JPH0114935Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an average value circuit.

In order to increase the reliability of the measurement signal, multiple measurement systems are installed at the same measurement point, and the average value of the measurement values of these measurement systems is calculated and adopted as the regular measurement value. When an abnormal value occurs, it is removed and averaged. A conventional example of such an average value circuit is shown in FIG.

In FIG. 1, AV is an average calculation circuit, which receives three input signals E ₁ , E ₂ , and E ₃ through a relay circuit RY, and calculates the average value Eo of these three input signals. The relay circuit RY has six relays RL ₁ , ~RL ₃ , RL ₁ ′ ~ RL ₃ ′, two relays each are connected in series to form three sets of three-way selection circuits, and the average calculation is performed on them. These are provided at each of the three input terminals of the circuit AV. That is, for example, the first input terminal of the average calculation circuit AV is provided with a three-way selection circuit consisting of relays RL ₁ and RL ₂ ' connected in series, and the input signals E ₁ ,
Either one of E ₂ and E ₃ is selected and input to the average calculation circuit AV, and the same applies to the other two input terminals. Normally, input signals E ₁ , E ₂ , and E ₃ are applied to the first, second, and third input terminals of the average calculation circuit AV by the switching contacts of relays _{RL 1} , RL ₂ , and RL _{3 ,} respectively. There is.

The states of the input signals E ₁ , E ₂ , and E ₃ are monitored by monitoring means (not shown), and when an abnormality is detected, the relay RL _i (i=1 to
3) is switched and the abnormal input signal is cut off.
Instead, a normal input signal from another system is given. At this time, relay RL _i ' is also switched in conjunction with relay RL _i , and the signal path corresponding to the abnormal input signal in the other three-way selection circuit is cut off.

In the conventional averaging circuit configured in this way, when an abnormality occurs in any of the input signals, one of the remaining normal input signals is given to the averaging circuit in place of the abnormal input signal. , one of the signals excluding the abnormal signal is given, so
Average calculation can be performed based on signals excluding abnormal signals, and highly reliable measurement values can be obtained.

However, such a conventional average value circuit requires a three-way selection circuit using a relay for each of the three input signal systems, resulting in a complicated configuration of the relay circuit. In particular, if we try to increase the number of input signal systems to four in order to further increase the reliability of measured values, a four-way selection circuit consisting of three relays will be required for each of the four input signal systems, which will cause problems due to the circuit configuration. The complexity also doubles in terms of the relay switching sequence.

The purpose of the invention is to provide an average value circuit with a simple relay circuit.

In the present invention, each of a plurality of input signal systems is provided with a two-choice relay that selects the output signal of the averaging circuit instead of the input signal in the event of an abnormality.

Hereinafter, the present invention will be explained in detail with reference to the drawings.
FIG. 2 is a configuration diagram of an embodiment of the present invention. In FIG. 2, relays RL ₁ , to RL ₄ are provided for each of the four input signal systems, and four input signals E ₁ , respectively are transmitted through the normally closed contacts of these relays.
~ _E4 is given to the average calculation circuit AV. The output signal Eo of the average calculation circuit AV is given to the normally open contact sides of relays RL ₁ and RL ₄ , and the relays
By switching RL _i , the average value output signal Eo can be selected instead of the input signal E _i .

In the average value circuit configured in this way, if an abnormality occurs in either of the input signals E ₁ and ~E ₄ ,
A monitoring circuit (not shown) that detects this switches the relay RL _i of that system, and the average value output signal Eo is input to the average calculation circuit AV instead of the input signal E _i . For example, if the input signal E ₄ becomes abnormal and the relay RL ₄ is switched, then the output signal Eo of the average calculation circuit AV is given by the following equation.

Eo=E ₁ +E ₂ +E ₃ +Eo/4 (1) If we rearrange this equation (1), Eo−Eo/4=E ₁ +E ₂ +E ₃ /4 3/4Eo=E ₁ +E ₂ +E ₃ /4 Eo = E ₁ + E ₂ + E ₃ /3 (2), and the output signal Eo of the average calculation circuit AV is the remaining three input signals E ₁ to _{E 3} excluding the abnormal input signal E ₄ .
is the average value. In the same way, abnormal input signals
, then the average value of the remaining two can be obtained by removing them. That is, measurement values that are not affected by abnormal input signals can be obtained.

In this type of average value circuit, only one relay is provided for each of multiple input systems, so the circuit configuration and relay switching sequence are simple, and even if the input signal systems are increased, the number of relays increases by one. Therefore, the circuit configuration does not become particularly complicated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example, and FIG. 2 is a block diagram of an embodiment of the present invention. RL ₁ , ~RL ₄ ... Relay, AV ... Average calculation circuit.

Claims (1)

[Scope of utility model registration request] an average calculation circuit that has a plurality of input terminals and calculates the average value of a plurality of signals respectively applied to these input terminals; An average value circuit equipped with a two-choice circuit that selects the input signal when the input signal is normal and selects the output signal of the average calculation circuit when each input signal is abnormal and supplies it to the input terminal of the average calculation circuit. .