SU720365A1 - Device for monitoring the presence of voltage of power supply source - Google Patents

Description

I

The invention relates to electrical measurements, control, and signaling and can be used in power supply systems for monitoring the status of power sources.

Devices are known for monitoring the presence of a power supply voltage, comprising a monitored voltage source, relays connected to this source, and signaling nodes D-3.

A disadvantage of such devices is that their low reliability and reliability are due to the constant presence of a voltage relay under current during normal operation of the power supply system.

It is also known a device containing a polarized relay, whose straight and kickdown windings are included in collector circuits of transistors and connected in parallel to a storage capacitor, which is connected via an isolating diode to a power source, resistors and limiting diodes,

connected in parallel to the windings of a polarized relay j.

The drawback of the device is the lack of measures in it to exclude the transfer of contacts of a polarized relay in the course of exposure to vibration loads.

The purpose of the invention is to improve the reliability of the device by eliminating the possibility of spontaneous switching of the contacts of a polarized relay when subjected to vibration loads.

The goal is achieved by adding an additional transistor to the device, whose collector is connected to one of the storage capacitor plates through the first resistor and through the second resistor to the base of the first transistor, the base of the additional transistor and the base of the second transistor, respectively, to the first and fourth resistors power supply, the second pole of which is connected to the emitters of transistors.

3

The second plate of the storage capacitor and the moving contact of the polarized relay, the fixed contacts of which are connected respectively to the base of the first and second transistors,

In the drawing, a schematic image (the proposed device.

The device includes a polarized relay 1, a straight 2 and a breakaway 3 windings of which are included in collector transistors 4 and 5, a storage capacitor 6 connected through an isolation diode 7 to a power supply 8, an additional transistor 9,

the collector of which is connected to one of the plates of the storage capacitor 6 through a resistor 10 and through the resistor 11 to the base of the transistor 4, the resistors 12 and 13 are connected to the first pole of the power supply 8 and the other to the bases of the corresponding transistors 9 and 5 14 and fixed 15, 16 pins of the polar relay 1, limiting diodes 17, 18.

The device works as follows.

When the health is 1NS ;; and 8 power, the storage capacitor 6 is charged

right up to the source voltage

The power supply with the polarity indicated in the drawing, the transistor 9 is opened by the base current from (-5) the source 8 of the lithium through the resistor 12, the transistor 4 is closed, because the power source 8 through the open emitter-collector junction of the transistor 9 and a resistor 11 is applied to the base of transistor 4, the transistor 5 is also closed, because its base-emitter junction is bounded by contacts 14-1 on a polarized relay 1, if the switching-on terminal was on the left fixed contact 16s then the transistor S open first; The base current from the -s- source 8 of the power supply through the resistor 13s breaks off the winding 3 and the moving contact 14 closes with the fixed contact 15, the emitter-base transition of the transistor 5 will be shunted, which will cause the transistor 5 to turn off and de-energize the winding 3,

During normal operation of the power supply 8, the capacitor 6 is charged, the transistor

9 is closed, transistors 4 and 5 are open, windings 2 and 3 are de-energized, moving contact 14 occupies the position indicated by

654

noo on the chisftezhe and corresponds to the presence of the voltage of the power supply source 8.

If the source 8 is faulty, the transistor 9 is closed, the transistor 4 is opened along the circuit: the capacitor 6 positive side, the resistors 1O and 11 the base of the emitter junction of transistor 4, the capacitor 6 negative surface, the coil capacitor 6 is applied to the direct winding 2 of the polarized relay 1, which causes switching of movable contact 14 to stationary 16. Closing contact 14 with contact 16 causes shunting of the base-emitter junction of transistor 4, which closes and de-energizes winding 2 polarized th relay 1, 3 and winding. de-energized because the transistor 5 is closed due to the absence of the voltage of the power supply source 8. The closure of the moving contact 14 with the fixed contact 16 corresponds to the absence of the voltage of the power supply source 8.

If during shock and vibration loads of normal operation of the power source 8, the moving contact 14 of the polarized relay 1 Depart from the fixed contact 15 ,. then transistor 5 will be opened by the base current from the source 8 of the power supply through the resistor 13, winding 3 will receive power, which will trigger relay 1 and return subcontact contact 14 to the right fixed 15, this will close the winding 3 and the contacts of the polarized relay 1 will occupy a position corresponding to the presence of the voltage of the power supply 8. The developed diode 7 eliminates the possibility of discharge of the storage capacitor 6 through the resistance of the power source and the load in the event of a malfunction of the power source. Restrictive diodes 17 and 18 serve as a protection for collector-emitter transitions

transistors 4 and 5 from overvoltages, and also make it possible to eliminate the bounce of the contacts of a polarized relay

The values of the storage capacitor 6 and resistors 10-13 are selected based on the response time of the polarized relay 1,

The advantage of the proposed device is reliability, since it eliminates the possibility of spontaneous switching of the contacts of a polarized relay when subjected to vibration loads.

Claims (1)

Claim A device for monitoring the presence of voltage of a power source, containing a polarized relay, the direct and breakaway windings of which are included in ₅ collector circuits of transistors and are connected in parallel to a storage capacitor, which through decouplings -. The diode is connected to a power source, resistors and restriction days connected in parallel with the polarized relay windings, characterized in that, in order to increase reliability, an additional transistor is introduced into the device, the collector of which 15 is connected through one of the plates of the storage condensate -, pa and through the second resistor with the base of the first transistor, the base of the additional transistor and the base of the second transistor respectively connected through the third and fourth resistors to the first pole of the source power supply, the second pole of which is connected to the emitters of transistors, the second lining of the storage capacitor and with the movable contact of the polarized relay, the fixed contacts of which are connected respectively to the base of the first and second transistors.