JPH0142271Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention relates to a selection relay output circuit that obtains a contact output according to a coded selection signal.

<Prior Art and Problems> This type of conventional circuit is shown in FIG. 1 or 2. In FIG. 1, a decoder 1 decodes a coding selection signal and a corresponding selection relay 2 ₁
Drive at least one relay 2 ₁ ~ _{2 o}
Each contact 3 ₁ to 3 _o is the common terminal COM and output terminal
Connected to OUT ₁ to OUT _o and taken out as contact output. In this circuit, in order to increase the contact output capacity (current breaking capacity), it is possible to use a relay with a large contact capacity for each relay.
The larger size of the relay itself creates problems in terms of mounting space and cost.

In Fig. 2, the contact ₄₁ of the power relay 4 with a large contact capacity is provided as a common output contact between the contacts ₃₁ to _{3o of each relay 21 to 2o and the} common terminal COM, and the drive of this relay 4 is controlled by timing. The circuit 5 is configured to control the timing shown in FIG.
That is, the timing circuit 5 obtains the timing of the selection signal from the decoder 1 and drives the relay 4 to close the contact 4 ₁ after the contact closing operation of the selection relays 2 ₁ to 2 _o , and conversely, before the selection relay opens. Contact 4
By driving relay 4 to open ₁ and having contact 4 ₁ of relay 4 handle the switching of the output current,
For the selection relays 2 ₁ to 2 _o , it is possible to use relays with a small current breaking capacity at their contacts.

However, in the circuit shown in FIG. 2, the timing circuit 5 requires a large number of auxiliary relays and timers, making the circuit complex, and readjustment is required in response to changes in the timing relationship between the selection code and the selection relay. It is inferior in _versatility , as it requires a

<Purpose of the invention> An object of the invention is to provide a selection relay output circuit that ensures the operation timing of the power relay and selection relay and also allows easy changes.

<Summary of the invention> The invention is characterized in that the control of the power relay and selection relay is programmed and processed by a microcomputer.

<Embodiment> FIG. 4 is a circuit configuration diagram showing an embodiment of the present invention. The power relay 4 and the selection relays 2 ₁ to 2 _o are connected so that the contact 4 ₁ is a common output contact and the contacts 3 ₁ to 3 _o are selection output contacts. The power relay 4 and the selection relays 2 ₁ to 2 _o are driven as respective channel outputs of the digital output circuit 7 of the microcomputer 6. Digital input circuit 8 takes in the selection signal. The microcomputer 6 includes a digital output circuit 7, an input circuit 8, a CPU 9, and a memory 1.
0 and the CPU 9 connects the relay 2 ₁ corresponding to the selection signal according to the program in the memory 10.
~2 Select and control _o , and use power relay 4 for that control.
Controls the operation timing.

The control mode of the microcomputer 6 will be explained below with reference to the time chart of FIG. Selection signal (third
t ₁ ) in the figure indicates each selection relay 2 ₁ to 2 _o in the CPU 9.
The selected relay is determined by comparing it with the code assigned to (decoding function). Next, a channel output corresponding to the selected relay is outputted from the digital output circuit 7, and the selected relay is driven. By driving this selection relay, the CPU 9 controls the drive of the power relay 4 through the output circuit ₇ with a delay of the time T _{1 from the data of the time T 1} required for the contact state to change (time t ₂ ).
When the contact 4 ₁ of the power relay 4 is on, the contact of the selected relay is already closed, and when the contact of the relay 4 is on (time t ₃ ), the output terminals OUT ₁ to OUT _o
External output can be obtained from at least one of the.

Next, when the selection signal is stopped (time t ₄ ),
CPU 9 first stops driving power relay 4,
Time required for contact 4 ₁ of power relay 4 to open T ₂
Based on the data, the selected selection relay is stopped driving with a delay of the time T ₂ (time t ₅ ). Therefore, when the contact of the power relay 4 is opened (time t ₆ ), the contact of the selection relay is still closed, and the external output by the power relay is cut off.

<Effects of the invention> According to the invention, a series-connected power relay contact is provided in common to the selection relay contacts, the external output is opened and closed by opening and closing the power relay contact, and the selection relay contact selects the external output. In the selection relay output circuit, the drive conditions and timing processing for the power relay and selection relay are obtained from the time (T ₁ , T ₂ ) data required for the operation of the power relay and selection relay, so a simple program can be used to ensure reliable timing. This makes it a highly versatile circuit because it can handle changes in the specifications of each relay by simply changing its operating time data. In addition, when the microcomputer functions as a control center for external output target equipment, it is equipped with relay control and decoding functions as part of its functions.
To eliminate the need to specially prepare a control means for a relay output circuit.

In the embodiment, it is sufficient to provide an element such as a surge absorbing diode, varistor, surge killer, etc. at the output contact only at the power relay contact ₄₁ .

[Brief explanation of drawings]

1 and 2 are conventional selection relay output circuit diagrams, FIG. 3 is a time chart in FIGS. 2 and 4, and FIG. 4 is a circuit diagram showing an embodiment of the present invention. 2 ₁ , 2 ₂ , 2 _o ... selection relay, 4 ... power relay, 6 ... microcomputer, 7 ... digital output circuit, 8 ... digital input circuit,
9...CPU, 10...Memory.

Claims (1)

[Scope of utility model registration request] In a selection relay output circuit that drives at least one of the plurality of selection relays in response to a coded selection signal and obtains the contact output of the selection relay as an external output, the selection relay is commonly connected in series to each contact of the selection relay. A power relay with large capacity contacts,
This power relay includes a microcomputer having an output circuit capable of driving the selection relay and an input circuit capable of inputting the selection signal, and the microcomputer selectively drives and stops driving the selection relay according to the encoded selection signal. , the power relay is driven with a delay of time T ₁ from the data of the time Ti required for the contact operation of the relay from the selection drive of the selection relay, and the drive of the power relay is stopped to stop the drive of the selection relay. 1. A selection relay output circuit characterized in that the selection relay is configured to stop driving the selection relay with a delay of time T ₂ from data of time T ₂ required for contact operation of the relay.