JPH0228831B2 - DENKIRYOKENSHUTSUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a quantity of electricity detection device for detecting whether an input quantity of electricity is equal to or greater than a predetermined value, and particularly relates to a detection device for an amount of alternating current electricity.

Conventionally, as a simple electric quantity detection device, for example, there is a method of detecting whether the input is above a predetermined value based on whether the instantaneous value of the full-wave rectified wave of AC input is above a predetermined value or whether it is longer than a predetermined time. It was common.

A conventional electric quantity detection device will be explained below with reference to FIGS. 1 and 2. Fig. 1 is a block diagram showing an example of a conventional electric quantity detection device, where I is an input terminal to which an alternating current electric quantity V is applied, 1 is a full-wave rectifier circuit, 2 is a level detection circuit, and _T1 is an operating time. _T1 is a timer circuit whose return time is zero, _T2 is a timer circuit whose operating time is zero and return time is _T2 , and O is an output terminal. V ₁
is of rectifier circuit 1, V ₂ is of level detection circuit 2,
VT ₁ is of timer circuit T ₁ , V _p is of output terminal O,
Each is an output waveform.

Fig. 2 is an explanatory diagram of the operation of the conventional device shown in Fig. 1, where the left part A shows the case where the input electricity amount is less than the set value and it is inactive, and the right part B shows the case where the input electricity amount is more than the set value and it is in operation. . In the case of Fig. 2 A, the period t ₁₁ during which the output V ₁ of the rectifier circuit 1 exceeds the detection level V _L of the level detection circuit ₂ is shorter than the set time T ₁ of the timer circuit T ₁ . Since no output is generated, no output is sent from output terminal O.

In the case of FIG. 2B, the period _t12 during which the output V1 of the rectifier circuit ₁ exceeds the detection level _VL of the level detection circuit 2 is longer than the set time _T1 of the timer circuit _T1 , so _T12 is longer than the timer circuit _T1 . A pulse output with a time width of _-T1 is generated once every 1/2 cycle, made continuous by the timer circuit _T2 , and continuously outputted to the output terminal O. Here, the operating time T ₁ of the timer circuit T ₁ is, for example, T ₁ = π/2 = 5 ms (on a 50 cycle basis)
Set to . In this case, if the detection level of the level detection circuit 2 is V ₂ , √2Vsinπ−π/2/2=√2Vsinπ/4=V≧V _L , and whether the effective value V of the input electric quantity is larger than V _L or not. It will be detected whether

Also, the recovery time T ₂ of the timer circuit _{T 2 is} T ₂ = 1/2 + α (α
is the margin time) For example, T ₂ = 1 cycle = 20ms (50
cycle-based).

The conventional electric quantity detection device is configured as described above, and can operate normally when the input electric quantity V is a sine wave input. However, if the input electric quantity V has waveform distortion, the input electric quantity A major drawback was that it could not operate even though V was greater than the set value V _L .

In other words, in Fig. 3, the input electricity quantity V is the set value.
Regardless of the fact that it should normally operate at a magnitude greater than or equal to V _L , if a crack occurs in the input electrical quantity V, a crack also occurs in the output V ₂ of the level detection circuit 2, and for this reason, the timer circuit T ₁ Since a pulse output cannot be generated, the output V _p is not output.

This invention was made in order to eliminate the drawbacks of the conventional electric quantity detection device as described above. By using an integrating circuit in place of the timer circuit _T1 , input electric power is reduced by distorted waves and waveform disturbances. It is an object of the present invention to provide a highly reliable and excellent electric quantity detection device that can respond even if a crack occurs in the quantity V.

An embodiment of the present invention will be described in detail below. 1st
FIG. 4, in which the same parts as in the figure are denoted by the same reference numerals, is a block diagram showing an embodiment of the electric quantity detection device of the present invention, in which _S1 is charged when the output of the level detection circuit 2 is present, and when the output is no. The integral circuit 21 is a level detection circuit that detects when the output of the integral circuit _S1 reaches a predetermined level _VSL .

FIG. 5 is an explanatory diagram of the operation of each part of the electric quantity detection device of FIG. 4, and the left side part A of FIG.
In the case of non-operation when ≦V _L (setting value), the right part B of Fig. 5 shows the case of operation when input electric quantity V≧V _L (setting value), and V _S1 is the output waveform of integrating circuit S ₁ ; V _SL indicates the detection level of the level detection circuit 21, and V ₂₁ indicates the output waveform of the level detection circuit 21, respectively.

The integral constant of the integrating circuit S ₁ is such that when the output of the level detecting circuit 2 continues for 5 ms/time (π/2 in electrical angle based on 50 cycles), the output of the integrating circuit S ₁ becomes the detection level of the level detecting circuit 21. Set to reach V _SL .

Further, the discharging constant of the integrating circuit _S1 is also set to the same value as the charging constant. That is, if no output from the level detection circuit 2 continues for 5 ms, the output from the integrating circuit _S1 falls from _VSL to the threshold value of the integrator.

The operation of the electric quantity detection device of the present invention will be explained below with reference to FIG. 4 and FIGS. 5A and 5B.

If the input electricity quantity V≦V _L and it is inactive, the output _of the integrating circuit _{S 1 will} be The level detection circuit 21 only repeats charging and discharging in a range lower than the detection level of the level detection circuit 21 at the next stage, and no output is generated from the level detection circuit 21, so no output V _p is generated from the output terminal O.

In the case of operation with input electric quantity V≧V _L , as shown in Fig. 5 (b), if the period t ₁₂ in which the input electric quantity V exceeds the detection level V _L of the level detection circuit 2 is 5 ms or more, the integrating circuit is activated.
The output of _S1 is the detection level of the level detection circuit 21.
V _SL rises to a value larger than level detection circuit 2.
1 is detected and made continuous by the next stage timer circuit _T2 , and a continuous output _V0 is obtained at the output terminal C.

Next, with reference to FIG. 6, an explanation will be given of the operation when a crack occurs in the waveform of the input electric quantity when the input electric quantity V≧V _L.

If a crack occurs in the waveform of the input quantity of electricity, a crack will occur in the output waveform _V2 of the level detection circuit 2.
Although it is the same as the conventional device, in the case of the present invention, the output V _S1 of the integrating circuit is discharged only for a minute time width of the crack (for example, 0.1 ms) due to this crack.
Charging is continued again, and the output of the integrating circuit _S1 reaches the detection level of the level detection circuit 21, _VSL , and the level detection circuit 21 responds to provide an output at the output terminal O.

That is, according to the present invention, it is possible to obtain a device with a simple circuit configuration that does not impair its original function even if the input electrical quantity V has waveform distortion or waveform disturbance.

In the above description, the rectifier circuit 1 is a full-wave rectifier circuit, but it can also be a half-wave rectifier circuit depending on the case. In this case, when the operation limit input is reached, the level detection circuit 21 only provides one operation output per cycle, so the recovery time T ₂ of the timer circuit T ₂ is T ₂ = 1 cycle + α (margin). , for example T ₂ =
Set to 1.5 cycles.

Furthermore, in the above description, an embodiment was described in which the detection device outputs an output to the output terminal O if there is an output from the level detection circuit 21, that is, an embodiment that operates when the input electric quantity V is larger than the set value _V4 . If there is an output to the level detection circuit 21, it is also possible to make the output terminal O have no output. In this case, an inverting circuit NOT is connected between the level detection circuit 21 and the timer circuit _T2 .
Insert.

As described above, according to the present invention, a simple circuit configuration in which the conventional device timer circuit T ₁ is replaced with an integrating circuit S ₁ and a level detection circuit 21 causes waveform distortion and waveform disturbance to the input electric quantity V. It is possible to obtain a stable and extremely reliable electrical quantity detection device that does not impair the original function of electrical quantity detection even if this occurs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional electrical quantity detection device, FIGS. 2 and 3 are diagrams explaining the operation of FIG. 1, and FIG. 4 shows an embodiment of the electrical quantity detection device according to the present invention. Block diagram, Figures 5 and 6 are the 4th
Operation explanatory diagram in the figure, I...Input terminal, 1...Full wave rectifier circuit, 2,2
1...Level detection circuit, _T1 ...Operating time timer circuit, _T2 ...Return time timer circuit, _S1 ...
Integrating circuit, V... is input electrical quantity. Also V ₁ …
...Output waveform of full-wave rectifier circuit 1, V ₂ ...Output waveform of level detection circuit 2, VT ₁ ...Timer circuit T ₁
V ₂₁ ...output waveform of the level detection circuit 21, V _p ...output waveform of the output terminal O. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A rectifier circuit that rectifies the input AC quantity of electricity, a first level detection circuit that responds to the instantaneous value output of the rectification circuit, and charges when the first level detection circuit has an output, and charges when there is no output. an integrating circuit that discharges to a threshold value at the cycle of the output of the rectifier circuit that is input to the first level detecting circuit when the temperature increases; a second level detecting circuit that responds to the output of the integrating circuit; An electric quantity detection device equipped with a timer circuit that continuously sends out the output of a level detection circuit.