Bistable reed switch MKE‑50203 RZMKP


Bistabil'nyj gerkon MKE-50203 RZMKP

As you know, any mechanical contacts are subject to wear. To reduce this destructive factor, in the middle of the last century, switching magnetically controlled devices were developed, the contact group of which was placed in a vacuum flask. Such devices are called "reed switch", which is an abbreviation for "sealed contact".

Switching devices of this class are usually divided (depending on the device of the contact group) into the following types:

  • Elements with normally open contacts;
  • Elements with normally closed contacts;
  • Elements with switching contacts.

It would seem that what can be added to this? It turned out that there is something to add…

Electromagnetic relays include a special class of devices called "bistable" relays. Unlike conventional relays, the state of the contacts of which depends on the presence of a control voltage on the coil, bistable relays "remember" the state of their contacts after the control voltage is removed. To return the contact group to its original position, it is necessary to change the polarity of the control voltage, or (depending on the design of the relay) apply an additional coil.

The bistable reed switch MKE-50203 works in a similar way. The principle of operation of a bistable reed switch is based on the fact that a reed switch with normally open contacts, under a certain influence of an embedded magnet, can be in two states - normally open or normally closed. The reed switch can be in these states for any length of time. Its switching occurs when exposed to an external, strictly defined in relation to the internal, magnetic field. The principle of operation of the sensor based on a bistable reed switch:

Princip raboty datchika na osnove bistabil'nogo gerkona

When moving to the left, the reed switch contacts open, and remain open when the external magnet stops acting. When moving to the right, the contacts close, and remain closed when the external magnet stops acting. Switching contacts takes place even without connecting power to the reed switch.

The second option is to use the sensor on a bistable reed switch:

Vtoroj variant ispol'zovaniya datchika na bistabil'nom gerkone

When exposed to the "N" pole, the reed switch contacts close, and retain their state when the external magnetic field stops acting. When exposed to the "S" pole, the contacts open, and remain open when the external magnetic field stops acting. It should be borne in mind that when using a bistable reed switch in this way, two magnets must be used.

The most obvious is the use of a bistable reed switch as a liquid level sensor.

Ispol'zovanie bistabil'nogo gerkona v kachestve datchika urovnya zhidkosti

The principle of operation of such a device is quite simple. The float with a magnet inside moves freely along a vertical pipe (guide) in accordance with the liquid level. As soon as the liquid rises to the intended point, the magnetic field of the float is affected by the reed switch installed at the appropriate level. Using two bistable reed switches installed at different levels, it is possible to obtain the simplest device for automatic control of the liquid level. When the minimum level is reached, for example, the liquid pumping pump turns on. When the upper level is reached, the pump turns off. And all this without the use of expensive equipment. Using several bistable reed switches with LEDs displaying the contact status, a discrete liquid level indicator is obtained. The discreteness of such a device is determined by the distance between adjacent reed switches.

Overall dimensions of the reed switch MKE-50203

Gabaritnye razmery gerkona MKE-50203

Main technical parameters

  • Current switched/transmitted: 2/2A;
  • Switching voltage: 250V:
  • Switching power: 150W, VA;
  • Climatic version: UHL 2.1;
  • Relative humidity: 98% at 35°;
  • Operating temperature range: -60...+70°C.