SU662813A1 - Level relay - Google Patents

Description

(54) LEVEL RELAY

one

The invention relates to the field of instrumentation, in particular, to devices for regulating the level of a liquid and can be used to give a signal for switching the pumping equipment on and off when pumping liquid from tanks, open water bodies, etc. constructions.

Sensors and liquid level detectors are known, which use magnetically controlled contacts which are closed under the action of the permanent magnet 1 field.

These devices cannot be used for level control.

The closest to the technical essence of the invention is a level switch, which contains a sensitive element with a permanent magnet moving with a change of level, a magnetically controlled contact (reed switch) and an excitation winding wound on the reed switch body. Circuit feeds

from the power source 2.

A disadvantage of this device is the uncertainty of the position of the levels at which the release of the reed switch contacts occurs.

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The aim of the invention is to provide a predetermined differential in the actuation and release of the contacts during the forward and reverse stroke.

This is achieved due to the fact that, in the proposed relay, the field winding is connected to the power source in series with the magnetically controlled contact.

The drawing shows the described level switch.

The relay includes a housing 1, a sensing element (membrane) 2, a brush 3, a spring 4, a permanent magnet 5, a magnetically controlled contact (reed switch) 6, an excitation winding 7 and a power supply 8.

The level switch works as follows. When the upper limit level of the liquid is reached, the brush 3 under the action of the membrane 2 brings the permanent magnet 5 to the reed switch 6 so that under the action of the magnetic flux of the permanent magnet the contacts of the reed switch 6 are closed. In this case, the current of the winding 7, connected in series with the contacts of the reed switch 6, creates its own magnetic flux. In this case, the reed switch contacts

will be closed under the action of the total magnetic flux. When the permanent magnet rod moves backward, the closed state of the contacts will be until the effect of the permanent magnet field on the contacts is weakened so that the flow of the winding 7 is not enough to keep them in a closed state. The delay can be adjusted by changing the ampere turns of the winding 7.

Claims (2)

Invention Formula A level switch containing a power supply, a sensing element with a constant t ":": Well "Well" "Well Well" Well 1ZH ";" Yu Well "B A magnet moving with a level change and a magnetically controlled contact (reed switch) with an excitation winding wound on the reed switch housing, characterized in that, in order to provide a predetermined differential in response and release during forward and reverse, the excitation winding is connected to a power source in series with a magnetic contact. Sources of information taken into account in the examination 1 Patent of Great Britain No. 1273543, cl. G 1 H, 1972. 2. USSR author's certificate No. 510646, cl. G 01 F 23/12, 1974.