SU849177A1 - Device for voltage stabilizer protection - Google Patents

Description

one

The invention relates to radio electronics and can be used by the power supply system of automation devices, computer technology and communications equipment. .

Protection devices for voltage regulators are known that provide for the deviation of the stabilizer or power supply circuits of the equipment while reducing the output voltage to a predetermined threshold level D.

The closest in technical essence to the proposed is. power supply with a signaling of the minimum allowable voltage, containing a control transistor, the emitter of which is connected to the minus bus and one of the terminals of a resistive nicking divider, whose midpoint is connected to the base of the specified transistor, the collector of which is connected to one of the terminals of the collector resistor, thyristor cathode which is connected to the negative.

bus, and the anode to one of the terminals of the relay winding. Device protection ensures that the battery is disconnected from the load by decreasing the voltage at its output to a given threshold r2j

However, in practice, the problem often arises of disconnecting a power source operating from an AC network (for example, voltage stabilizer 10) when the output voltage level drops to a certain threshold. A disadvantage of the known power source is that when the network is turned on, a current pulse passes, the relay

Claims (2)

15 triggers and turns off the network, i.e. passes the false defense of protection. In addition, when operating the device in the field of small input voltages (in the order of a few volts), significant difficulties arise with the choice of relay and thyristor types, for which the operating voltage is usually higher than six volts. Operating the relay and thyristor 3 in non-predetermined modes reduces the reliability of the device. The purpose of the invention is to increase the reliability of the voltage stabilizer protection device. The goal is achieved by introducing an additional voltage source, a storage capacitor and a limiting resistor into the device, with the capacitor being connected to the emitter of the control transistor one end and the other the output to its collector and through the limiting resistor to the control electrode of the thyristor; in addition, another output of the collector resistor is connected to the positive output of the additional source Neither to the other side of the relay winding, the negative terminal of the additional voltage source is connected to the negative bus, and the other terminal of the resistive voltage divider is connected to the positive bus ,. The drawing shows a circuit diagram of the proposed device. The device contains an auxiliary voltage source 1, busbars 2 and 3, a control transistor 4 with a collector resistor 5, a thyristor 6 with a limiting resistor 7, a winding 8 relays, and a storage capacitor. 9 and the resistive divider is 10 voltages. The device works as follows. When the output voltage level drops to a certain threshold, the control transistor 4 closes, and a positive voltage is applied to the control electrode of the thyristor 6 through the limiting resistor 7, which sets the operating current of the control electrode of the thyristor. The thyristor 6 opens, a current begins to flow in the relay circuit, relay 8 operates and shuts down either the stabilizer supply circuit or the load circuit. The protection threshold is determined by the ratio of the shoulders of the resistive voltage divider 10. When the stabilizer is turned on, the voltage on the output tires 2 and 3 at capacitive load increases exponentially. In this case, the control transistor 4 is bridged — by a capacitor 9, which is charged from the auxiliary voltage source 1 through the collector resistor 5. The charging time T is determined by the values of the collector resistor 5 and the storage capacitor 9 and is chosen so that the rise time of the output voltage When the storage capacitor 9 is not charged, the control transistor 4 is not closed, and the control signal is not sent to the control electrode of the thyristor 6. After the charge of storage capacitor 9 is completed, the device is ready for operation and, when the voltage on tires 2 and 3 is reduced to a threshold level, ensures the disconnection of the power supply to the stabilizer or load. Claim device A voltage regulator protection device containing a control transistor, the emitter of which is connected to the minus bus and one of the terminals of a resistive voltage divider, the midpoint of which is connected to the base of the specified transistor, the collector of which is connected to one of the terminals of the collector resistor, the thyristor, the cathode which is connected to the negative busbar, and the anode to one of the terminals of the relay winding, characterized in that, in order to increase reliability, an additional voltage source has been introduced into it,. A capacitor capacitor and a limiting resistor, and the capacitor is connected to the emitter of the control transistor with one output and the other output to its collector and through the limiting resistor to the control electrode of the thyristor, in addition, another output of the collector resistor sub-. The key is connected to the positive terminal of the additional voltage source and to the other terminal of the relay coil, the negative terminal of the additional voltage source is connected to the negative bus, and the other terminal of the resistive voltage divider is connected to the positive terminal. Sources of information taken into account in the examination of 1, USSR Copyright Certificate No. 460541, cl. G 05 F 1/58, 1975. 2. USSR author's certificate number 355608, cl. G 05 F 1/58, 1972.