JPS6241540Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an operating time display output circuit for displaying the operating status of the circuit breaker or breaker at a remote location in a circuit breaker or breaker having an overcurrent tripping mechanism using an electronic circuit. It is something.

FIG. 1 is a circuit diagram showing an example of a conventional output circuit of this type. In the figure, 1 is the track, 2 is the track 1
3 is a timer circuit, 4 is a switching element that operates in response to a signal from the timer circuit 3, 5 is an opening/closing mechanism, 6 is an operation display device, and 7 is a tripping coil.

Next, to explain its operation, the current flowing in the line 1 is constantly detected by the current transformer 2 and the information is sent to the time limit circuit 3. When the current flows, one of the plurality of output terminals of the time limit circuit 3 outputs a control signal according to the passage time of the overcurrent,
One of the connected switching elements 4 is turned on. When one of the switching elements 4 is turned on, the tripping coil 7 connected thereto is energized, and the opening/closing mechanism 5 is operated by the attractive force of this coil, and the line 1 is cut off. In order to display which switching element 4 has operated in the above-mentioned operation, an operation display device 6 is connected to the anode of the switching element 4 for each switching element 4, and in order to display this at a remote location. A lead wire was drawn for each operation display device 6, and the output was displayed.

In such a conventional configuration, in order to display the operation display of the switching element 4 as described above at a remote location, it is necessary to draw lead wires corresponding to the number of operation display devices 6 (in the example of FIG. (4 wires) Also, reliability was inevitably lowered due to longer lead wires.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and provides an output circuit that can display the operating status of a plurality of switching elements 4 using two lead wires without affecting the main line disconnection circuit. It is an object.

An embodiment of this invention will be described with reference to the drawings. Second
The figure is a circuit diagram showing an embodiment of this invention, and the same reference numerals as in Fig. 1 indicate the same or corresponding parts. With the removal coil 7,
A backflow blocking diode connected between the switching element 4, 12, a backflow blocking diode 13a corresponding to a Zener diode 13 to be described later;
13b and 13c are Zener diodes, and 14 is a common output terminal. Each Zener diode 13a, 1
3b and 13c have different Zener voltages, the Zener diode 13a is connected in series with the switching element 4a, the Zener diode 13b is connected in series with the switching element 4b, and the Zener diode 13 is connected in series with the switching element 4b.
c are connected in series with the switching element 4c between the output terminals 14 via diodes 12, respectively.

Next, the operation of the circuit shown in FIG. 2 will be explained. Voltage is applied to the output terminal 14 from a remote display device, and the switching elements 4a, 4b,
When all 4c are in the off state, output terminal 14
The voltage between is equal to the applied voltage. For example, when a voltage of 20V is applied from a remote display device, Zener diode 13a is 15V, 13b is 10V, and 13c is 5V.
When the switching elements 4a, 4b, and 4c are all in the OFF state, the voltage at the output terminal 14 is 20V. When the current in the line 1 increases and the timer circuit 3 operates, and the switching element 4a is short-circuited, the switching element 4a, the diode 12, and the Zener diode 13a are connected.
Current flows through the series circuit with the terminal 14, and the voltage at terminal 14 is 15V.
becomes. Similarly to the above, for example, switching element 4
When b is short-circuited, the voltage at the output terminal 14 becomes approximately 10V due to the Zener diode 13b. In this manner, by applying a voltage to the output terminal 14 from the remote display device, a voltage corresponding to the operating state of the switching element 4 is outputted to the output terminal 14. Since the operation can be displayed by monitoring this output voltage with a remote display device, the common terminal 14 can be led to a remote location using two lead wires, and the operation can be displayed at that point.

In the above embodiment, there are three types of operation indications, but any number may be used, and no matter what the Zener voltage is, there is no problem as long as they are set to different voltages.

As described above, according to this invention, by combining a diode and a Zener diode, an operating time display output circuit can be easily constructed with a minimum number of lead wires, and reliability and economical effects can be achieved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing an example of a conventional device; Figure 2 is a circuit diagram showing an example of a conventional device;
The figure is a circuit diagram showing an embodiment of this invention. DESCRIPTION OF SYMBOLS 1...Line, 2...Current transformer, 3...Timed tripping circuit, 4...Switching element, 5...Opening/closing mechanism, 6...Operation display mechanism, 7...Tripping coil, 11, 12... ...Diode, 13...Zena diode, 14...Output terminal. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] An overcurrent detection circuit detects overcurrent, and the overcurrent detected by this overcurrent detection circuit is divided into multiple current stages, and the current is output from each output terminal after a predetermined duration corresponding to each current stage. A timer circuit that outputs a control signal, a plurality of switching elements to which the control signals from the respective output terminals of the timer circuit are respectively input, and a circuit for each switching element on the anode side of the plurality of switching elements. a tripping coil energized by a circuit in which a plurality of diodes for reverse current blocking are each connected in series, and a plurality of series circuits of the diodes and corresponding switching elements are all connected in parallel; A zener diode having a zener voltage determined corresponding to each switching element of the plurality of switching elements is connected in series with a reverse current blocking diode between a common power source and each corresponding switching element. An output circuit with an output circuit and an operating time display output circuit for circuit breakers.