relay driving series circuit 1.

Tr3 is a control transistor. The collector is connected to the connection point between the second resistor R2 and the base of the bypass transistor Tr2, the emitter is connected to the timer power supply circuit TC, and the base is the third resistor. R3
Is connected to an output section OUT of the timer T described later. Therefore, the control transistor Tr3 is
The output signal output from the timer T controls the opening and closing between the collector and the emitter. As a result, the base current to the bypass transistor Tr2 is controlled.

T is a timer (timer IC) whose input section IN is connected to a relay driving series circuit 1 and also connected in series to a bypass series circuit 2 connected in parallel to the relay driving series circuit 1. Then, via these relay driving series circuit 1 and bypass series circuit 2,
It is connected to the timer power supply circuit TC. The output terminal OUT of the timer T is connected to the base of the control transistor Tr3 via the third resistor R3.

This timer T has a timer power circuit TC
In the state where the predetermined voltage V0 which is the output voltage is applied, the output signal voltage is output after a lapse of a predetermined time from the start of input of the input signal current i3 from the timer power supply circuit TC.

Next, the operation will be described. The timer power supply circuit TC outputs a predetermined voltage V0 (for example, 12
V), the first resistor R1 connected to the timer power supply circuit TC supplies the base current to the transistor Tr1 for driving the relay.
, Supplies the base current to the bypass transistor Tr2.

At this time, since the collector and the emitter of the control transistor Tr3 are cut off, the collector and the emitter of the bypass transistor Tr2 to which the base current is supplied become conductive, so that the relay driving transistor Tr1 is turned on. The base current supplied to the transistor Tr1 decreases, so that the collector-emitter of the transistor Tr1 for relay driving is cut off.

In this state, an input signal current i3 from the timer power supply circuit TC is input to the timer T through a bypass series circuit 2 which is connected in parallel with the relay drive series circuit 1 and forms a so-called bypass circuit. , Timer T
Starts a so-called timed operation for counting time after the input signal is started to be input. During this time, the bypass current i2 continues to flow in the bypass circuit including the bypass series circuit 2.

When a predetermined time has elapsed since the start of counting the time, the timer T outputs an output signal voltage, and the output signal voltage becomes a base voltage, and the control transistor T
A base current is supplied to r3, and conduction between the collector and the emitter of the control transistor Tr is conducted. Thus, when the collector-emitter conduction of the control transistor Tr3 is conducted,
The base current is no longer supplied to the bypass transistor Tr2, and the collector-emitter connection of the bypass transistor Tr2 is cut off.

As a result, the current flowing through the first resistor R1 is supplied to the relay driving transistor Tr1 as a base current, and the bypass current i2 stops flowing through the bypass series circuit 2 forming the bypass circuit. Conduction occurs between the collector and the emitter of Tr1. As described above, when the relay driving transistor Tr1 is turned on, a predetermined voltage V0 is applied as an output voltage from the timer power supply circuit TC, and a relay driving current i1 for driving the relay RY flows through the relay driving series circuit 1, and RY
Is driven.

In such a relay circuit, the timer T
, An input signal current i3 is input through a bypass series circuit 2 which is connected in parallel to a relay driving series circuit 1 and forms a so-called bypass circuit, and after a predetermined time elapses after the input signal current i3 starts being input. An output signal voltage is output, and the control transistor Tr is output by the output signal voltage.
After the base transistor is controlled by the switch and the opening and closing of the bypass transistor Tr is controlled, the input signal current i3 is input to the timer through the relay driving series circuit 1 including the relay RY. Since the input signal current i3 to the timer T itself flows through the bypass series circuit 2 forming a so-called bypass circuit until a predetermined time elapses after the input signal starts being input, the current consumption can be reduced. .

Next, a second embodiment of the relay circuit of the present invention will be described below with reference to FIG. Only different points from the first embodiment will be described. This embodiment is basically the same as the first embodiment, except that the resistance value of the first resistor R1 is equal to the bypass current i flowing through the bypass series circuit 2.
2 is set to be smaller than the relay driving current i1 flowing through the relay driving series circuit 1, and furthermore, the capacitor C and the Zener diode ZD are connected in parallel with the timer T, respectively.

The Zener diode ZD has its cathode connected to the timer power supply circuit TC via the relay driving series circuit 1 or the bypass series circuit 2,
The anode is directly connected to the timer power supply circuit TC, and the voltage applied to the timer T is changed by the Zener diode ZD.
Is the Zener voltage VZ of

In such a relay circuit, the resistance value of the first resistor R1 is set so that the current flowing in the bypass series circuit 2 is smaller than the current flowing in the relay driving series circuit 1. A series circuit for a bypass is used as an input signal to be input to the timer T until a predetermined time elapses after the input signal is input to the timer T, that is, until the relay RY is driven after the input signal is input to the timer T. Since the current flowing through the relay circuit 2 can be reduced, the effect of the relay circuit of the first embodiment that the current consumption can be reduced can be further achieved.

Even if the current flowing in the bypass series circuit 2 is smaller than the current flowing in the relay driving series circuit 1, the capacitor T and the Zener diode ZD are connected to the timer T in parallel. Therefore, the voltage supplied to the timer T can be stabilized to prevent malfunction.

[0040]

According to the relay circuit of the present invention, an input signal is input to the timer through a bypass series circuit which is connected in parallel with the relay driving series circuit and forms a so-called bypass circuit. After a lapse of a predetermined time from the start of input, an output signal is output. After the base transistor is controlled by the control transistor by the output signal and the opening and closing of the bypass transistor is controlled, the output signal passes through a relay driving series circuit including a relay. Since the input signal is input to the timer, unlike the conventional example, the input signal itself to the timer flows through a bypass series circuit forming a so-called bypass circuit until a predetermined time elapses after the input signal is input. Therefore, current consumption can be reduced.

In the relay circuit according to the second aspect, the resistance value of the resistor is set so that the current flowing in the bypass series circuit is smaller than the current flowing in the relay driving series circuit. Since a predetermined time has elapsed since the start of the input, that is, from when the input signal began to be input until the relay is driven, the current flowing through the bypass series circuit as the input signal input to the timer can be reduced. The effect of claim 1 that the current consumption can be reduced can be further achieved.

In the relay circuit according to the third aspect, in addition to the effect of the relay circuit according to the second aspect, even if the current flowing through the bypass series circuit is smaller than the current flowing through the relay driving series circuit. Since the capacitor and the Zener diode are connected in parallel to the timer, the voltage supplied to the timer can be stabilized to prevent malfunction.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a second embodiment of the present invention.

FIG. 3 is a circuit diagram of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 relay driving series circuit 2 bypass series circuit C capacitor R1 first resistor RY relay T timer TC timer power supply circuit Tr1 relay driving transistor Tr2 bypass transistor Tr3 control transistor ZD Zener diode

Claims (3)

[Claims] 1. A timer power supply circuit, a relay driven by application of an output voltage from the timer power supply circuit, and a relay driving transistor connected between the collector and the emitter in series with the relay to form a relay driving series circuit together with the relay. A resistor connected to the timer power supply circuit and connected to supply the base current to the relay driving transistor, and a resistor between the collector and the emitter forming a bypass series circuit connected in parallel with the relay driving series circuit. A bypass transistor connected in series to a relay driver, a timer connected in series to the relay driving series circuit and outputting an output signal after a lapse of a predetermined time from the start of input of an input signal, and an opening / closing controlled by an output signal output from the timer. A control transistor for controlling a base current to the bypass transistor; A relay circuit comprising: 2. The relay circuit according to claim 1, wherein the resistance is set to a value such that a current of the bypass series circuit is smaller than a current of the relay driving series circuit. 3. The relay circuit according to claim 2, wherein a capacitor and a Zener diode are respectively connected in parallel with said timer.