DEVICE FOR PROTECTION OF INSTRUMENTS AGAINST OVERLOADS Russian patent published in 1994 - IPC

FIELD: radio engineering. SUBSTANCE: device for protection of instruments against overload has spark protection unit including stabilizer diode 2, resistors 3, 4 connected in series, communication line 6 coupled to terminal 5, diode 7 and resistor 8 linked in series with communication line, point of their connection is coupled to neutral wire via diode 9. Stabilizer diode 2 is shunted by resistor 11. Instrument 13 is connected to terminal 12. Instrument converter is placed into load of power supply source 30. One of its circuit includes resistors 16, 17, 18, capacitor 19, transistor 20 and 21, feedback and intercommunication resistor 22 and forms amplifier of pickup signal. Second circuit includes voltage stabilizer built on field-effect transistor 24, transistor 25 which connection point is coupled to source of reference voltage via resistor 26. Source includes stabilizer diode 27 connected to base of transistor 25 and resistor 28. EFFECT: improved operational efficiency and reliability. 1 dwg