RU1788595C - Output stage of horizontal scanning oscillator - Google Patents

Abstract

The invention relates to television technology and can be applied to devices with a raster scan method, specifically for reproducing alphanumeric and graphic information. The purpose of the invention is to reduce power consumption. The inventive output stage of the horizontal generator contains: a first resistor 1, an output transistor 2, a power choke 3, a first diode 4, a first capacitor 5. a second capacitor 6, a biasing coil 7, a second resistor 8, a second transistor 9, a first transistor 10 second diode 11, transformer 12, fifth diode 13, fourth resistor 14, fourth capacitor 15, third resistor 16. fourth transistor 17. sixth diode 18, third diode 19, third capacitor 20, fourth diode 21. 1 ill.

Description

The invention relates to television technology and can be used in horizontal scanning units.

The output stage of the horizontal scanning generator (GSR) is known, comprising a matching transformer, an output transistor, a power choke, a damping diode, a back-up capacitor, an S-correction isolating capacitor, an off-coil.

A drawback of the considered circuit of the GSR output stage is the significant power loss in the collector circuit of the output transistor due to the longer turn-off time of the transistor, consisting of the resorption time and the decay time of the collector current. The consequence of this is the low speed of the circuit, which limits the possibility of increasing the horizontal frequency of horizontal scanning, which is necessary to increase the resolution of the device in which this circuit of the output stage of the GSR is applied. ; : -: V.-.

The closest technical solution to the proposed TQP output stage circuit is an output stage circuit of a pulse-coupled GSR comprising an output transistor, a power choke, a damping diode, a reverse capacitor; isolation capacitor, bias coil, key transistor control transistor, electronic line size controller, diode. . .

The loss of power dissipated at the output transistor for a given technical solution, and hence the power consumption, remains significant. It is possible to increase the efficiency of the circuit of the output stage of the GSR if the loss of power for switching due to the significant time of locking the output transistor is reduced. Reducing the locking time creates opportunities for increasing the horizontal scanning frequency and, consequently, increasing the resolution of the device in which the GSR is applied.

Note other disadvantages of the prototype circuit. -In the prototype circuit, when reducing power losses when adjusting the row size, the conditions for compensating power losses in the GSR output stage worsen, the conditions for triggering the GSR output stage deteriorate due to the fact that the isolation capacitor is not charged continuously from the TCP source during the transient on-time voltage, but pulse.

The aim of the proposed technical solution is to reduce energy consumption.

The drawing shows a diagram of the proposed technical solution.

The output stage of the GSR contains: the first resistor 1; output transistor 2; power choke; first diode 4; the first capacitor 5; second capacitor 6; tilting coil 7; second resistor 8; second transistor 9; first transistor 10; second diode 11; transformer (inductive energy storage, INE) 12; fifth diode 13; fourth resistor, 14; fourth 5 capacitor 15; third resistor 16; fourth transistor 17; sixth diode 18; third diode 19; third capacitor 20; fourth diode 21. ;; -. ;; -;

The device operates as follows.

. The output transistor 2 is controlled by voltage pulses Pu2. coming to his base. For the formation of a sawtooth current flowing through

5, the deflection coil 7, the transistor 2, under the influence of control pulses, is unlocked for the duration of the forward stroke and is locked for the time of the reverse motion. The source of energy causing the current to appear in the deflecting coil 7 is a separation capacitor 6. This capacitor is charged during the transient switching on of the GSR output stage not directly from the constant source

5 by voltages Ei, and by voltage pulses which are generated on the collector of the key transistor 10, rectangular pulses Uyi are used to control the transistor 10. having a lowercase frequency

0 sweeps and supplied to the base of the input transistor 9. By adjusting the duration of the control mm pulses Uyi, you can change the duty cycle of the supply voltage pulses on the collector 10 and, therefore, the voltage value on the isolation capacitor 6, which leads to a change in the current amplitude in the deflecting coils 7. Thus, on the key transistor 10, an electronic line size regulator (RPC) is made, which makes it possible to change the amplitude of the deviation current with minimal power loss on the control element. Diode 4 is a damping and provides the formation of

5 of the deflection current during the first half of the forward sweep. The capacitor 5, together with the inductance of the deflection coils 7, forms an oscillating circuit during the reverse sweep. Replenishment of losses in the output stage of the GSR is carried out as in the prototype circuit, during the reverse sweep by recharging the isolation capacitor 6 due to the energy stored in the power choke 3. In this case, the diode 11 ensures the passage of the indicated charging current of the capacitor 6. Compensation for power losses is carried out by means of the energy stored in the power reactor 3 not only due to the current consumed from the voltage source Ei, but also due to the current discharge of the storage capacitor 20. For this purpose, There is an inductive energy storage device (INE) made in the form of a transformer 12, the primary winding of which is included in the emitter circuit of the key regulator of row size 10. During the open state of the transistor 10 in the primary winding AB, the INE 12 is stored with energy. When the key storage transistor 10 is locked, energy is transformed into the secondary circuits VG and DE and used to charge the storage capacitor 20 and the charge of the capacitor 15, which controls the unlocking of the additional key transistor 17. When the transistors 10 and 2 are unlocked through the power choke 3 along with the current consumed from the voltage source Ei, the discharge current of the storage capacitor 20. These currents provide the energy stored in the inductor 3 and necessary to compensate for the power loss in the output stage of the mains . When the transistor 10 is locked, the storage capacitor 20 begins to charge due to the energy stored in the primary winding of the AB transformer 12. In this case, the current circuit of the throttle 3, due to the presence of the diode 11, is not interrupted, and during the return stroke, the throttle current of the supply 3, due to the stored during a direct stroke of energy, the isolation capacitor 6 recharges, which compensates for the power loss in the output stage of the GSR. The diode 19 prevents the discharge of the storage capacitor 20 to the secondary winding DE, the diode 21 eliminates the charge of the capacitor 20 from the voltage source EL. Thus, in the proposed circuit, the conditions for compensating power losses during the reverse sweep are improved by increasing the stored energy by the power choke during the forward stroke, which is due to the flow of the charging current of the storage capacitor 20, and not due to an increase in the current consumed by or the voltage source Ei. or increase the inductance of the power throttle 3. This eliminates the need to increase the stock during direct

the energy flow in the power choke 3 due to an increase in the current consumed from the voltage source Ei or due to an increase in the inductance of the power choke. When 5 of the key transistor 10 is locked on the second secondary winding of the VT transformer 12 (INE), a voltage pulse appears; on which the charge of the capacitor 15 of the integrating RC circuit 14, 15 is charged. When the capacitor 15 charges 0 before the unlocking voltage of the additional key transistor 17 is turned on, the latter connects the voltage source Ea to the collector-base junction of the output transistor 2. Locking current pulse

5 passing through said junction reduces the saturation of the output transistor 2 before turning it off. As a result, the absorption time of the excess charge and the decay time of the collector current and, consequently, the power loss is not switched, are reduced. Depending on the limits of regulation of the amplitude of the deflection current, the time constant of the RC circuit 14, 15 is selected.

5 t8 disconnects the circuit, which forces the locking of the output transistor 2, when a pulse appears, the voltage of the reverse motion of the sweep. Thus, the feature of the proposed circuit output stage

0 GSR consists in the fact that it transfers the energy stored by the inductive energy storage to the circuit of the formation of the deflecting current: Since the energy consumed by the circuit from

5 of the power supply is determined by the losses in the circuit, then compensation for losses due to the energy stored in the INE leads to a decrease in the power consumption of the output stage of the GSR.

Claims (1)

0- Claims The output stage of the horizontal generator containing the first key transistor, the base of which is connected to the first output of the first resistor, the second output of which is connected to the positive the pole of the first voltage source and the first output of the second resistor, the second - the output of which is connected to the collector the second transistor, the base of which is connected to the input of the first control signal, and the emitter is connected to the housing, the third transistor, the base of which is connected to  the input of the second control signal, and the collector is connected to the cathode of the first diode, the first terminal of the first capacitor, the first terminal of the second capacitor, the first terminal of the power supply circuit, the second terminal of which is connected to the collector of the first transistor and the cathode of the second diode, the anode of which is connected to the housing, to which is connected to the emitter of the third transistor, the anode of the first diode, the second terminal of the first capacitor, the first end of the bias coil, the second end of which is connected to the second terminal of the second capacitor, characterized in that, in order to reduce power consumption, a transformer is inserted into it, the first terminal of the primary the winding of which is connected to the positive pole of the first voltage source, and the second terminal of the primary winding is connected to the emitter of the first transistor, the first terminal of the third capacitor and the first end of the the second winding, the second end of which is connected to the cathode of the third diode, the anode of which is connected to the second terminal of the third capacitor and the cathode of the fourth diode, the anode of which is connected to the housing, the fifth diode, the anode of which is connected to the first end of the second secondary winding, and the cathode is connected to the first terminal of the third resistor and the first end of the fourth capacitor, the fourth resistor, the first terminal of which is connected to the second end of the second secondary winding, and the second terminal is connected to the second end of the fourth capacitor, the emitter is even the fourth transistor and the anode of the sixth diode, the cathode of which is connected to the collector of the third transistor, the fourth transistor, the base of which is connected to the second terminal of the third resistor, and the collector with a positive pole of the second voltage source, the negative pole of which is connected to the base of the third transistor.