CS241351B3 - Wiring for Transistors Controlled Network Devices for Remote Power Supply Amplifiers - Google Patents

Abstract

The invention relates to the circuit according to Czechoslovak patent No. 1252 258 and solves the problem of securing them against overload while maintaining high control accuracy of the output current. The problem is solved by connecting the measuring resistor (R12) of the output current to the emitter of the control transistor (T3) before the measuring resistor (R4) of another control transistor (T4). The dividing resistors (R10, Rll) of the voltage divider are connected to the emitter of the control transistor (T3) and with their outputs to the negative potential of the output voltage. The points of the voltage divider, formed by the resistors (R4, R12, R10, Rll) are connected to each other by the anodes of two diodes (Dl, D2) and their common connection point is connected to the input (E) of the trigger circuit (Tr).

Description

of amplifiers

The invention relates to the circuit according to the art. No. 1252,258 and solves the problem of securing them against overload while maintaining high control accuracy of the output current.

The problem is solved in that the output current measuring resistor (R12) is connected to the emitter of the control transistor (T3) before the measuring resistor (R4) of the other control transistor (T4). The voltage divider resistors (R10, R11) are connected to the emitter of the control transistor (T3) and their outputs to the negative potential of the output voltage. The points of the voltage divider formed by the resistors (R4, R12, R10, R11) are connected to each other by two diodes (D1, D2) and their common connection point is connected to the input (E) of the trigger circuit (Tr).

241381

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transistor-controlled network apparatus for the power supply of amplifiers in a line in a carrier frequency system having a loss regulator with a control transistor for controlling an astable multivibrator of a pulse frequency regulator. compared with a reference voltage of a reference amplifier whose output voltage is controlled by a control transistor. The invention is dependent on US. No. 152,258 and solves the problem of increasing the control accuracy of the output current.

This circuit is equipped with a foreign-controlled voltage converter with a bridge rectifier and a filter circuit and gives a very constant regulated output current over a wide range of output voltage.

. The downstream voltage converter is connected to a loss regulator for output current control, whose control transistor simultaneously serves to control an analog pulse frequency regulator, which consists of an astable multivibrator downstream of the amplifier connected to it and the following two monostable multivibrator controlled by counter-clockwise .

After each monostable multivibrator, an amplifier stage is connected, each of which controls one transistor of the voltage converter via pulses of constant duration and a pulse frequency that is proportional to the output voltage of the network device.

Such network devices equipped with one or more voltage converters produce relatively high output voltages of up to about 1000 V.

In order to protect the network devices or the amplifier from overload, special measures must be taken to ensure that the network device has been disconnected when the specified output current or output voltage limits are exceeded. Depending on the type of mains device, either relay or trigger circuits are suitable for disconnection. Generally, one measuring resistor for the output current and one measuring resistor for the output voltage are connected to the output of the network devices, at which measurement voltages proportional to the output current and the voltage output are obtained, which disconnects the network device via a trigger circuit.

Experimental connection of such measuring resistors for current and voltage to the output of the network device according to the art. No. 152,258, however, showed that due to the unavoidable erroneous currents of the measuring resistors, the previously achieved high control accuracy of the output current was substantially impaired.

It is an object of the invention to overcome this drawback.

The problem is solved according to the invention in that the output current resistance of the output current is connected to the emitter of the control transistor before the measurement resistance of the next regulating transistor, the first and second dividing resistors of the voltage divider are connected to the emitter of the transistor. .

Between the points of the voltage divider consisting of all four resistors, i.e. the measuring resistor, the output measuring resistor, the first and the second dividing resistor, two diodes are connected to each other, the common switching point of which is connected to the trigger circuit input.

The circuit according to the invention has the advantage that the high control accuracy of the output current is maintained while the mains device is protected against overload.

An example of the wiring according to the invention is shown in the attached drawing, which contains a substantial control part of the wiring of the power supply apparatus according to FIG. No. 152,258, important to illustrate the invention.

The output resistor R12 connected between the emitter of the control transistor T3 and the measuring resistor R4 of the other control transistor T4 serves as the measuring resistor for the output current.

A voltage divider with a first divider resistor R10 and a second divider resistor R11 connected between the emitter of the transistor T3 and the negative potential of the output voltage serves as a measuring cell for the output voltage. Between the points of the voltage divider consisting of all four resistors, i.e. the measuring resistor R4, the output measuring resistor R12, the first resistor R10 and the second resistor R11, two diodes are connected, namely the first diode D1 and the second diode reversed polarity. the wiring is connected to the input E of the trigger circuit Tr. The output A of the trigger circuit Tr is coupled to an astable multivibrator M1 known from the description of Czechoslovak patent No. 152 258.

Trigger circuit Tr acts as a threshold switch. When the overvoltage occurs, the trigger circuit Tr is actuated by means of a second resistor R11 and a first diode D1. When the current limit is exceeded, the trigger circuit Tr is actuated by the output measuring resistor R12 of the second diode D2 and closes the astable multivibrator M1.

Closing the astable multivibrator M1 then disconnects the network device.

Claims (1)

SUBJECT Connections for transistor-controlled network devices for remote supplying of amplifiers in a line in carrier frequency systems, equipped with a loss regulator with a regulating transistor, which also serves to control the -stable multivibrator of the pulse frequency regulator, followed by a measuring circuit 152 258, characterized in that the output current measuring resistor (R12) is connected to the emitter of the regulating transistor (T3) before the measuring resistor (R4) of the invention. the first transistor (T10) and the second voltage divider (R11) of the voltage divider are connected to the emitter of the transistor (T3j) and their outputs to the negative potential of the output voltage and between the points of the voltage divider formed with all four resistors, i.e. the measuring resistor (R4), the output measuring resistor (R12), the first resistor (R10) and the second resistor (R11), are connected by aids the first diode (D1) and the second one a diode (D2), wherein the joint point of both the anodes (D1) and the second diode (D2) is connected to the input (E) of the trigger circuit (Tr).