SU1238188A2 - Device for overload protection power source - Google Patents

Abstract

This invention relates to a device for protecting a power source against overload. The goal is to enhance functionality by providing protection against exceeding the output voltage of the source. With an increase in the load current, the voltage on the sensor current r1 increases. As soon as the voltage on R1 surpasses. the voltage of the DZ support, the transistors (T) 1 and 2 are closed. The capacitor C1 is charged through the resistor R5 to the voltage of the DZ support. The TOR is released and the relay P causes a signal to disconnect the source from the mains. During transient overloads, the power supply is not disconnected. With a voltage and power protection circuit (the source protection circuit does not work) Zener diode D4 is punctured, while T4 and T5 open, close T1 and T2. When T1 and T2 are closed, signals are output to the current limiting devices. The voltage reduction at the power supply is complete before the current limiting is used ---. tochnik. Decreasing the source voltage to the original level causes T4, T5 to turn off, T1, T2 to turn on and to remove signals from the current and voltage limiting device. 1 il. Q W n ffffl. about Lkari from 00 00 00. ..ife / rv

Description

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The invention relates to electronics, in particular to a source of protection of a source of electrical power in an overload supply, is in addition to the invention according to the author. (R 826495.

The aim of the invention is to enhance the functionality of the protection device by providing protection against the output voltage of the source voltage tree. .

In the drawing, the electrical circuit diagram of the device for the device is designed in principle. protection.

Marked: + gtr i terminals for connecting the power source of the device to the device; ..T. - terminals for connecting the load power source.

The device contains a current sensor R1, connected to the negative and positive poles of the power supply of the load, -a midpoint with the anodes of the Zener diodes. Д1 and Ц2, the supporting element ДЗ, connected through the resistor R2 to the positive pole of the protection device, the threshold amplifier containing the transistor T1, the base which through the resistor R3 is connected to the cathode of the Zener diode D: 1, its emitter is connected; to the negative pole of the protection device and the cathode of the Zener diode D2, -a the collector is connected to the current-limiting device and through the resistor R4- with positive. protection pole, shunt transistor T2, emitter and. the collector, which is connected to the positive and the negative, is the terminal of the condiver. and C1 is the time of the driving circuit.

The device also contains a terminal amplifier on the transistor TZ., The base of which is connected to the emitter of the shunt transistor and through a variable resistor R5

 The circuit is connected to the positive pole of the protective device, which is connected via a winding of relay P to the collector and through a resistor R6 to the emitter of the terminal amplifier TK and to the cathode of the source of the reference voltage. DZ, the anode of which is connected to the positive pole of the load power source, the collector of the shunting transistor T2 and the emitter of the reference amplifier T1, the collector of which is connected via a resistor R7 to the base of the transistor T2. In the device

2381882

 There is also a threshold protection element D4 from overvoltage, the anode of which is connected to the base of the transistor T4 amplifier, and through the resistor R8 to its emitter, and the cathode is connected through the resistor R9 to the positive pole of the load supply source, the transistor T4 providing: preliminary Amplifier, emitter 10 connected to the negative pole of the power source of the load and through a resistor 8 to its base, a transistor T5 of the terminal amplifier, the base of which is connected through a resistor R10 to tS with a collector of transistor T4, and the emitter and collector op connected to the cathodes: zener diodes D1 and D2, respectively.

The device works as follows. .

With increasing load current,

flowing in the direction indicated by the arrow, the voltage on the current sensor R1 rises. In this case, as soon as the voltage across R1 exceeds the voltage of the support, the transistor T1 closes, which causes the transistor T2 to close. Capacitor C1, the time of the master circuit will begin to charge through resistor R5 to the voltage of the reference source DZ. In this case, the transistor TZ of the terminal amplifier is opened and the relay P closes its contacts, giving a signal to disconnect the source from the mains.

If the AVARSE signal exceeds the time constant of the time-driving circuit in time, then the power supply source is disconnected. In case of transient overloads, the power supply is not disconnected.

If the voltage of the power source is higher than the allowable one, when the voltage increase is less than 10% of the initial (voltage protection) or greater than or equal to 10% of the initial voltage (power protection), at a load current not exceeding the overload of the power source ( the power supply fails to break), the Zener diode D4 is punched, the transistors T4 and T5 of the amplifier are opened, which causes the transistors T1 and T2 to close, and then the device works similarly to protecting the power supply from overloads.

When shading transistor T1 simultaneously with the locking of the transistor

T2 gives signals to current limiting devices (with an overload protection circuit) and reducing the voltage of the power source to the initial one (when the circuit is set for voltage and power), and the voltage at the power source is reduced by the device before the start of the limitation. power supply current. Power supply voltage before initial voltage reduction device voltage: leads to transistors T4 and T5 turned off, T1 and T2 transistors turned on and the signals from the current limiting devices and the power supply voltage were turned on.

F o. r mula a isobre et e and

Device to protect the power source from overload, according to author. W 826495, characterized in that, in order to expand functionality by providing editor L. Povkhan Order 3301/55

Compiled by O. Mescher Kova

Tehred O.Gortvai Proofreader m.Samborsk

Circulation 612. Subscription

VNISHI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company and tye, Uzhgorod, Projecto st., 4

protection against n: revs of the output voltage of the source, an additional Zener diode, the first, second and third resistors, a pn-type transistor and a pnp-type transistor, and the emitter of the p-type transistor pn-type is connected to the cathode of the support element, and the base is connected via a first additional resistor to a pnp-type trasistor collector, the base of which is connected through a series-connected additional zener diode and a second additional resistor to be connected to the positive power supply pole connected to the negative pole of the protection device and the collector of the pnp type transistor, while the emitter; pnp type transistor is designed to be connected to the negative pole of the power supply of the load and through a third additional resistor connected to it base.

Claims (1)

Claim Device for protecting power supply 20 from overload, according to ed. No. 826495, characterized in that, in order to expand the functionality by providing protection against exceeding the output voltage of the source, an additional zener diode, first, second and third resistors, a ~ p-p-p-type transistor and a p- transistor are introduced into it p-type, and the emitter of the pnp-type transistor is connected to the cathode of the reference element, and the base is connected through the first additional resistor to the collector of the p-p-type transistor, the base of which is connected through an additional zener diode and a second additional resistor The torus is designed to connect to the positive pole of the load power source and is connected to the negative pole of the protection device and. transistor collector p-n-p type, wherein the emitter / npn-type transistor for ² cheniya connected to the negative pole of the power source and the load through a third further resistor connected to its base.