SWITCHING POWER SOURCE DEVICE

• Main Author: DOI MASANORI
• Format: Patent
• Language: English; Japanese
• Published: 08.06.2015
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PROBLEM TO BE SOLVED: To provide a switching power source device that is able to prevent heat generation and firing of a switching transistor resulting from, for example, short circuit on the load side connected to the DC output side, by further reducing the efficiency of power resulting from constant flow of current in a start resistance.SOLUTION: A switching power source device is designed such that a DC input voltage is supplied to the primary coil (n1) of the converter transformer (T1) by a switching operation that is on/off switched according to a voltage caused in the control coil (n3) of a converter transformer (T1), and a DC output voltage is obtained from a secondary coil (n2). The switching power source device comprises: a start resistance (R1) that causes a start current to flow in the base of a switching transistor (Q1) at the time of start, thereby starting it; connection control circuits (CN1, CN2) that connect/disconnect the DC input side and the start resistance (R1); and an unstable multi-vibrator (AMV) that oscillates and outputs a control pulse for the connection control operation. 【課題】起動抵抗に常時電流が流れることによる電力の効率をより一層低減し、直流出力側に接続された負荷側に短絡などが起こることによりスイッチングトランジスタが発熱・発火することを防止することができるスイッチング電源装置を提供する。【解決手段】直流入力電圧を、コンバータトランス（Ｔ１）の制御巻線（ｎ３）に生じる電圧に応じてオンオフが切り替わるスイッチング動作によって、コンバータトランス（Ｔ１）の一次巻線（ｎ１）へ供給し、二次巻線（ｎ２）側から直流出力電圧を得るスイッチング電源装置において、起動時に起動電流をスイッチングトランジスタ（Ｑ１）のベースに流して起動させる起動抵抗（Ｒ１）と、直流入力側と起動抵抗（Ｒ１）の接続をオンオフさせる接続制御回路（ＣＮ１、ＣＮ２））と、その接続制御動作のための制御パルスを発振出力する無安定マルチバイブレータ（ＡＭＶ）を設けたことを特徴とする。【選択図】図１