JPH0349124A - Relay malfunction preventing circuit - Google Patents

Abstract

PURPOSE:To prevent the malfunction of a relay by applying the driving current to the relay after detecting that secondary power sources generated by a primary power source have risen. CONSTITUTION:When secondary power sources E21 and E22 generated by a primary power source E1 rise, the base voltage is applied to a transistor TR1 by resistors R1 and R2 of a secondary power source detecting means 20, and TR1 is excited. When TR1 is kept off, TR2 of a primary power source control means 30 is set off because its emitter and base are kept at the same potential. When secondary power sources E21and E22 rise and TR1 is turned on, a current flows through resistors R3 and R4, the base voltage due to the voltage drop across the resistor R3 is generated, and TR2 is turned on. When a control signal is inputted to a relay driving means 40, polarity is reversed by an inverter INV1, TR3 is turned on, and a relay 10 is turned on.

Description

[Detailed Description of the Invention] (Summary) Operating power is supplied from the primary power source to drive the relay,
Regarding the relay malfunction prevention circuit, which is controlled by an electronic circuit that uses a secondary power source generated from the primary power source, "on" and "off" of the relay are used to indicate that the secondary power source generated from the primary power source has started up. To provide a compact, low power consumption, high reliability relay malfunction prevention circuit capable of preventing malfunction of a relay by applying driving power to the relay by a primary power supply control means after detection by a secondary power supply detection means. A secondary power source detection means for detecting that a secondary power source generated from a primary power source has started up and turning the output "on";
A primary power supply control means that controls "on" and "off" of the primary power applied to the relay according to the output of the secondary power supply detection means, and a relay that controls the relay to be turned on and off according to a control signal. and a driving means.

is required.

(Industrial Application Field) The present invention is an electronic circuit in which operating power for driving a relay is supplied from a primary power source, and the relay is turned on and off using a secondary source generated from the primary power source. This invention relates to a relay malfunction prevention circuit that performs control.

Relays are used in various devices, and the primary power source for driving the relay and the secondary power source for the relay control circuit that controls whether the relay is turned on or off are often drawn from separate power sources. many.

In many cases, equipment generates a secondary power source rather than a primary power source, so the startup of the secondary power source is delayed from the startup of the primary power source, so the relay control circuit does not function effectively and the relay It may malfunction.

In order to prevent such relay malfunctions, the circuit configuration is such that the primary power to drive the relay is applied to the relay after the secondary power is turned on. [Conventional technology] Figure 3 explains a conventional example. The figure below shows

The conventional example shown in FIG. 3 includes a relay 10, a primary power source E1, a secondary power source E2. ．． E2□, transistor TR3 that drives relay 10, and inverter I that inputs a control signal to the base of transistor TR3.
NVI, a relay driving means 40 consisting of a resistor R5 that applies a bias voltage to the base of the transistor TR3, and a relay RLA11 and a relay RLB that prevent the relay 10 from malfunctioning.
It is composed of 12.

The control signal input to the relay driving means 40 is inverted by INVI and input to the base of the transistor TR3.

When the base voltage of the transistor TR3 becomes "0" or less, the transistor TR3 turns "on" and the transistor -10
becomes “on”.

At this time, the secondary type aE2. ．． If E2t does not rise, the base voltage of transistor TR3 becomes unstable, which may cause malfunction.

Therefore, the secondary type [E2. , E2t, contacts rla of relay RLAI 1 and relay RLB12, which are driven by E2t.
connect the rib to the relay 10 in series, and the secondary power source E2+,
E2z starts up, relay RLAII, relay RLB
The circuit is configured so that the relay 10 operates after the relay 12 operates, thereby preventing malfunction.

[Problem to be solved by the invention]

In the conventional example described above, in order to prevent malfunction of the relay, a relay operated by a secondary power source is used, which results in large power consumption and a large mounting area, which is more problematic than reliability.

In the present invention, malfunction of the relay can be prevented by applying drive power to the relay by the primary power supply control means after the secondary power supply detection means detects that the secondary power supply generated from the primary power supply has started up. The purpose of the present invention is to provide a relay malfunction prevention circuit that is small in size, has low power consumption, and has high reliability.

[Means to solve the problem]

FIG. 1 shows a block diagram illustrating the invention in detail.

In the block diagram of the principle of the present invention shown in FIG. 1, IO is a relay, El is a primary power source, E2 is a secondary power source generated from the primary power source E1, and 20 is generated from the primary power source E1. 30 is a secondary power supply detection means that detects that the secondary power supply E2 has started up and turns the output "on", and 30 indicates "on" of the primary power supply E+ applied to the relay IO.
, "OFF" according to the output of the secondary power supply detection means 20; 40 is a relay driving means that controls "ON" and "OFF" of the relay 10 according to a control signal; , the provision of such a means is a means for solving this problem.

[Function] The secondary power source detection means 20 detects that the secondary power source E2 has started up and turns the output "on."

This "on" signal causes the primary power supply control means 30 to
"ON", and the primary power source E1 can be applied to the relay 10.

Thereafter, the relay control means 40 turns on and off the relay 10 in accordance with the control signal.

Therefore, since the relay 10 is operated after the secondary power source E2 is turned on, it is possible to prevent malfunction.

〔Example〕

Hereinafter, the gist of the present invention will be specifically explained with reference to FIG. 2, which is a diagram illustrating the present invention in detail.

The embodiment of the present invention shown in FIG. 2 uses the same relay IO as explained in FIG. 1, a primary power source E1, and EL and E2g as secondary power sources generated from the primary power source El.

As the secondary power supply detection means 20 explained in FIG. 1, a transistor TRI and resistors R1 and R2 for setting the bias voltage of the base of the transistor TRI;
Resistors R3 and R4 that set the bias voltage of the base of the transistor TR2, transistor TR3 as the relay driving means 40, a resistor R5 that sets the bias voltage of the base of the transistor TR3, and an inverter INV that inverts the input signal.
This is an example constructed from I.

In the above embodiment, the primary power source E1 is -48V, and the secondary power sources E2+, E2! uses -5V and +5V.

Here, when the secondary power sources E2+ and E2g start up, a base voltage is applied to the transistor TRI by the resistors R1 and R2 of the secondary power source detection means 20, and the transistor TRI becomes r-ON and becomes conductive.

On the other hand, when the transistor TRI is "off", the primary power supply control means 30 is "off" because the emitter and base of the transistor TR2 are at the same potential, and the primary power supply E1 is not visible from the relay IO. It has become.

Secondary power supply E21, E2! rises and transistor TRI turns on, current flows through resistors R3 and R4, so a base voltage is generated due to the voltage drop across resistor R3, transistor TR2 turns on, and relay 10 The primary power supply El is now visible.

Here, when the control signal is input to the relay driving means 40, the inverter INVI inverts the polarity and makes the base voltage of the transistor TR3 below "O" V, so the transistor TR3 becomes conductive and the relay 10 becomes "O" V or less. "On".

In addition, secondary power source E2. , either one of E2□,
When the power does not rise, the transistor TR1 remains in the "off" state, so the relay 10 does not operate.

As mentioned above, the secondary power source E21. ．． By configuring an electronic circuit so that the primary power source E1 for driving the relay is applied after E2□ starts up, it is possible to realize a relay malfunction prevention circuit that is small and has low power consumption and does not malfunction.

〔Effect of the invention〕

According to the present invention as described above, it is possible to provide a relay malfunction prevention circuit that is small in size, has low power consumption, and has high reliability.

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the present invention in detail, FIG. 2 is a diagram explaining the present invention in detail, and FIG. 3 is a diagram explaining a conventional example. In the figure, 10.11 and 12 are relay 20, secondary power supply detection means, 30 is primary power supply control means, 40 is relay drive means, R1-R5 are resistors, TR1NTR3 is transistor, INVI is inverter, El is primary power supply , E2. , E2t are the secondary power sources, respectively. FIG. 2 is a detailed diagram of the present invention. FIG. 1 is a block diagram of the present invention. FIG. 3 is a diagram explaining the conventional example.

Claims (1)

[Claims] The operating power for driving the relay (10) is supplied from the primary power source (E1), and the "on" and "off" states of the relay (10) are generated from the primary power source (E1). A relay malfunction prevention circuit controlled by an electronic circuit using a secondary power source (E2), which detects that the secondary power source (E2) generated from the primary power source (E1) has started up and outputs an output. a secondary power supply detection means (20) that turns on the
The secondary power supply detection means (20) detects whether the primary power supply (E1) applied to the relay (10) is "on" or "off".
primary power supply control means (30) for controlling according to the output of
A relay malfunction prevention circuit comprising: and a relay drive means (40) that controls the relay (10) to be turned on or off using a control signal.