SU1645843A1 - Level signaling apparatus - Google Patents

Abstract

The invention relates to a measurement technique, in particular to devices for determining the level of bulk materials. The purpose of the invention is to increase the reliability of the device. When the bulk material appears and contacts with the membrane 3, the oscillation amplitude in the electromechanical oscillatory system decreases until the oscillations break down, the variable component at the output of amplifier 7 disappears and a signal is opened at the output of discriminator 9, which opens the signal device 11 a control signal is received and it is put into operation, thereby ensuring that the recording device 8 provides information on the achievement of a certain level by the bulk material. 3 il. SL S O CL 00 4 00

Description

The invention relates to a measurement technique, in particular, to devices for determining the level of bulk materials of different dispersion, such as grain, flour, and so on.

The purpose of the invention is to increase the reliability of the device.

Figure 1 shows schematically the structure of the device proposed; figure 2 - section aa in figure 1; Fig. 3 - level indicator, structural diagram.

The level indicator consists of a cylindrical body 1, a flange 2, a flat steel membrane 3, sandwiched between the body 1 and the flange 2. On the back wall of the body 1 two electromagnet 4 coils 4 and the sensor coil 5 of the speed of movement of the membrane 3 are cross-shaped. Inside the coils there are cores 6 of ferromagnetic material. There is an air gap between the ends of the cores 6 and the membrane 3. The distance between the axes of the coils of the sensor 5 and the axes of the coils of the electromagnet 4 is the same.

The output of the sensor 5 is connected to the bypass of the amplifier 7 with adjustable phase response. The output of amplifier 7 is connected to an electromagnet 4 and a recording device 8 containing an amplitude discriminator 9, a key element 10 and a signal device 11.

The detector works as follows,

When the power is turned on, the output of the amplifier 7 operating in the active mode of class L appears to be a voltage equal to half the supply voltage. Under the action of this voltage, an elec- tic current flows through the electromagnet L. The magnetic field created by the electromagnet 4 acts on the membrane 3, causing it to oscillate in the absence of a controlled bulk material. Moving, the membrane 3 changes the magnetic flux passing through the coils of the sensor. The diaphragm moves quickly. The amplitude of the signal from sensor 5 of the speed of movement of the membrane 3 is proportional to the speed of movement of meme & wounds 3

By the amplifier 7, the signal from the sensor 5 of the speed of movement of the membrane 3 is amplified in amplitude and stays in phase until it coincides with the phase of the input signal of the sensor 5. The change in voltage at the output of the amplifier 7 causes the current flowing through the electromagnet 4 to change and change

magnetic field created by him. In this way, a closed loop of positive electromechanical feedback is formed in the electromechanical

an oscillatory system comprising an electromagnet 4. a membrane 3, a sensor 5 of the speed of movement of the membrane and an amplifier 7 made with an adjustable phase characteristic in which the membrane 3

oscillates at the frequency of its own mechanical resonance. In this case, the output of the amplifier 7 produces an electrical signal with a variable component of the oscillation determined by the oscillation frequency

membrane 3.

An amplitude discriminator 9 is connected to the output of amplifier 7, by means of which the variable component is controlled in such a way that if there is a variable component at the input of amplitude discriminator 9, there is no signal at its output. For this, the output of the amplitude discriminator 9 includes a key element 10 loaded onto the signal device 11, for which a light bulb or a bell can be used. In the absence of controlled material, the key element 10 is closed and the signal device 11 does not work.

With the appearance of bulk material and its contact with membrane 3 due to the damping effect of the material, the oscillation amplitude in the electromechanical oscillatory system decreases to

before the oscillations break down, the variable component at the output of the amplifier 7 disappears and the output of the discriminator 9 generates a signal that opens the key element 10. At the same time, the control signal 11 receives a control signal and it goes into operation, thereby providing the recording device 8 with information about achievement of bulk material of a certain level.

Formula of invention

A level detector containing an electromechanical oscillatory system with windings connected to the feedback circuit of a measuring device,

made in the form of an amplifier, a recording device, characterized in that, in order to increase reliability, an amplitude discriminator connected to the output of an amplifier made with an adjustable phase characteristic is included at the input of the recording device.

Aa

2

1

Claims (1)

Claim The level switch containing an electromechanical oscillatory system with windings included in the feedback circuit of a measuring device made in the form of an amplifier, a recording device, characterized in that what. in order to increase reliability, an amplitude discriminator connected to the output of an amplifier made with an adjustable phase characteristic is included at the input of the recording device. A Figure 1 Aa FIG. 2