JPH01149577A - Synchronous circuit for switching power source - Google Patents

Synchronous circuit for switching power source

Info

Publication number
JPH01149577A
JPH01149577A JP30781487A JP30781487A JPH01149577A JP H01149577 A JPH01149577 A JP H01149577A JP 30781487 A JP30781487 A JP 30781487A JP 30781487 A JP30781487 A JP 30781487A JP H01149577 A JPH01149577 A JP H01149577A
Authority
JP
Japan
Prior art keywords
power supply
switching
circuit
pulse width
power source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP30781487A
Other languages
Japanese (ja)
Inventor
Norio Sugawara
菅原 範生
Kenichi Abe
憲一 阿部
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP30781487A priority Critical patent/JPH01149577A/en
Publication of JPH01149577A publication Critical patent/JPH01149577A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To stabilize the output of a power source composed of a ringing choke converter by providing a switching circuit and making the pulse width of a horizontal synchronizing signal variable and wide. CONSTITUTION:A switching transistor(TR) 11, a damper diode 12 and a capacitor 13 for resonance are provided in parallel in a switching circuit 1 and its output terminal is connected to one end of an input side coil 14 of a transformer 2 for synchronizing signal power source supply. A power source voltage is supplied to the other end of the coil 14, the synchronizing signal detected from a CRT is supplied to the TR11 and a pulse of a pulse width different from the pulse width of the synthesizing signal is generated at both the ends of the coil 14 in accordance with the impedance of the coil 14 and the capacity of the capacitor 13. Thus, the pulse width of the synchronizing signal to synchronize the frequency of a device with the frequency of a switching power source is made variable and wide, noises are decreased and a stable action can be attained to the temperature fluctuation of the switching power source, etc.

Description

【発明の詳細な説明】 〔概 要〕 CRT表示装置用のリンギングチョークコンバータ(以
下RCCと記す)を′使用するスイッチング電源の同期
回路に関し、 高周波高電圧でスイッチングすることによるスイッチン
グノイズを低減し、回路を安定に動作させることを目的
とし、 スイッチングトランジスタとダンパーダイオードと共振
用コンデンサとを並列に設け、該並列回路の出力端を同
期信号電力供給用トランスの入力側コイルの一端に接続
したスイッチング回路を有してなり、前記同期信号電力
供給用トランスの入力側コイルの他端に電源電圧を供給
し、CRT表示装置から検出された水平同期信号を前記
スイッチングトランジスタに供給し、該水平同期信号の
パルス幅と異なったパルス幅のパルスを前記入力側コイ
ルの両端に該入力側コイルのインビーダンスと前記共振
用コンデンサの容量に応じて発生させるように構成する
[Detailed Description of the Invention] [Summary] This invention relates to a synchronous circuit for a switching power supply using a ringing choke converter (hereinafter referred to as RCC) for a CRT display device, which reduces switching noise caused by switching at high frequency and high voltage. A switching circuit in which a switching transistor, a damper diode, and a resonant capacitor are connected in parallel, and the output end of the parallel circuit is connected to one end of the input coil of a synchronous signal power supply transformer, with the aim of stably operating the circuit. It supplies a power supply voltage to the other end of the input side coil of the synchronous signal power supply transformer, supplies the horizontal synchronous signal detected from the CRT display device to the switching transistor, and supplies the horizontal synchronous signal detected from the CRT display device to the switching transistor. A pulse having a pulse width different from the pulse width is generated at both ends of the input coil according to the impedance of the input coil and the capacitance of the resonance capacitor.

〔産業上の利用分野〕[Industrial application field]

本発明は、CRT表示装置に使用する他動式スイッチン
グ電源に関し、さらに詳細には同期信号供給方式の改良
に関する。
The present invention relates to a passive switching power supply used in a CRT display device, and more particularly to an improvement in a synchronization signal supply system.

スイッチング電源は、小型、安価な電源として多くの装
置に使用されている。
Switching power supplies are used in many devices as small, inexpensive power supplies.

しかし高周波高電圧でスイッチングするため、スイッチ
ング時のノイズが発生し易く、特にCRTを使用した表
示装置の場合、画面上にそのノイズが現れ画質を低下さ
せることになる。
However, since switching is performed at high frequency and high voltage, noise is likely to occur during switching, and especially in the case of a display device using a CRT, the noise appears on the screen and deteriorates the image quality.

そこで当該表示装置の周波数とスイッチング電源の周波
数を同期させるとこのノイズが低減し、この結果スイッ
チング電源自体のシールドケースが不要になり安価とな
る。
Therefore, by synchronizing the frequency of the display device and the frequency of the switching power supply, this noise is reduced, and as a result, the shielding case of the switching power supply itself becomes unnecessary and the cost becomes low.

この場合同期信号のパルス幅が狭いと電源回路の同期が
不安定になるので、同期信号のパルス幅を広くとること
のできるスイッチング電源回路の開発が要望されている
In this case, if the pulse width of the synchronization signal is narrow, the synchronization of the power supply circuit becomes unstable, so there is a demand for the development of a switching power supply circuit that can have a wide pulse width of the synchronization signal.

〔従来の技術〕[Conventional technology]

第4図は、従来のスイッチング電源の同期回路のブロッ
ク図であり、図において2は同期信号電力供給用トラン
ス、3はリンギングチョークコンバータ(RCC)、1
4は入力側コイル、15は出力側コイル、21は水平発
振AFC回路、22は駆動回路、23は水平偏向回路、
24はワンショットマルチバイブレーク、25はエミッ
タホロワである。
FIG. 4 is a block diagram of a synchronous circuit of a conventional switching power supply. In the figure, 2 is a synchronous signal power supply transformer, 3 is a ringing choke converter (RCC), 1
4 is an input side coil, 15 is an output side coil, 21 is a horizontal oscillation AFC circuit, 22 is a drive circuit, 23 is a horizontal deflection circuit,
24 is a one-shot multi-by-break, and 25 is an emitter follower.

従来のスイッチング電源の同期回路においては、図に示
すように水平同期信号は水平発振AFC回路21に入力
され、駆動回路22で電力増幅され、CRT等の水平偏
向回路23に入力される。
In a conventional switching power supply synchronization circuit, as shown in the figure, a horizontal synchronization signal is input to a horizontal oscillation AFC circuit 21, power amplified by a drive circuit 22, and input to a horizontal deflection circuit 23 such as a CRT.

上記水平偏向回路23で発生するフライバックパルスを
ワンショットマルチバイブレータ24とエミッタホロワ
25を使用して同期信号電力供給用トランス2に供給し
ている。
A flyback pulse generated by the horizontal deflection circuit 23 is supplied to the synchronous signal power supply transformer 2 using a one-shot multivibrator 24 and an emitter follower 25.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

ところが従来のスイッチング電源の同期回路においては
、同期信号電力供給用トランス2に供給するパルスのパ
ルス幅が水平偏向回路23の電圧と回路素子等でほぼ決
まり、パルス幅を変えることが出来ない上にパルス幅が
狭いため、スイッチング電源の出力特性が不安定であっ
た。
However, in the conventional synchronous circuit of a switching power supply, the pulse width of the pulse supplied to the synchronous signal power supply transformer 2 is almost determined by the voltage of the horizontal deflection circuit 23, circuit elements, etc., and the pulse width cannot be changed. Because the pulse width was narrow, the output characteristics of the switching power supply were unstable.

またスイッチング電源の容量が大きい場合、同期信号の
電力も大きくなり、ワンショットマルチバイブレークで
同期パルス幅を広くしたとしても電力供給が困難となり
、そのためエミッタホロワ25等の電力供給用トランジ
スタが必要となり従って回路が複雑になるといった問題
点があった。
In addition, if the capacity of the switching power supply is large, the power of the synchronization signal will also be large, making it difficult to supply power even if the synchronization pulse width is widened by one-shot multi-by-break. Therefore, a power supply transistor such as an emitter follower 25 is required, and the circuit The problem was that it became complicated.

本発明は、このような問題点に鑑み、水平同期信号のパ
ルス幅を可変にして広くし、RCCで構成されるスイッ
チング電源の出力を安定化するスイッチング電源の同期
回路を提供することを目的としている。
In view of such problems, the present invention aims to provide a synchronization circuit for a switching power supply that stabilizes the output of a switching power supply configured with an RCC by making the pulse width of a horizontal synchronization signal variable and wide. There is.

〔問題点を解決するための手段〕[Means for solving problems]

第1図は、本発明のスイッチング電源の同期回路の原理
図であり、スイッチングトランジスタ11とダンパーダ
イオード12と共振用コンデンサ13とを並列に設け、
該並列回路の出力端を同期信号電力供給用トランス20
入力側コイル14の一端に接続したスイッチング回路1
を有してなり、前記同期信号電力供給用トランス2の入
力側コイル14の他端に電源電圧を供給し、CRT表示
装置から検出された水平同期信号を前記スイッチングト
ランジスタ11に供給し、該水平同期信号のパルス幅と
異なったパルス幅のパルスを前記入力側コイル14の両
端に該入力側コイル14のインピーダンスと前記共振用
コンデンサ13の容量に応じて発生させるようにした構
成としている。
FIG. 1 is a principle diagram of a synchronous circuit of a switching power supply according to the present invention, in which a switching transistor 11, a damper diode 12, and a resonant capacitor 13 are provided in parallel.
The output end of the parallel circuit is connected to a synchronous signal power supply transformer 20.
Switching circuit 1 connected to one end of input side coil 14
It supplies a power supply voltage to the other end of the input side coil 14 of the synchronization signal power supply transformer 2, supplies the horizontal synchronization signal detected from the CRT display device to the switching transistor 11, and supplies the horizontal synchronization signal detected from the CRT display device to the switching transistor 11. The configuration is such that a pulse having a pulse width different from the pulse width of the synchronizing signal is generated at both ends of the input side coil 14 according to the impedance of the input side coil 14 and the capacitance of the resonance capacitor 13.

〔作 用〕[For production]

本発明では、第1図に示すように水平同期信号をスイッ
チング回路1に入力させ、その回路内のスイッチングト
ランジスタ11とダンバーダイオード12で波形整形し
た後、同期信号電力供給用トランス2の入力側コイル1
4とこれに直列に接続された共振用コンデンサ13とで
共振させ、入力の水平同期信号パルスのパルス幅と異な
る広い幅のパルスを同じ周期で発生させ、同期信号電力
供給用トランス2の出力側コイル15を経由してReO
2で構成されたスイッチング電源に供給する。
In the present invention, as shown in FIG. 1, a horizontal synchronizing signal is input to a switching circuit 1, and after being waveform-shaped by a switching transistor 11 and a damper diode 12 in the circuit, the input side coil of a transformer 2 for supplying synchronizing signal power is 1
4 and a resonant capacitor 13 connected in series thereto, to generate a pulse with a wide width different from that of the input horizontal synchronizing signal pulse at the same period, and to generate a pulse on the output side of the synchronizing signal power supply transformer 2. ReO via coil 15
2 to a switching power supply consisting of 2.

〔実施例〕〔Example〕

第2図は本発明の一実施例のスイッチング電源の同期回
路のブロック図であるが、第1図及び第4図と同一のも
のは同一の記号で示している。
FIG. 2 is a block diagram of a synchronous circuit of a switching power supply according to an embodiment of the present invention, and the same parts as in FIGS. 1 and 4 are indicated by the same symbols.

また第3図は上記第2図におけるスイッチング回路の主
要部の信号波形を示す図である。
Further, FIG. 3 is a diagram showing signal waveforms of the main parts of the switching circuit in FIG. 2 above.

第2図において、水平同期信号は電力の小さい水平発振
AFC回路21の出力から本発明のスイッチング回路1
に入力され、本回路内の電流調整抵抗16を通り、スイ
ッチングトランジスタ11とダンパーダイオード12で
波形整形される。
In FIG. 2, the horizontal synchronization signal is transferred from the output of the horizontal oscillation AFC circuit 21 with low power to the switching circuit 1 of the present invention.
The signal is input to the circuit, passes through a current adjustment resistor 16 in this circuit, and is waveform-shaped by a switching transistor 11 and a damper diode 12.

水平発振AFC回路21の出力の水平同期信号パルスは
第3図の波形Aに示すようにパルス幅t1が約2us、
周期Tが約20μsのものであり、この狭いパルスを第
2図の同期信号電力供給用トランス2の入力側コイル1
4と共振コンデンサ13からなる直列共振回路で共振さ
せ、第3図の波形B゛に示すようなパルス幅t2が約1
0μ、周期Tが約20p3のパルスに変換され、同期信
号電力供給用トランス2の出力側コイル15にこのパル
スを伝達し、ReO2を経由して装置内の各部の電源と
して供給される。
The horizontal synchronizing signal pulse output from the horizontal oscillation AFC circuit 21 has a pulse width t1 of approximately 2 us, as shown in waveform A in FIG.
The period T is approximately 20 μs, and this narrow pulse is applied to the input coil 1 of the synchronous signal power supply transformer 2 shown in FIG.
4 and a resonant capacitor 13, the pulse width t2 as shown in waveform B in FIG. 3 is approximately 1.
0μ, the period T is converted into a pulse of approximately 20p3, this pulse is transmitted to the output side coil 15 of the synchronizing signal power supply transformer 2, and is supplied as power to each part in the device via ReO2.

即ち本発明のスイッチング電源の同期回路による同期パ
ルスは0N10FF時間が10,113/ 10μs即
ち1であり従来の2 μs/10 pBの0.2に比べ
て安定に動作する。
That is, the synchronous pulse generated by the synchronous circuit of the switching power supply of the present invention has an 0N10FF time of 10,113/10 μs, that is, 1, and operates more stably than the conventional 2 μs/10 pB, which is 0.2.

なおこの同期信号電力供給用パルス幅t2はON時間の
範囲内で共振用コンデンサ13の値を変えることにより
適当な値に調整可能である。
The synchronizing signal power supply pulse width t2 can be adjusted to an appropriate value by changing the value of the resonance capacitor 13 within the ON time range.

〔発明の効果〕〔Effect of the invention〕

以上説明したように本発明によれば、従来のスイッチン
グ電源の同期回路に比べて装置の周波数とスイッチング
電源の周波数を同期させる同期信号のパルス幅を可変に
して広くでき、スイッチング時のノイズが低減されると
ともに、スイッチング電源の温度変動等に対してもパル
ス幅が広いため安定に動作させることができる。
As explained above, according to the present invention, the pulse width of the synchronization signal that synchronizes the frequency of the device and the frequency of the switching power supply can be varied and widened, and noise during switching can be reduced compared to the conventional synchronization circuit of a switching power supply. In addition, since the pulse width is wide, stable operation can be achieved even against temperature fluctuations of the switching power supply.

また同期信号のパルス幅を広くすることによりスイッチ
ング電源の同期引き込みならびに同期保持をより安定に
させることができる。
Further, by widening the pulse width of the synchronization signal, synchronization pull-in and synchronization maintenance of the switching power supply can be made more stable.

さらにノイズが低減されることによりスイッチング電源
に設けていたシールドケースが不要になり、しかも同期
信号パルス発生用の共振用コイルを同期信号電力供給用
トランスと共用していていて部品点数が少なく安価とな
る等の大きな効果が得られる。
Furthermore, the reduction in noise eliminates the need for the shield case provided in switching power supplies, and since the resonant coil for synchronous signal pulse generation is shared with the synchronous signal power supply transformer, there are fewer parts and the cost is lower. Great effects such as:

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明のスイッチング電源の同期回路の原理図
、 第2図は本発明の一実施例を示すブロック図、第3図は
前記第2図におけるスイ・ノチング回路の主要部の信号
波形を示す図、 第4図は従来のスイッチング電源の同期回路のブロック
図である。 図において、1はスイッチング回路、2は同期信号電力
供給用トランス、3はリンギングチョークコンバータ、
11はスイッチングトランジスタ、12はダンパーダイ
オード、13は共振用コンデンサ、半発蛸めIL理図 第1図 $48肩め一尖太ρ刷の7”ローノフ図第2図 2トiどEJpIめスイ・、+ン2イコ呂【−庄1枦(
Pめ信影超1)第3図 9B。スイー/+シフ°・電3原のりIη回S昼図第4
Fig. 1 is a principle diagram of a synchronous circuit of a switching power supply according to the present invention, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a signal waveform of the main part of the switch-noting circuit shown in Fig. 2. FIG. 4 is a block diagram of a synchronous circuit of a conventional switching power supply. In the figure, 1 is a switching circuit, 2 is a synchronous signal power supply transformer, 3 is a ringing choke converter,
11 is a switching transistor, 12 is a damper diode, 13 is a resonant capacitor, half-shot IL diagram Figure 1 $48 Shoulder one point thick rho printing 7" Ronoff diagram Figure 2・,+n2ikoro [-sho1ashi(
Pme Shine super 1) Figure 3 9B. Sweet/+Schif°・Den 3 Hara Nori Iη times S daytime map No. 4
figure

Claims (1)

【特許請求の範囲】 CRT表示装置用のリンギングチョークコンバータ(3
)を使用するスイッチング電源において、スイッチング
トランジスタ(11)とダンパーダイオード(12)と
共振用コンデンサ(13)とを並列に設け、該並列回路
の出力端を同期信号電力供給用トランス(2)の入力側
コイル(14)の一端に接続したスイッチング回路(1
)を有してなり、 前記同期信号電力供給用トランス(2)の入力側コイル
(14)の他端に電源電圧を供給し、CRT表示装置か
ら検出された水平同期信号を前記スイッチングトランジ
スタ(11)に供給し、該水平同期信号のパルス幅と異
なったパルス幅のパルスを前記入力側コイル(14)の
両端に該入力側コイル(14)のインピーダンスと前記
共振用コンデンサ(13)の容量に応じて発生させるよ
うにしたことを特徴とするスイッチング電源の同期回路
[Claims] Ringing choke converter (3) for CRT display device
), a switching transistor (11), a damper diode (12), and a resonant capacitor (13) are provided in parallel, and the output end of the parallel circuit is connected to the input of the synchronous signal power supply transformer (2). A switching circuit (1) connected to one end of the side coil (14)
), which supplies a power supply voltage to the other end of the input side coil (14) of the synchronization signal power supply transformer (2), and transmits the horizontal synchronization signal detected from the CRT display device to the switching transistor (11). ), and a pulse with a pulse width different from that of the horizontal synchronizing signal is applied to both ends of the input coil (14) depending on the impedance of the input coil (14) and the capacitance of the resonance capacitor (13). A synchronous circuit for a switching power supply, characterized in that a switching power supply is generated according to the timing.
JP30781487A 1987-12-04 1987-12-04 Synchronous circuit for switching power source Pending JPH01149577A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30781487A JPH01149577A (en) 1987-12-04 1987-12-04 Synchronous circuit for switching power source

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30781487A JPH01149577A (en) 1987-12-04 1987-12-04 Synchronous circuit for switching power source

Publications (1)

Publication Number Publication Date
JPH01149577A true JPH01149577A (en) 1989-06-12

Family

ID=17973533

Family Applications (1)

Application Number Title Priority Date Filing Date
JP30781487A Pending JPH01149577A (en) 1987-12-04 1987-12-04 Synchronous circuit for switching power source

Country Status (1)

Country Link
JP (1) JPH01149577A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6204616B1 (en) * 1997-06-27 2001-03-20 Funai Electric Co., Ltd. CRT driving circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6204616B1 (en) * 1997-06-27 2001-03-20 Funai Electric Co., Ltd. CRT driving circuit

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