JPS58159669A - Rectifying circuit - Google Patents

Abstract

PURPOSE:To reduce the capacity of a smoothing condenser by maintaining the smoothing condenser at peak voltage for a while and discharging it in a short time. CONSTITUTION:When a thyristor SCR is OFF, a smoothing condenser C1' is charged until it becomes the peak value of the input peak voltage through a diode D1, and lowered after reaching the peak value. Then, the output voltage V0' is similarly lowered, and when the voltage difference between the output voltage V0' and the voltage VC1 across the condenser C1' exceeds the Zener voltage of a Zener diode DZ1, the diode ZD1 is conducted, a thyristor SCR1 is fired, and conducted. Accordingly, the condenser C1' is connected to the output terminal 2, and the output voltage V0' is maintained by the discharge of the condenser C1'.

Description

Detailed Description of the Invention (al) The technical field of the invention relates to a capacitor input type rectifier circuit, and relates to a rectifier circuit that can reduce the capacitance of a smoothing capacitor and suppress the peak value of input AC current. Technology and Problems Figure 1 is a circuit diagram of a conventional capacitor input type rectifier circuit.
FIG. 2 is a time chart of waveforms in the case of FIG. 1, where the symbol is the output voltage and @ is the 5emt input to the rectifier circuit.

In the diagram, E is a commercial AC power supply, RC is a rectifier, and C is a rectifier.
I is a smoothing capacitor, 1 is a load, ■ is an output voltage, and Iin is an input alternating current to the rectifier circuit.

In the conventional capacitor input type rectifier circuit, as shown in Fig. 2, the currents mu, a, a are transferred from the commercial commercial current @E to the rectifier circuit.
After charging the smoothing capacitor C0, the current IKt is supplied, and brittle shaping 15 is performed.

When the output voltage (■, ) reaches its maximum value, the electric charge stored in the smoothing capacitor C, supplies current to the load 1, and the voltage at both ports of the smoothing capacitor C1 decreases, causing the prich type JIR device to When the voltage regulated by RC reaches point C, which is higher than the voltage at both ports of the smoothing capacitor C1, the commercial AC power supply E supplies the charging current of the smoothing capacitor CI and the current to the load l again. Become. The input AC current Iin between points bc and bc, which supplies current from the smoothing capacitor C to the load 1, is almost 0, but a large peak current occurs when the charging current of the smoothing capacitor C flows.

Therefore, the input AC current RI i n is as shown in Figure 2, and has the disadvantage of a very poor power factor.

In addition, since most of the time when the load 1 (·) energy is supplied to the molecule x, = -beak capacitor C8, a capacitor with a large capacity is required, and there is also the disadvantage that the R adjustment device becomes large.

(c) Purpose of the Invention The purpose of the present invention is to eliminate the above-mentioned drawbacks and create a human-powered capacitor! An object of the present invention is to provide a rectifier circuit that can reduce the capacity of a smoothing capacitor in an I-current circuit and reduce the peak value of input AC current.

(d) Structure of the Invention In order to achieve the above object of the present invention, in a capacitor input rectifier circuit, a smoothing capacitor is connected in parallel via a diode to a circuit in which a commercial AC input is passed in both waves. The connection point between the smoothing capacitor and the diode is connected to the output terminal via a thyristor, and the gate of the thyristor is fired by the difference between the voltage of the smoothing capacitor and the voltage of the output terminal, so that the smoothing capacitor can reduce the load. The present invention is characterized in that the point in time at which the energy V supply starts is not at the point where the rectified voltage is adjusted, but at the point at which the f% pressure has fallen to a certain extent and the thyristor is fired.

(e) Implementation of the invention The implementation of the present invention will be explained below with reference to the drawings.

Figure 3 is a circuit diagram of a capacitor input type rectifier introduction path according to an embodiment of the present invention, [Figure 4 is a time chart of waveforms in the case of Figure 3, where the input/output voltage is input and @ is the input AC current to the rectifier circuit. be.

Items with the same functions as those in Figure 1 are indicated by the symbol -f0C1.
' is the smoothing capacitor, ■o' is the voltage at both ports of load 1 at the output I, the input AC current of the rectifier circuit -\ is at the Ii port, D,
fi diode, ZD, is Zener diode, SCa,
is a thyristor, R,, R,, R, is a resistor, R8 is for current suppression, R8 is for Zener diode protection,
R1 is for countermeasure against Zener diode leakage current. 2,
2'i- is the output terminal, and V'' (lfl indicates the voltage at both ports of the smoothing capacitor.

The input alternating current is passed through the bridge shape rectifier RC1 and supplied to the next stage circuit. When the thyristor SCR, is off, the smoothing capacitor C,/ is the diode DI.
light t until one peak of input voltage is reached from point a' through
be done. The commercial AC power source E is a sine wave, which decreases after reaching its peak value.

As the output voltage V, / also decreases,
When the potential difference between the output voltages ``,'' and the voltage VC+ at both ports of the smoothing capacitor exceeds the zener voltage of the zener diode ZD (point b), the zener diode ZD.

becomes conductive 5, and the thyristor SCR is fired and turned on. Therefore, the -+beak capacitor C1' is not connected to the output terminal 2, and the output voltage v,' is maintained by discharging the smoothing capacitor C1'. When the input voltage rises again and becomes lower than the voltage at which the smoothing capacitor C1' is being discharged (01'
The Twiristor SCR is reverse biased, extinguished and turned off.

In the circuit of the present invention, the smoothing capacitors C, l
Since Lj-t' is easily left at the peak voltage and discharged for a short time, the capacitance of the smoothing capacitor C,1 can be reduced compared to the conventional circuit when the ripple voltage is set to the same value as PI. (In the case of 50 cycles, it can be reduced to about 1/2.) Therefore, if the rectifier has a large capacity, other elements can be added (even 7 can be made smaller. For example, the peak value for charging the smoothing capacitor C1' becomes smaller due to the capacitance ratio of the smoothing capacitor, so it becomes much smaller. Smoothing capacitor C8
Since it is a discharge section of

FIG. 5 is a circuit diagram of a center tag type 11 capacitor input type circuit according to another embodiment of the present invention.

Components in the figure that have the same functions as those in FIG. 3 are indicated by the same symbols.

T is a transformer, D, , D are distortion current devices, D1' is a diode, L is a choke, C and r are smoothing capacitors, 5CFtf
fi is a thyristor, and R4, R, is a resistor.

Using the pressure return device T in the circuit shown in Fig. 5, the center tag type Ift
This is a serious matter. Also, instead of the Zener diode ZD in the case of Fig. 3, the thyristor 8 is
(JL is used to ignite 3, or a choke L is used instead of resistor R1. The main operation is the same as in case 1 of Fig. 3.) This choke L and the 39th resistor R, are the thyristor S
CR and SC electric currents do not require surges when they have sufficient resistance to current.

Of course, dividing the voltage using resistors without using a Zener diode and using a choke L can also be applied to the Brissoti rectification type shown in FIG.

(f) Effects of the Invention To explain more clearly, according to the present invention, the smoothing capacitor can be made extremely small, the rectifier can be downsized even if the rectifier has to be moved a lot, and the power factor can be reduced. It has the same effect as above.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional capacitor input type rectifier circuit, Figure 2 is a time chart of waveforms in the case of Figure 1, and Figure 3 is a circuit diagram of a conventional capacitor input type rectifier circuit.
Figure 4 shows a circuit diagram of a capacitor input type rectifier circuit according to an embodiment of the present invention, Figure 4 shows a time chart of waveforms in the case of Figure 3, and Figure 5 shows a capacitor input type J1 flow circuit according to an embodiment of the present invention. FIG. 3 is a circuit diagram of a center-tap type unit. In the figure, Eta commercial AC IM, RC, Brinona type rectifier,
D,, D,il rectifier,C+,C,',c,
y n smoothing capacitor, 1 is load, 2, 2' are output terminals, D,, D,' are diodes, R, ~R, U resistance, SC
R,,SCR,iJ thyristor,zDI is Zener diode,V,,V. ' indicates the output voltage, and Iin and Iin' indicate the human-powered alternating current. Agent: Patent Attorney Hiroshi Matsuoka 1-1
-j Kōō; Akira 1 Figure 2 Hirama Akira 5 Figure Ryo 4 Figure 1 mouth

Claims (1)

[Claims] In a capacitor input type rectifier circuit, a smoothing capacitor is connected in parallel via a diode to a circuit that receives both AF waves from a commercial AC input, and a connection point between the smoothing capacitor and the diode is connected to an output increaser via a thyristor. A rectifier circuit characterized in that the gate of the thyristor is ignited by the difference between the voltage of the smoothing capacitor and the voltage of the output terminal.