JPH0213267A - Voltage doubler rectifier power source provided with auxiliary charging circuit - Google Patents

Abstract

PURPOSE:To shorten charging time of a charging capacitor by additionally providing an auxiliary charging circuit to a voltage doubler rectifier power source. CONSTITUTION:An AC power source AC is connected through a voltage doubler rectifier section DR comprising a leakage type transformer T, diodes D2-D3 and a capacitor C1 with a charging capacitor C2, and an auxiliary charging diode D1 is connected between the secondary winding N2 of the transformer T and the charging capacitor C2. When a trigger signal is applied onto a load Xe such as a xenon lamp, the capacitor C2 is discharged through a coil L and light is emitted from the xenon lamp. Consequently, initial charge of the capacitor C2 is also carried through the auxiliary charging circuit D1, and when the charged voltage reaches to a predetermined level the capacitor C2 is charged only through the function of the voltage doubler rectifier section DR thus contributing shortening of charging time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a voltage doubler rectifier power supply that is also equipped with an auxiliary charging circuit, which can charge a charging capacitor at high speed, and is particularly applicable to copying machines,
Suitable as a power source for flash lamps such as facsimile machines.

Conventional technology Generally, flash lamps such as xenon lamps used for fusing in copying machines, facsimile machines, etc. or for m+ use require considerably high output, so a high voltage, large capacity capacitor is used to charge the emitted energy. , it is necessary to store a large charge. Therefore, voltage doubler rectifier power supplies were generally used.

Problems to be Solved by the Invention However, the voltage doubler rectified power supply has a problem in that the time required to charge the capacitor is slow, making it difficult to shorten the flash lamp emission interval.

An object of the present invention is to provide a voltage doubler rectifier power supply that is also equipped with an auxiliary charging circuit that can charge a charging capacitor at high speed.

Means for Solving the Problems The present invention connects an AC power supply to a charging capacitor via a transformer and a voltage doubler rectifier, and also connects an auxiliary charging diode between the secondary winding of the transformer and the charging capacitor. This constitutes a voltage doubler rectifier power supply with an auxiliary charging circuit that is characterized by being connected to the auxiliary charging circuit.

Note that the voltage doubler rectifier means not only a double voltage rectifier but also a voltage doubler of 3 or more (N double voltage).

According to the present invention, the initial charging of the capacitor is performed through the auxiliary charging circuit, and when the charging Nff pressure reaches a certain value, the capacitor is charged only by the original action of the doubler positive rectifier, and the charging starts. Contributes to speeding up N hours.

Example Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, an AC T source C includes a leakage type transformer T and a diode D2. D., connected to a charging capacitor C2 via a voltage doubler rectifier DR consisting of a capacitor C1, and connecting an auxiliary charging diode D1 between the secondary winding N2 of the transformer T and the charging capacitor C2; It is. Then, when a trigger is applied to a load xO such as a xenon lamp, the charge in the capacitor C2 is discharged through the coil L, causing the load Xs to emit a flash.

The operation of the above configuration will be explained with reference also to FIG.

First, capacitor C due to the original operation of voltage doubler rectifier DR
2, when the secondary winding N2 has a polarity opposite to that shown, the diode D31! - on the current flowing through,
When capacitor C8 is charged with the polarity shown,
When the polarity of the secondary winding N2 changes to the one shown in the figure, the secondary winding N2
2 and the voltage of capacitor C1 are added and the voltage of diode D2
The capacitor C2 is charged via the capacitor C2. The current 12 of the diode D2 at this time is as shown in the figure, and gradually increases as the capacitor C2 progresses in charging. On the other hand, in the initial stage of charging the capacitor C2, when the secondary winding N2 has the polarity shown, the capacitor C2
is charged, and the illustrated current 11 flows through the diode D1 every half wave of this polarity of the alternating current power supply AC. This current i is large at first, but stops flowing at time t when the charging voltage Vc reaches around the terminal voltage VN2 of the secondary winding N2 as the charging of the capacitor C2 progresses, and as described above, the voltage doubler rectifier sDR Only by the original operation, the capacitor C2 is charged until the time t2 when the charging voltage To reaches the final voltage. I is the charging current of capacitor C2, I=i, -)-i2
It is.

In addition, when using a leakage type transformer T,
This is to reduce inrush current and prevent damage to circuit components, and the same function can be achieved by combining an ordinary transformer T with a 1,100-inch coil L, as shown in FIG.

As described above, according to this embodiment, in addition to the operation of the voltage doubler rectifier iDH, auxiliary charging is performed by the diode D at the initial stage of charging the capacitor C2, contributing to speeding up the charging time. Furthermore, even if a small capacity capacitor C1 is used, the charging time can be shortened, resulting in miniaturization and cost reduction.

Effects of the Invention According to the present invention, since an auxiliary charging circuit is added to the voltage doubler rectifier power supply, the charging time of the charging capacitor can be speeded up, and the power supply is useful as a power supply for flash lamps of copiers, facsimile machines, etc. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the invention, FIG. 2 is a timing chart showing the same operation, and FIG. 3 is a circuit diagram showing another embodiment of the invention. M... AC power supply, T... Transformer,
DR: voltage doubler rectifier, C2: charging capacitor, N2: secondary winding, D: auxiliary charging diode.

Claims (1)

[Claims] An auxiliary charging circuit characterized in that an AC power source is connected to a charging capacitor via a transformer and a voltage doubler rectifier, and a diode for auxiliary charging is connected between the secondary winding of the transformer and the charging capacitor. Voltage doubler rectifier power supply.