JPH062177U - Vibration measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a vibration measuring device in which the output does not rise as directed even when the -15V of the ± 15V power supply in the device is down. [Structure] An isolation amplifier 8 driven by an AC / DC power supply of a conversion circuit 4 is provided between a detection circuit 4 and a comparator circuit.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vibration measuring device that measures vibration of a rotating body such as a turbine generator and is used as an instrument for monitoring a turbine.

[0002]

[Prior art]

FIG. 5 is a block diagram showing a conventional vibration measuring device. In Fig, 1A is the main body of the vibration converter, 2 conversion circuit for converting a displacement proportional signal receives the detection signal V _in from the vibration detector 1, 3 is generated by the earthquake is connected to the output side of the converter circuit 2 A low-cut filter for removing the vibration frequency, 4 is a detection circuit, 5 is a smoothing circuit which is connected to the output side of the detection circuit 4 and outputs a measurement output V _D , 6 is a power supply of ± 15 V or the like for the circuits 2-5. An AC / DC power source to be supplied, and 7 is a DC cut capacitor. 2A is the alarm device body, 11 and 12 are comparators, 13 and 14 are auxiliary relays, 15 and 16 are auxiliary relay contacts, 17 is AC / DC power supply that supplies ± 15V power to the comparator Is.

Next, in the circuit of FIG. 5, the operation when one of the ± 15 V power source outputs of the AC / DC power source 6 of the vibration converter 1A is down will be described. The conversion circuit 2, the low-cut filter 3, and the detection circuit 4 use analog operational amplifiers (operational amplifiers). This operational amplifier is driven by ± 15V power supply, and the logical output is about -13V to + 13V. When + 15V of the AC / DC power supply 6 is lowered to 0V, the operational amplifier becomes a single power supply of -15V, and its logical output is about -13V to -2V. Next, when -15V is lowered to 0V, the operational amplifier becomes a single power source of + 15V, and its logical output is about 2V to 13V. This means that if the output signal of the vibration detector 1 is zero, the output V _{D of the} vibration converter is 0 V, but if the -15 V power source fails and becomes 0 V, V _D outputs 2 V or more. It will be a thing. FIG. 6 is a time chart showing the relationship between the output V _D and when the ± 15 V power supply is down.

[0004]

[Problems to be solved by the device]

Since the conventional vibration transducer device is constructed as described above, AC / DC power supply - when 15V is down to 0V, the vibration transducer output V _D is the output rises. Due to this, there were problems such as erroneous output of an excessive vibration trip from the alarm device 2A.

The present invention has been made to solve the above problems, and the output of the vibration conversion device output V _D rises even if -15V of the AC / DC power supply of the vibration conversion device is reduced to 0V. The purpose of the present invention is to obtain a vibration measuring device capable of preventing the vibration.

[0006]

[Means for Solving the Problems]

 In the vibration measuring device according to the present invention, an insulating amplifier is provided at the output of the smoothing circuit or the detection circuit in the vibration converting device, and it is considered that the power of this insulating amplifier is supplied from the -15V line.

[0007]

[Action]

 In the vibration measuring device according to the present invention, when the -15V power supply goes down to 0V, the added insulation amplifier is driven by the -15V power supply, so the insulation amplifier power supply disappears, so the vibration converter output (isolation amplifier output) Is 0V.

[0008]

【Example】

 Example 1. A first embodiment of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a vibration measuring apparatus according to a first embodiment of the present invention. In the figure, the same parts as those already described refer to the same parts, and a description thereof will be omitted. In FIG. 1, 1M is the main body of the vibration conversion device according to the present embodiment, and the difference between the device 1M of the present embodiment and the conventional device 1A is that an isolation amplifier 8 is added to the output of the smoothing circuit 5, and the isolation amplifier 8 The only power source is that it is supplied from -15V.

Next, the operation will be described. The basic operation is the same as that of the conventional vibration converting apparatus 1A, and therefore its explanation is omitted. By adding the isolation amplifier 8 in the present invention, when the -15V power source becomes 0V, the isolation amplifier power source also becomes 0V, so that the amplification function of the isolation amplifier is stopped. Therefore, the output V _D of the vibration conversion device 1M becomes 0 V, and the output increase of the vibration conversion device 1M can be reliably prevented. FIG. 2 is a time chart showing the relationship between the output V _D when the ± 15 V power supply is down.

Example 2. Although in the first embodiment the isolation amplifier 8 is connected to the output of the smoothing circuit 5, the isolation amplifier 8 may be arranged between the detection circuit 4 and the smoothing circuit 5, and in this case as well. The same effect as that of the above embodiment is obtained. (The isolation amplifier in FIG. 3 is denoted by 8M.) FIG. 3 is a block diagram according to the second embodiment, and FIG. 4 is a time chart.

[0011]

[Effect of device]

 As described above, according to the present invention, the smoothing circuit output in the vibration conversion device is provided with the isolation amplifier driven by the -15V power supply, so that the output of the vibration conversion device is reliably prevented from rising when the -15V power supply is down. A vibrating measuring device can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a vibration measuring device according to a first embodiment of the present invention.

FIG. 2 is a time chart of the output of the vibration converter when the power supply of FIG. 1 is down.

FIG. 3 is a block diagram showing a vibration measuring device according to a second embodiment of the present invention.

FIG. 4 is a time chart of the output of the vibration conversion device when the power supply of FIG. 2 is down.

FIG. 5 is a block diagram showing a conventional vibration measuring device.

FIG. 6 is a time chart of the output of the vibration conversion device when the power supply of FIG. 5 is down.

[Explanation of symbols]

 1 Vibration detector 7 DC cut capacitor 8 Insulation amplifier 13 Auxiliary relay 14 Auxiliary relay 15 Auxiliary relay contact 16 Auxiliary relay contact

Claims (1)

[Scope of utility model registration request] 1. A conversion circuit for converting a detection signal for vibration of a rotating body input via a vibration detector into a displacement proportional signal, and an analog comparator circuit for receiving an output signal of the conversion circuit and outputting an alarm. The vibration measuring apparatus, wherein the vibration measuring apparatus comprises an insulating amplifier driven by an AC / DC power supply of the converting circuit between the converting circuit and the comparator circuit.