JPH042980U

JPH042980U -

Info

Publication number: JPH042980U
Application number: JP4197990U
Authority: JP
Priority date: 1990-04-19
Filing date: 1990-04-19
Publication date: 1992-01-10

Description

[Brief explanation of the drawing]

第１図は本考案の実施例装置の回路図、第２図
はその実施例装置の動作説明のためのもので、主
負荷電流に対する各整流ダイオードの両端間電圧
の変化を示す図である。第３図は従来例装置の回
路図である。ＦＣ……一次側回路、ＭＳＣ……主二次側回路
、ＳＳＣ……副二次側回路、Ｔ１……コンバータ
トランス、ＳＨ１……第１の主整流平滑回路、Ｓ
Ｈ２……第２の主整流平滑回路、Ｄ４……整流ダ
イオード、Ｃ４……平滑コンデンサ、Ｄ６……整
流ダイオード、Ｃ８……平滑コンデンサ、ＩＣ３
……比較回路、ＴＨＹ……サイリスタ（短絡素子
）。 FIG. 1 is a circuit diagram of a device according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of the device according to the embodiment, and is a diagram showing changes in voltage across each rectifier diode with respect to main load current. FIG. 3 is a circuit diagram of a conventional device. FC...Primary side circuit, MSC...Main secondary circuit, SSC...Sub secondary circuit, T1...Converter transformer, SH1...First main rectifier smoothing circuit, S
H2... Second main rectifier smoothing circuit, D4... Rectifier diode, C4... Smoothing capacitor, D6... Rectifier diode, C8... Smoothing capacitor, IC3
... Comparison circuit, THY ... Thyristor (short circuit element).

Claims

[Claims for Utility Model Registration] The converter transformer T1 has a primary side circuit FC, a main secondary side circuit MSC, and a sub-secondary side circuit SSC, and the converter transformer T1 has a primary side winding n1,
It has a main secondary winding n2 and a sub secondary winding n3, the primary circuit MSC is connected between the input terminals IN, IN and the primary winding n1, and It has a control circuit CC, a switching element TR1, and an overcurrent detection circuit R3, and the control circuit CC also outputs a control signal for constant voltage control of the main output voltage in response to the input of the output voltage detection signal. , and output a control signal for protecting the load from overcurrent in response to the input of the overcurrent detection signal, respectively, and the switching element TR1 is inserted in the current path IP of the primary winding n1. , and performs a switching operation in response to the input of each of the control signals, and the overcurrent detection circuit R3 detects an overcurrent flowing through the current path IP and controls an overcurrent detection signal related to the detection. The main secondary side circuit MSC is input to the circuit CC, and the main secondary side circuit MSC is the main secondary side winding n2.
and the main output terminals MO, MO, and outputs the voltage induced in the main secondary winding n2 as a DC output voltage to the main output terminals MO, MO; The next circuit SSC includes the sub-secondary winding n3
and the secondary output terminals SO, SO, and outputs the voltage induced in the secondary winding n3 as a DC output voltage to the secondary output terminals SO, SO. The side circuit MSC includes first and second main secondary rectifying and smoothing circuits SH1, SH2, an output voltage detection circuit OVC, a comparison circuit IC3, and a shorting element T.
HY, the first main secondary rectifier smoothing circuit SH1 is connected between the main secondary winding n2 and the main output terminals MO, MO, and Diode D4
The second main secondary rectifying and smoothing circuit SH2 rectifies and smoothes the induced voltage of the main secondary winding n2, and includes a second rectifying diode D6. Yes, the output voltage detection circuit OVC detects the magnitude of the output voltage from the first main secondary side rectification and smoothing circuit SH1, and outputs an output voltage detection signal related to the detection to the control circuit CC, The comparison circuit IC3 has a first rectifier diode D4 at one input section - and a second rectifier diode D4 at the other input section +.
rectifier diodes D6 are connected to each other, and the magnitudes of the voltages across both rectifier diodes D4 and D6 are compared, and the voltage across the first rectifier diode D4 is equal to that of the second rectifier diode D6. When the voltage becomes larger than the voltage between both ends, it outputs an output that turns on the short circuit element THY, and the short circuit element THY responds to the input of the ON output from the comparator circuit IC3 to the main output terminals MO, A multi-output switching power supply device that short-circuits an MO.