JPS59143477A - Fly-back transformer - Google Patents

Abstract

PURPOSE:To reduce the number of winding times of a winding and to reduce the insulation of the winding and the reverse voltage resistance of rectifier elements by providing inductance elements connected with the rectifier elements in series between the terminals of the primary and/or tertiary windings in a fly-back transformer which take out a positive polarity pulses. CONSTITUTION:A power source is supplied to the terminal 2 of the primary windings N11, N12 in the fly-back transformer 1 and voltage rectified by a diode D2 is smoothed by a capacitor C1 and supplied from a terminal 7 to a video output circuit. The voltage of the secondary windings N21-N24 is rectified and supplied to a CRT and the voltage of the tertiary windings N31-N33 is rectified by diodes D1, D6, smoothed by capacitors C2, C3 and supplied from terminals 5, 6, 13 to circuits such as the CRT and a tuner. The indactance elements L1, L2 connected with the diodes D2, D1 in series are provided between the terminals of the primary windings N11, N12 and/or the tertiary winding N33 in the transformer 1 which takes out positive polarity pulses and the smoothing capacitors C1, C3 and the values of the indactances L1, L2 are set up so that the high voltage of the windings N21-N24 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flyback transformer, in which an inductance element is provided in a rectifying element stopper row between a 1 m element and a smoothing element to extract a pulse voltage of positive polarity. It is an object of the present invention to provide a flyback transformer with improved rate and efficiency.

In recent pre-vision receivers, the flyback transformer is used to supply the anode voltage to the picture tube.
A small signal circuit such as a tuner rectifies the pulse voltage extracted from a winding other than the high voltage winding that generates the above anode voltage.
Video output circuit 9 In many cases, a function for supplying power to main circuits such as a vertical deflection output circuit is added to reduce costs. FIGS. 1 and 2 each show a conventional flyback transformer.

In FIG. 1, reference numeral 1 denotes a flyback transformer, the primary winding of which is supplied with power through terminal 2J. A high voltage output voltage serving as the anode voltage of the picture tube is taken out from a terminal 3 connected to the secondary winding of the flyback 1 Herance, and a focus voltage of the picture tube is taken out from a terminal 4. In addition, from terminal 5 of the tertiary winding, a power source for a vertical deflection output circuit that rectifies the positive retrace pulse voltage is taken out, and from terminal 6, a dyuna that rectifies the negative retrace pulse voltage, and a video intermediate frequency Power for small signal circuits such as amplifier circuits is taken out. Further, from the terminal 7 of the primary winding, a power source for a video output circuit obtained by rectifying the positive retrace pulse voltage is taken out. In addition, in Figure 2, 8 is a flyback transformer, terminals 2, 4, and 6.7 are the same as those shown in Figure 1, and terminals 6 and 7 are used for power supply and video output of the small signal circuit, respectively. The circuit is powered. The power for the vertical deflection output circuit is not taken out from this flyback transformer 8, but is taken out from the power transformer of, for example, a 7-channel television receiver.

Here, the power supply of the small signal circuit used at a relatively low voltage generates a negative pulse voltage as shown in FIG. 3, and rectifies and extracts the positive polarity portion Vs of the scanning period portion having a long conduction period. In addition, video output circuits that require relatively high power,
The power supply for the vertical deflection output circuit etc. generates a positive pulse voltage as shown in FIG.
is rectified and extracted. However, when rectifying a positive pulse voltage, for example, when there is no resistor R1, the first
A voltage as shown by the solid line AO in FIG. 5 is applied to the anode of the diode DI connected to the illustrated terminal 5, and a current as shown by the solid line Bo flows. In this way, the peak current is quite large, so the load during the retrace period is large,
Similarly, the high-voltage load fluctuation rate of the high-voltage output voltage from the terminal 3, which utilizes the positive pulse during the retrace period, is significantly worsened.

For this reason, conventionally, a resistor R1 is inserted in series with the diode D1 to suppress the peak current.

The high voltage output voltage from this terminal 3 is 0111A.
The high voltage output voltage when the high voltage load current is 1 mA is set as E HTo, and the high voltage output voltage when the high voltage load current is 1 mA is [E l-I
When the high voltage load current is changed from On+A to 1 mA, the high voltage load fluctuation rate η is expressed as 0°.

Here, as the resistance value of resistor R1 is increased, the high-voltage output voltage E t-l T + decreases as shown by the broken line ■a in FIG. 6 (Δ), and the high-voltage load fluctuation rate η decreases as shown in FIG. ) dashed line ■
As shown in a, there is a slight improvement. In addition, the power supply voltage (voltage at terminal 5) supplied to the vertical deflection output horn circuit is shown in Figure 6 (
The high voltage load current 1n decreases as expected on the broken line 11a of C).
When 1Δ, the current flowing into the flyback transformer 1 from the terminal 2 decreases as shown by the broken line IVa in FIG. 6(D),
Historically, the high voltage load current was changed from -OmA to 11Il8 μ
The power fluctuation of terminal 5 at the time of IC is shown by the broken line V in Figure 6 ([3)]
As shown in a, it rises and then falls. In addition, Fig. 6 (Δ) ~
The horizontal axis in (D) is the same as that shown at the bottom of FIGS. 6(0) and (E). In this way, if the resistor R1 is replaced by a resistor R1, the high voltage output voltage and the voltage at the terminal 5 will decrease, and the improvement in the high voltage load fluctuation rate will be relatively small.

Similarly, a resistor R2 is inserted in the circuit for taking out the power of the video output circuit which uses positive polarity pulses. In Figure 2, when the value of resistor R2 is increased, the high voltage output voltage FHT+, the high voltage load fluctuation is η, and the high voltage load current is Om.
The voltage fluctuation at terminal 7 when changing from A to 1 mA, and the voltage at terminal 7, respectively, are shown by the broken lines Vla-I in Fig. 7 (△) to (D).
It changes as shown in Xa. In addition, Fig. 7 (A) to <D)
The horizontal axis in is the same as that shown at the bottom of Fig. 7 (D>).As shown in these figures, if the resistor R2 is set to a value, the high voltage output voltage and the voltage at the terminal 7 decrease, and the terminal voltage due to high voltage load current fluctuations decreases. It has many drawbacks, such as the voltage fluctuations of 7 and the high voltage load fluctuation rate not being improved compared to A.

Therefore, when it is necessary to reduce the high-voltage load fluctuation rate such as in a high-end machine, for example, a negative pulse voltage is generated from the flyback transformer 1 and rectified (supplied to the vertical deflection output circuit). In this case, the number of turns of the winding will be about 8 times that of when using positive polarity pulses, and the pulse voltage during the retrace period will also be about 818 times higher, so the insulation of the winding and the reverse withstand voltage of the rectifier diode A will be There was a drawback that the 2] must be raised high.

The present invention eliminates the above-mentioned drawbacks and will now be described in conjunction with FIGS.

FIG. 8 shows a circuit diagram of a first embodiment of the flyback 1 to lance according to the present invention. In the same figure, the same parts as in FIG. 10 is horizontal drive 1~
11 is a horizontal output transistor. The collector of this horizontal output transistor 11 is connected to one end of the primary winding N+2 of the flyback transformer 1. Flyback 1 to Lens 1 are primary windings N+1. NI2
．． To secondary winding N21/N271.Tertiary winding N31~N
33. One end of the primary winding N u is 9i;
It is connected to child 2 and is supplied with power, and the primary winding Nl
The positive pulse voltage generated when a horizontal deflection pulse flows through + and N+2 is applied to the primary winding N-, which is divided at an appropriate ratio.
, u, ' N +2 is taken out from the intermediate tap, passes through resistor R2, is rectified by die A-D2, and is connected to capacitor C.
1 and output from terminal 7 as a power source for the video output circuit that drives the picture tube's shadow t4. One end of the secondary winding N2+ is connected to the automatic beam current limiting circuit via terminal 12, and between the secondary windings N2+ and N22, N23 and N
A rectifier diode D3. The secondary winding N24 is connected to the terminal 3 through a rectifier diode D5 and a resistor R3 for shock protection due to discharge inside the picture tube. The positive pulse voltage is rectified and output from this terminal 3 as the anode voltage of the picture tube. Along with this, the secondary winding N22. is divided at an appropriate ratio. The voltage taken out from the center tap of N23 is outputted from terminal 4 via variable resistor V1 as a single orifice voltage of the picture tube.

The voltage generated in the tertiary winding N 3+ of the flyback transformer 1 is output as the heater voltage of the picture tube from the terminal 13 via the voltage adjusting resistor RI.

In addition, the tertiary winding N32°N33 divided at an appropriate ratio
The intermediate tap of is grounded, and the negative pulse voltage generated in the tertiary winding N32 is rectified by the diode D6, passes through the protective resistor R5, and is smoothed by the capacitor C2. Juna.

It is supplied to small signal circuits such as video intermediate frequency amplification circuits. Further, one end of the tertiary winding N33 is connected to the anode of the diode [)1, and the anode of this diode D1 is connected to one end of the inductance element 11 for suppressing the peak current. The other end of the inductance element 1-1 is connected to the terminal 5 and the other end of the inductor C3 whose one end is grounded. The positive polarity ↑ 1 pulsed current F1 generated in the tertiary winding N33 is rectified by the diode D1, passes through the inductance element L1, is smoothed by the capacitor C2, and is supplied to the vertical deflection output circuit. be done.

Here, when the inductance value of the inductance element L1 is increased, the high voltage output voltage JJ: l: II T +
increases as shown by the solid line (2) b in FIG. 6(A) and then remains low, while the high voltage load fluctuation rate η rapidly decreases and improves as shown in the solid line (2) b in FIG. 6(B). In addition, the voltage supplied to the vertical deflection output circuit, that is, the voltage at terminal 5, and the current flowing into the flyback transformer 1 from terminal 2 are shown in Fig. 6 (C).
, solid line ■b in (D).

As shown in IV b, it decreases as before. Furthermore, by changing the high-voltage load current from OmA to 1mA, the voltage fluctuation at terminal 5 at the IC decreases as shown by the solid line vb in Figure 6(E)]
Ru.

In addition, the inductance value of the inductance element [1] is
When 0μH and 2oμH are selected, the voltage and current waveforms at the anode of each diode D1 are shown in Fig. 9<A), ([
3>. Here, the solid line A1゜△2 shows the voltage waveform,
Solid lines B+ and B2 indicate current waveforms. As shown in FIGS. 9(Δ) and (B), as the inductance value is increased, the current conduction period becomes longer and the interruption of the current peak point with respect to the voltage peak point becomes larger. In addition, the collapse of the peak of the pulse voltage waveform shown in Figure 55 and the sudden voltage change part at the right shoulder are eliminated,
The voltage waveform is approximately the same as the waveform when no power is supplied to the vertical deflection output circuit. Also, from Figure 6(C), 20μH
In order to obtain a voltage at the terminal 5 that is approximately equal to the inductance element L1, the resistor R1 may be set to 4.7Ω in the circuit shown in the first diagram.
The voltage waveform and current waveform shown in Fig. 9(C) are the solid line Δ3.
．． It is as shown in B3. This figure 9 (B), (C
), the peak value of the current is almost the same value, but the current conduction period is longer with the inductance element 1, and the voltage waveform of the odd-numbered harmonics at the peak is also different. There is no distortion and there are no sudden voltage changes, resulting in an ideal waveform. Further, in FIG. 9(C), the peak points of voltage and current are approximately the same, whereas in FIG. 9(B), the peak point of current is delayed from the peak point of voltage. Therefore, the conduction time of the diode D+ and the time of the voltage peak point are shifted by -, and the high-voltage load fluctuation rate η is rapidly reduced and improved as shown in FIG. 6() 3).

Furthermore, the C flyback 1 is caused by the inductance element L1.
-The harmonic tuning point of lance 1 can be changed,
High voltage output voltage F shown in Figure 6 (actual FA I b of A)
It is possible to increase the efficiency of the flyback transformer 1 by selecting the inductance value that maximizes HT+. On the other hand, when this inductance cable 1-1 is inserted, the current flowing into the flyback transformer 1 from the terminal 2 is approximately the same value as when using the resistor R1 as shown in FIG. As shown in Fig. 6 (), the stability of the power supply of the flat deflection output circuit output from terminal 5 is improved by using the inductance element 1-1.In other words, the output increases without increasing the input. This improves the efficiency of the flyback transformer 1.

FIG. 10 shows a circuit diagram of a second embodiment of the flyback transformer of the present invention. In this figure, the same parts as in FIGS. 2 and 8 are designated by the same reference numerals, and their explanations will be omitted. In Figure 10,
The intermediate taps of the primary windings NI+ and N+2 of the flyback transformer 8 are connected to one end of the inductance element L2, and the inductance element L is connected to one end of the inductance element L2 to suppress the peak current.
The other end of the rectifying diode D2 is connected to the anode of the rectifying diode D2, and the cathode of the diode D2 is connected to the terminal 7 and the other end of the capacitor C1 whose one end is grounded. The positive pulse voltage generated in the primary winding Nn passes through an inductance element L2 and is rectified by a diode D2.
The signal is further smoothed by a capacitor +tC+ and supplied to a terminal 71: a video output circuit.

Here, when the inductance value of the inductance element [2 is increased, the high voltage output voltage E l-I T + , i
? ': i voltage load fluctuation rate °η, voltage L1- fluctuation at terminal 7 when changing high voltage load current from Qm8 to 1111A,
Terminal 7 voltage 1.1, respectively, Fig. 7 < Solid line v of A)-(D)
There are changes as shown in Ib to IXb. Also, Figure 11 (
A).

(B) The inductance of the inductance element L2 from which substantially equal voltages can be obtained from the terminal 7 ("1 to /1.
Ou H and the resistance of resistor R2 (IY
Diode 1) Anor-1 of 2 when l is 100
We accept voltage and current waveforms ranging from ~. Here, the solid line AI,
Δ5 indicates a voltage waveform, and B, 1.85 indicates a current waveform. As shown in FIG. 11 (A>, (B)), when the inductance cable 1-2 is used, the current conduction period is longer, the peak value of the current is smaller, and the peak point of the current is the peak point of the voltage. This current delay improves the high-voltage load fluctuation rate η as shown in Figure 7 (B), and by changing the value of inductance L2, the high-voltage output voltage EHT+ increases. The efficiency of the flyback transformer 8 can be increased by changing the value to take the maximum value shown in FIG. This is almost the same as when using .

In this way, by using the inductance element L1 or L2 instead of the resistor R1 or R2, the peak value of the current flowing through the rectifying diode D1 or D2 is suppressed, and the peak point of the current is changed to the voltage The high voltage load fluctuation rate η can be reduced later than the peak point of . For this reason, for example, it is not necessary to generate negative polarity pulses from flyback 1 to ramme 1 and supply them to the vertical deflection output circuit, and the number of turns of the windings is reduced, which improves the insulation of the windings and the reverse withstand voltage of the diode. It is low cost and the cost is low. Furthermore, the abnormal pulse voltage generated during discharge within the picture tube is small because the number of turns is small, and the current generated at that time is also small due to the small number of turns of the inductance element L1.
It is suppressed by L-2 and the diode [ ] 1D2 etc. are sufficiently protected. Also, the resistance RI.

Since the inductance wires L+ and L2 have smaller power loss and generate less heat than R2, it is possible to miniaturize the element.

Furthermore, an inductance element L+.

By appropriately selecting the inductance value of 1-2, the tuning point for the harmonics of the flyback transformer 1.8 can be changed to obtain the maximum high voltage output mill, and the efficiency of the flyback transformer can be increased. .

Note that the resistor R2 at J3 in FIG. 8 may be replaced with the inductance element 12 as in FIG. 10, and the inductance element L1 is connected between one end of the tertiary winding N33 and the anode of the diode D+. Alternatively, the inductance element L2 may be connected between the anode of the diode D2 and one end of the capacitor C+, and is not limited to the above embodiment.

As mentioned above, the flyback lance according to the present invention is
It has at least a primary winding and a secondary winding among a primary winding on the low voltage side, a secondary winding on the high voltage side, and a tertiary winding for pulse generation, and the primary winding and/or the tertiary winding A flyback lance that extracts a positive pulse voltage from the winding, rectifies and smoothes the pulse voltage using a rectifying element and a smoothing element, and supplies it to a circuit that requires relatively high power. Since an inductance element is provided in series with the rectifying element between the terminal for taking out the positive pulse of the line and the smoothing element,
The high-voltage load regulation rate has been improved, which reduces the number of turns of the winding, requires less winding insulation, and lower reverse withstand voltage of the rectifying element, resulting in lower costs.Also, smaller inductance elements are used because power loss is lower than before. In addition, the inductance element is set to an inductance value that makes the high output voltage extracted from the secondary winding higher than when there is no inductance element, which improves the efficiency of the flyback transformer. It has features such as improved performance.

[Brief explanation of the drawing]

Figures 1 and 2 are individual circuit diagrams of a conventional flyback transformer, Figures 3, 4, and 5 are voltage and current waveform diagrams of various parts of the flyback transformer shown in Figure 1, and Figure 6. (
A) to (E) are characteristic diagrams when the constants of the resistance R+ and the inductance system 11 shown in FIGS. 1 and 8 are changed,
Figure 7 <A) to (D> are the resistances R shown in Figures 2 and 10.
2. Characteristic diagrams when changing the constant of the inductance element L2, FIGS. 8 and 10 are circuit diagrams of each embodiment of the flybank 1-lance according to the present invention, and FIGS. 9 (A) to ( C
), FIGS. 11(A) and 11(B) are electric J+ waveforms and current waveform diagrams of each part of FIGS. 1, 2, 8, and 10. 1.8...Flyback 1~Lance, 3・~7,12
゜13...Terminal, to C1, C3...21,
To Dl・D6...Diode, Ll, l-2...Inductance wire, R+...1 (5...Resistance, Nu
, N+? ...Primary winding, N21...N24...2
Next winding, to N31/N31...Third winding. Figure 6-R+In] -127asecm - Clear space [μ5ec] Figure 1 Two days ago [psecl

Claims (2)

[Claims] (1) It has at least a primary winding and a secondary winding among a primary winding on the low voltage side, a secondary winding on the high voltage side, and a tertiary winding for pulse generation, and the primary winding and /or Take out a positive pulse voltage from the tertiary winding, rectify and smooth the pulse voltage using a rectifying element and a smoothing element, and supply relatively high power to the covering circuit. A flyback transformer characterized in that an inductance element is provided in series with the rectifying element between the terminal for taking out the positive pulse of the secondary winding and/or the tertiary winding and the smoothing element. . (2) The inductance element is connected to the secondary winding j, and the high B-output voltage taken out by the inductance element is
1. The flyback lance according to claim 1, wherein the flyback lance is set to have an inductance value that is higher than that of the flyback lance.