JPS59181961A - Switching type dc power source with auxiliary power source for switching control circuit - Google Patents

Abstract

PURPOSE:To increase the economy of a DC power source by employing a voltage across one of two condensers in a double voltage rectifier as an auxiliary power source input for a switching control circuit. CONSTITUTION:A double voltage rectifier is composed of diodes D1, D1' and condensers C1, C1', and this output is inputted to a DC/DC converter which contains a transistor Q1, and the prescribed DC power source output is obtained. A voltage generated across the condensers C1 or C1' of a double voltage rectifier is applied to an auxiliary power source 1 for a switching controller 2.

Description

[Detailed description of the invention] It is something to do.

Switching type DC power supplies are generally used.

As shown in Figure 1, AC input from a commercial power supply is rectified by diode D1, converted to DC by F wave by capacitor CI, and this DC output is intermittent by transistor Q+.
The voltage is converted by transformer T1 and rectified by diode D2 and capacitor C2.

A switch using a switching type DC/DC converter that generates E waves to obtain the necessary DC output.

It is the source of tengumi. Here, in order to stabilize the DC output, the DC output is compared with the reference voltage and the transistor Q
It has a switching control circuit 2 that controls the on time of +.

Normally, this switching control circuit 2 includes a diode D1
+Voltage created by capacitor C1 (for example.

It is constructed using ICs and transistors that cannot be used with AC 100V input and DC 140V input. Therefore, it is necessary to separately provide an auxiliary power source for the switching control circuit, and this requires a relatively small capacity DC power source.
/DC converter 1 is used to obtain the required direct current from the rectified output of diode DI and capacitor C1. Such an auxiliary measure rj,1 is as shown in FIG.

An automatic type DC/DC converter such as a professional, ging-o/lator is used.

By the way, in a DC power supply device, when a large wattage is required for DC output, it is necessary to increase the size of components such as the L-run raster 91, and the ON time of the single transistor Q1 is required to be long. If the on-time of transistor Q+ becomes longer, the flyback voltage during off-time will increase and damage may occur.

In order to solve this drawback, the above-mentioned AC input is voltage-doubled and rectified to obtain a rectified output with twice the voltage as in the case of Fig. 1, and this is input to the DC/DC converter.
There is a way to prevent the on-time from becoming too long by flowing 1/2 the current. in this case.

Transistor Q of DC/DC converter J for auxiliary power supply
2 and transformer T2 (see Figure 3) become unnecessarily large.

The present invention aims to solve these drawbacks in an economical manner.

That is, one aspect of the present invention is to provide a rectifier circuit 111 for AC input as described above.
6, in a DC power supply device that uses a voltage doubler rectifier circuit to obtain a large number of watts/1 as a DC output,
The voltage across both terminals of one of the two capacitors in the single voltage rectifier circuit is used as the auxiliary power input for the switching control circuit. According to such a configuration, it is not necessary to use large-sized circuit elements of the auxiliary power supply while increasing the wattage of the output of the DC power supply, and therefore it is possible to use an economical DC power supply.

An embodiment of the present invention will be described below with reference to FIG. 2. In FIG. 2, a voltage doubler rectifier is created by diodes DI and D1' and a capacitor C1+(:+').

This is the main DC/DC controller including Trannostar Q+.
-The required DC power output is obtained.

For the auxiliary power supply 1 for the Ushida switching control circuit 2.

A direct current of 1/2 the voltage generated across the capacitor C1 or id Cl' of the voltage doubler rectifier circuit is inputted. With this configuration, although the DC/DC converter of the auxiliary power source uses a single voltage rectifier circuit, it does not have the disadvantage of becoming unnecessarily large and expensive, and is therefore very practical.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional switching type power supply device. FIG. 2 is a configuration diagram of a conventional switching type power supply device. Figure 3 shows DC as an auxiliary power source for the switching control circuit.
FIG. 2 is a diagram showing an example of a /DC converter. 1. Auxiliary power supply, 2. Switching control circuit.

Claims (1)

[Scope of Claims] J: A rectifier circuit that rectifies an AC power supply, and a switching type main D for obtaining a DC of a predetermined screw pressure from the output of the rectifier circuit.
A C/DC converter, a switching control circuit that monitors the output DC voltage of the main DC/DC converter and controls the switching operation of the switching element of the main DC/DC converter, and the switching control circuit from the output of the rectifier circuit. In a switching type DC power supply device having an auxiliary power supply consisting of a DC/DC converter for obtaining power for use, a voltage doubler rectifier circuit is used as the rectifier circuit, and the voltage across one of two capacitors in the voltage doubler rectifier circuit is changed by the switching method. A switch characterized in that it is configured to be used as an input of an auxiliary power supply for a control circuit. Switching type DC power supply device with auxiliary power supply for switching control circuit.