SU1273003A3 - Output stage of horizon generator - Google Patents

Abstract

When power is applied to the base of transistor T2 of a deflection circuit (C1, D2, C3, Ly, T2), collector current flowing through transformer winding N2 provides a regenerating base current supply in winding N1 until cut off by trigger transistor T11 when retrace starts. The invention lies in inductor L1 and capacitor C2 which serve to restrict the base current non dissipatively. The circuit is described as inherently short circuit protected, and self oscillatory. <IMAGE>

Description

The invention relates to television technology and can be used as part of scanners of information display devices on cathode ray tubes. The purpose of the invention is to reduce power consumption by reducing active losses in the control circuit. In FIG. 1 is a principle. The electrical circuit of the encoder line scan generator; in fig. 2 - time diagrams1, which explain his work. The output stage of the horizontal scanning generator contains (Fig. 1) the first constant voltage source 1, the second constant voltage source 2, the resistor 3, the first choke 4 the second choke 5, the first transistor 6, the second transistor 7, the first diode 8, the second a diode 9, a first capacitor 10, a second capacitor 11, a deflecting coil 12, a transformer 13 with a primary 14 and a secondary 15 windings, a third capacitor 16 and a third diode 17. The output stage of the horizontal generator operates as follows. When the second source 2 of the direct voltage is turned on by the current flowing through the resistor 3 and the second inductor 5, the second transistor 7 starts to open, causing a current to appear in its collector circuit containing the primary winding 14 of the transformer 13. As a result of the current flow through the winding 14 a voltage appears on the secondary winding 15 of the transformer 13. The indicated voltage, in turn, causes the appearance of current in the circuit the third capacitor 16 - the secondary winding 15 - the first choke 4 - the second choke 5 - the base of the second trans Stora 7 which leads to saturation .tranzistora 7. Thus, flow bootstrapping horizontal output stage of the generator at the moment of power-Viot Consider now the operation: one horizontal scanning stage in a steady state. At the end of the forward sweep stroke at time t, a positive voltage pulse arrives at the bases of the first transistor 6 (Fig. 2a), 55

causing the unlocking of the transistor 7. As a result, the voltage across the collector of the transistor 6 changes its field p1

Claims (1)

the constant voltage and the collector with the cathode of the first diode and with the first output of the resistor, the second terminal (Fig. 25) and under the action of the blocking voltage, the base current of the transistor 7 (Fig. 2 6) decreases at time t the charge resorption process ends at the base of the transistor 7, the latter closes, and in the circuit formed by the capacitors 10 and 11 and the deflecting coil 12, the resonant formation of the reverse stroke begins. At the same time, the reverse pulse (Fig. 22) is generated on the collector of the transistor 7, and the current in the deflecting coil begins to decrease, and then the meznac (Fig. 2a). Approximately in the middle of the reverse stroke (time t ,,), the unlocking pulse at the base of transistor 6 stops, however, transistor 7 continues to remain closed, since the negative voltage that occurs on coil 15 at time is applied to its base through chokes 4 and 5. reverse (Fig.2e). The resulting voltage form at the base of the transistor 7, which is obtained by summing the voltages of the secondary winding 15 and on the capacitor 16 (Fig. 2), is shown in Fig. 2g. At time C4, the resonant formation of the reverse stroke is completed (Fig. 22) and the horizontal sweep begins to flow by unlocking the second diode 9. At the instant of time, the locking voltage at the base of transistor 7 ceases and after some time by time t, - the nominal value of the base current of the transistor is established (FIG. 2b). Further, at the end of the forward stroke of the line scan, the described process is repeated. The source of the enabling current for the transistor 7 is the forward voltage of the second | winding 15 of the transformer 13. Claim of the invention The output stage of the horizontal scanning generator, containing the first transistor, the base of which is the control signal, the emitter connected to the anode of the first diode and with a negative output of the first source