JPS5825033B2 - Koden Atsuhatsu Seisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high voltage generator that generates a high DC voltage by rectifying and smoothing an AC high voltage or the AC high voltage using a combination of a DC power supply, a coil, a capacitor, and a switching element. be.

Conventional high voltage generators include 1. Transformer boost pressure type 1. Boost system using Cockcross-Walton circuit ■ Boosting method using impulse circuit ■, Boost method using piezoelectric effect ■ Boost pressure formula using bump graph Something special was known.

The present invention aims to provide a new high voltage generator different from those.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows the basic circuit of the present invention, in which the switching element 1
The switching element 2, which has a conduction period different from that of the switching element 1, alternately repeats conduction and non-conduction (ON-OFF) so that they do not become conductive at the same time.

3 is a DC power supply, 4 is a coil, and this coil 4 is wound around a core 6 in which a DC excitation coil 5 is incorporated, and the operating point of the coil 4 is set in advance by the DC excitation coil 5.
It is set at the bending point (point A) of the B-H curve in FIG. 2.

7 is a coil, and 8 is a capacitor.

When the current flowing through the coil 4 flows in the direction from the terminal a on the switching element 1 side and out from the terminal a on the coil 7 side, the operating point moves to the right on the B-H curve, and the current flows to the coil 4. It is assumed that a DC magnetic field is previously formed by the DC excitation coil 5 in such a direction that the current moves to the left when it flows in the opposite direction.

FIG. 3 shows an embodiment in which a transistor is used as a switching element, and FIG. 4 shows an embodiment in which a SIRISK is used as a switching element. In FIGS. 3 and 4, 9 is a drive transformer.

FIG. 5 shows an example in which signals obtained from a horizontal oscillation circuit 10 and a horizontal drive circuit 11 used in a television receiver are used as drive signals for switching transistors. The AC high voltage generated between the capacitors 8 and 8 is boosted and rectified by a voltage doubler rectifier circuit 12 and supplied to the anode electrode of a plan tube 13 of the television receiver.

Here, the winding 9'' is wound in the opposite direction to the winding 9', and the drive signal is used so that an electromotive force with a narrow pulse width is generated at the terminal on the side marked with the mark. and
When transistor 1 connected to winding 9' is conducting, transistor 2 connected to winding 9'' is non-conducting, and conversely, when transistor 1 connected to winding 9' becomes non-conducting, transistor 1 connected to winding 9'' is not conducting. The transistor 2 becomes conductive.

Here, the conduction period of transistor 1 connected to winding 9' is approximately 25.5 μs.1 The conduction period of transistor 2 connected to winding 9'' is approximately 38 μs, and these conduction periods depend on the pulse width and repetition time of the drive signal. It's decided.

The following is a first explanation of the operation of the high voltage generator according to the present invention.
The explanation will focus on figures.

■ First operation period (1 second) It is assumed that switching element 1 is conductive, switching element 2 is non-conductive, and there is no electrical energy stored in the coil or capacitor in advance.

A DC power source 3 having an electromotive force E is connected via a switching element 1 to a series complex in which a coil 4, a coil 7, and a capacitor 8 are connected in series.

The current flowing through the closed circuit of the DC power supply 3, switching element 1, coil 4, coil 7, and capacitor 8 is a-+ l
) Frequency 1 is determined by coil 7 and capacitor 8 depending on the direction of
This results in a sinusoidal current having a value of 1.

In this case, the coil 4 has no inductance because its core is saturated.

Here, the conduction period T1 of the switching element 1 is set to the coil 7,
If the time is made to match the half cycle time of the frequency determined by capacitor 8 (8 = 1/2T1), the current will be zero at the end of the conduction period of switching element 1, and capacitor 8
A voltage of 2E appears at the EHT terminal with respect to the ground potential.

■ During the second operating period, during which switching element 1 is non-conductive and switching element 2 is conductive, a closed circuit is formed of capacitor 8, coil 7, coil 4, and switching element 2, and in this case, DC power supply 3 is present in the circuit. However, the electrical energy stored in the capacitor 8 at the end of the period ■ causes the coil 4 to
l) A current flows in the direction of -+3 in this closed circuit, and the current becomes a sinusoidal current having a frequency 12 determined by the coil 4, the coil 7, and the capacitor 8.

In this case, since the current flowing through the coil 4 is in the direction b→a, the coil 4 acts as an inductance.

Here, the conduction period T2 of the switching element 2 is set to the coil 4,
If the time is made to match the half cycle time of the frequency determined by the coil 7 and capacitor 8 (f2 = 1/2 T2
), at the end of the conduction period of the switching element 2, the current becomes zero and a voltage of -2E with respect to the ground potential appears at the EHT terminal of the capacitor 8.

■ Third operating period ('rt seconds) Switching element 1 is conducting, switching element 2 is non-conducting, DC power supply 3 is connected to the series complex of coil 4, coil 7, and capacitor 8 via switching element 1,
The structure of the closed circuit is the same as in case (■), but in this period, the electrical energy stored in the period (■) exists in the capacitor 8 as an initial value, and the polarity of the charge stored in the capacitor 8 is is in the same direction as the polarity of the DC power supply 3, so a sine wave current with a frequency of 11, which is equivalent to when a 3E DC power supply is connected to a circuit with an initial value of zero, tries to flow in the direction from a to b.

At the end of the conduction period of switching element 1, EHT
A voltage of 4E appears at the terminal with respect to ground potential.

■ Fourth operation period (T2 seconds) Switching element 1 is non-conducting and switching element 2 is conductive, forming the same closed circuit as in case (■), but 4E is stored at both ends of capacitor 8 during period (■). initially exists.

This causes a sinusoidal current of frequency f2 to flow in the direction b→a in this closed circuit, and at the end of the conduction period of switching element 2, the current is zero and a voltage of -4E with respect to the ground potential appears at the EHT terminal.

In this way, switching element 1 and switching element 2 are alternately operated for different times T1. When it is turned OFF at T2 and repeated, a high alternating current voltage will be generated at the EHT terminal with respect to the ground potential.

Although the pure resistance of the DC power supply, coil, capacitor, and conductor mentioned above is not taken into account at all, the actual circuit includes pure resistance, and the generated voltage is also limited by it, so an infinite voltage is not generated. However, conversely, it is possible to limit the generated voltage using these.

For example, using a transistor as a switching element,
By connecting the circuit described above to the collector and emitter electrodes, a closed circuit is constructed, and the base electrode is used as a control electrode, and if the current flowing through it is connected, the current flowing in the closed circuit (collection current of a switching transistor) is controlled, and the generated voltage is also controlled.

In the above embodiment, a case where the DC excitation coil 5 is incorporated in the core 6 as a means for forming a DC magnetic field in the core 6 in advance has been described, but the DC excitation coil 5
Alternatively, a permanent magnet may be incorporated into the core 6 to constitute a means for forming a DC magnetic field.

As described above, the present invention alternately conducts 0N in different conduction periods.
-It relates to a high voltage generator composed of two switching elements that are turned off, a DC power supply, a coil, a capacitor, and a coil wound around a core equipped with means for forming a DC magnetic field, for example. When designing high-frequency high-voltage transformers (for example, flyback transformers) that rectify high-frequency AC high voltage to obtain DC high voltage, the leakage inductance, stray capacitance, etc. of the transformer have a major influence on the design, and the operation of the transformer is affected. Analysis becomes extremely difficult, and the design of flyback transformers and the like must rely primarily on experience.

On the other hand, the high voltage generator according to the present invention has a simple structure because its main components are a coil and a capacitor, rather than a transformer type that requires a primary winding and a secondary winding.

1. Leakage inductance and stray capacitance have little influence on the overall operating characteristics, resulting in characteristics as a single unit.

1. There is no effect on the operating characteristics due to the structure or arrangement, and therefore the design can be expanded, and at the same time insulation design for areas where insulation is strongly desired or areas that do not require much insulation can be done independently of the operating characteristics. It can be carried out.

It has many features such as.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram of a high voltage generator according to the present invention;
Figure 2 is a B-H curve diagram of the core around which the coil is wound.
3 and 4 are schematic circuit diagrams of other embodiments of the present invention, and FIG. 5 is a circuit diagram of an embodiment when used as a DC high voltage generator for a television receiver. 1.2... Switching element, 3...
DC power supply, 4... Coil, 5... Means for forming a DC magnetic field (DC excitation coil), 6...
...Core, 7...Coil, 8...
capacitor.

Claims (1)

[Claims] 1 A switching element is connected in parallel to both ends of a series complex in which a capacitor, a coil, and a coil wound around a core equipped with means for forming a direct current magnetic field are connected in series, and a switching element is connected in parallel to the switching element. connecting a switching element having a conduction period different from the switching element connected in series to a DC power source, and repeatedly switching the switching element into conduction and non-conduction so that the two switching elements do not become conductive at the same time; A high voltage generator characterized in that the conduction time of each switching element is made to match the time of a half cycle of the resonant frequency of a closed circuit formed by conduction.