利用者:加藤勝憲/シリコン制御整流子

Silicon controlled rectifier
	Silicon controlled rectifier
Type	Active
Working principle‍	Ian M. Mackintosh (Bell Laboratories)
Invented	Gordon Hall and Frank W. "Bill" Gutzwiller
First production	General Electric, 1957
Pin configuration	Anode, gate and cathode
Electronic symbol

シリコン制御整流器または半導体制御整流器は、4 層固体電流制御デバイスである。シリコン制御整流器」という名称は、サイリスタの一種であるゼネラル・エレクトリック社の商品名である。4層p-n-p-nスイッチングの原理は、1956年にベル研究所のMoll、Tanenbaum、Goldey、Holonyakによって開発された[1]。シリコン制御スイッチングの実用的なデモンストレーションと、実験結果と一致するデバイスの詳細な理論的挙動は、1958年1月にベル研究所のIan M. Mackintosh博士によって発表された[2][3]。SCRは、Gordon Hallが率いる電力エンジニアのチームによって開発され[4][5][6][7]、1957年にFrank W. "Bill" Gutzwillerによって商品化された。

A silicon controlled rectifier or semiconductor controlled rectifier is a four-layer solid-state current-controlling device. The name "silicon controlled rectifier" is General Electric's trade name for a type of thyristor. The principle of four-layer p–n–p–n switching was developed by Moll, Tanenbaum, Goldey, and Holonyak of Bell Laboratories in 1956.^[1] The practical demonstration of silicon controlled switching and detailed theoretical behavior of a device in agreement with the experimental results was presented by Dr Ian M. Mackintosh of Bell Laboratories in January 1958.^[2]^[3] The SCR was developed by a team of power engineers led by Gordon Hall ^[4] ^[5] ^[6] ^[7] and commercialized by Frank W. "Bill" Gutzwiller in 1957.

シリコン制御整流器とサイリスタを同義語として定義している出典もある[8]が、シリコン制御整流器をサイリスタの適切なサブセットとして定義している出典もある。Bill Gutzwillerによると、「SCR」と「制御整流器」という用語はそれ以前のもので、「サイリスタ」という用語はデバイスの使用法が国際的に広まるにつれて後から適用されたものである[11]。

Some sources define silicon-controlled rectifiers and thyristors as synonymous^[8] while other sources define silicon-controlled rectifiers as a proper subset of the set of thyristors; the latter being devices with at least four layers of alternating n- and p-type material.^[9] According to Bill Gutzwiller, the terms "SCR" and "controlled rectifier" were earlier, and "thyristor" was applied later, as usage of the device spread internationally.^[10]

双方向性（電荷キャリアがどちらの方向にも流れる）のトライアック（TRIAC）とは対照的に、SCRは単方向性デバイス（つまり、電流を一方向にしか流せない）である。SCRは、ゲート電極に正または負の電流を流すことで通常トリガーできるTRIACとは対照的に、ゲートに正電流を流すことでのみ通常トリガーできる。

Modes of operation

There are three modes of operation for an SCR depending upon the biasing given to it:SCRの動作モードは、バイアスのかけ方によって3つある：

順方向阻止モード（オフ状態）
順方向導通モード（オン状態）
逆ブロッキングモード（オフ状態）

順方向阻止モード（オフ状態）

この動作モードでは、アノード（+、pドープ側）には正電圧が与えられ、カソード（-、nドープ側）には負電圧が与えられ、ゲートはゼロ（0）電位、すなわち切断された状態に保たれます。この場合、接合J1とJ3は順方向バイアス、J2は逆方向バイアスで、アノードからカソードへのわずかなリーク電流しか流れない。印加電圧がJ2のブレークオーバー値に達すると、J2はアバランシェ降伏を起こす。このブレークオーバー電圧でJ2は導通し始めますが、ブレークオーバー電圧以下ではJ2は電流に対して非常に高い抵抗を示し、SCRはオフ状態にあると言われています。

In this mode of operation, the anode (+, p-doped side) is given a positive voltage while the cathode (−, n-doped side) is given a negative voltage, keeping the gate at zero (0) potential i.e. disconnected. In this case junction J1and J3 are forward-biased, while J2 is reverse-biased, allowing only a small leakage current from the anode to the cathode. When the applied voltage reaches the breakover value for J2, then J2 undergoes avalanche breakdown. At this breakover voltage J2 starts conducting, but below breakover voltage J2 offers very high resistance to the current and the SCR is said to be in the off state.

順方向導通モード（オン状態）

SCRをブロッキング・モードからコンダクション・モードにするには、2つの方法がある：アノード・カソード間の電圧をブレークオーバー電圧以上に上昇させるか、ゲートに正のパルスを印加する方法である。一旦SCRが導通し始めると、SCRをオン状態に維持するためのゲート電圧は必要なくなります。ゲート電圧の除去時にSCRをオン状態に維持するために必要な最小電流は、ラッチング電流と呼ばれる。

オフにするには2つの方法がある：

Reduce the current through it below a minimum value called the holding current, or
With the gate turned off, short-circuit the anode and cathode momentarily with a push-button switch or transistor across the junction.

Reverse blocking mode

When a negative voltage is applied to the anode and a positive voltage to the cathode, the SCR is in reverse blocking mode, making J1 and J3 reverse biased and J2 forward biased. The device behaves as two diodes connected in series. A small leakage current flows. This is the reverse blocking mode. If the reverse voltage is increased, then at critical breakdown level, called the reverse breakdown voltage (V_BR), an avalanche occurs at J1 and J3 and the reverse current increases rapidly. SCRs are available with reverse blocking capability, which adds to the forward voltage drop because of the need to have a long, low-doped P1 region. Usually, the reverse blocking voltage rating and forward blocking voltage rating are the same. The typical application for a reverse blocking SCR is in current-source inverters.

An SCR incapable of blocking reverse voltage is known as an asymmetrical SCR, abbreviated ASCR. It typically has a reverse breakdown rating in the tens of volts. ASCRs are used where either a reverse conducting diode is applied in parallel (for example, in voltage-source inverters) or where reverse voltage would never occur (for example, in switching power supplies or DC traction choppers).

Asymmetrical SCRs can be fabricated with a reverse conducting diode in the same package. These are known as RCTs, for reverse conducting thyristors.

Thyristor turn-on methods

forward-voltage triggering
gate triggering
dv/dt triggering
thermal triggering
light triggering

Forward-voltage triggering occurs when the anode–cathode forward voltage is increased with the gate circuit opened. This is known as avalanche breakdown, during which junction J2 will break down. At sufficient voltages, the thyristor changes to its on state with low voltage drop and large forward current. In this case, J1 and J3 are already forward-biased.

In order for gate triggering to occur, the thyristor should be in the forward blocking state where the applied voltage is less than the breakdown voltage, otherwise forward-voltage triggering may occur. A single small positive voltage pulse can then be applied between the gate and the cathode. This supplies a single gate current pulse that turns the thyristor onto its on state. In practice, this is the most common method used to trigger a thyristor.

Temperature triggering occurs when the width of depletion region decreases as the temperature is increased. When the SCR is near VPO a very small increase in temperature causes junction J2 to be removed which triggers the device.

Simple SCR circuit

A simple SCR circuit can be illustrated using an AC voltage source connected to a SCR with a resistive load. Without an applied current pulse to the gate of the SCR, the SCR is left in its forward blocking state. This makes the start of conduction of the SCR controllable. The delay angle α, which is the instant the gate current pulse is applied with respect to the instant of natural conduction (ωt = 0), controls the start of conduction. Once the SCR conducts, the SCR does not turn off until the current through the SCR, i_s, becomes negative. i_s stays zero until another gate current pulse is applied and SCR once again begins conducting.^[11]

Applications

SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded. Their operation makes them suitable for use in medium- to high-voltage AC power control applications, such as lamp dimming, power regulators and motor control.

SCRs and similar devices are used for rectification of high-power AC in high-voltage direct current power transmission. They are also used in the control of welding machines, mainly gas tungsten arc welding and similar processes. It is used as an electronic switch in various devices. Early solid-state pinball machines made use of these to control lights, solenoids, and other functions electronically, instead of mechanically, hence the name solid-state.

Other applications include power switching circuits, controlled rectifiers, speed control of DC shunt motors, SCR crowbars, computer logic circuits, timing circuits, and inverters.

Comparison with SCS

A silicon-controlled switch (SCS) behaves nearly the same way as an SCR; but there are a few differences. Unlike an SCR, an SCS switches off when a positive voltage/input current is applied to another anode gate lead. Unlike an SCR, an SCS can be triggered into conduction when a negative voltage/output current is applied to that same lead.

SCSs are useful in practically all circuits that need a switch that turns on/off through two distinct control pulses. This includes power-switching circuits, logic circuits, lamp drivers, and counters.

Compared to TRIACs

A TRIAC resembles an SCR in that both act as electrically controlled switches. Unlike an SCR, a TRIAC can pass current in either direction. Thus, TRIACs are particularly useful for AC applications. TRIACs have three leads: a gate lead and two conducting leads, referred to as MT1 and MT2. If no current/voltage is applied to the gate lead, the TRIAC switches off. On the other hand, if the trigger voltage is applied to the gate lead, the TRIAC switches on.

TRIACs are suitable for light-dimming circuits, phase-control circuits, AC power-switching circuits, AC motor control circuits, etc.

References

^ Moll, J.; Tanenbaum, M.; Goldey, J.; Holonyak, N. (September 1956). “P-N-P-N Transistor Switches” (英語). Proceedings of the IRE 44 (9): 1174–1182. doi:10.1109/jrproc.1956.275172. ISSN 0096-8390.
^ Vasseur, J. P. (2016-06-06) (英語). Properties and Applications of Transistors. Elsevier. ISBN 9781483138886
^ Twist, Jo (2005年4月18日). “Law that has driven digital life” (英語). BBC News 2018年7月27日閲覧。
^ Ward. “The Early History of the Silicon Controlled Rectifier”. p. 6. 12 April 2014閲覧。
^ “Semiconductors: Thyristors and more”. Edison Tech Center. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。
^ “SCR is 50 Years Old”. IEEE Industry Applications Magazine. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。
^ Mungenast, J. E.. “The SCR Revolution”. RF Cafe (General Electric Co.)
^ Christiansen, Donald; Alexander, Charles; Jurgen, Ronald (2005) (英語). Standard Handbook of Electronic Engineering, 5th Edition. Mcgraw-hill. ISBN 9780071384216
^ Dorf, Richard C. (1997-09-26) (英語). The Electrical Engineering Handbook, Second Edition. CRC Press. ISBN 9781420049763
^ Ward. “The Early History of the Silicon Controlled Rectifier”. p. 7. 12 April 2014閲覧。
^ Mohan, Ned (2012). Power Electronics: A First Course. United States: Don Fowley. pp. 230–231. ISBN 978-1-118-07480-0

External links

[[Category:パワーエレクトロニクス]] [[Category:未査読の翻訳があるページ]]

[1] Moll, J.; Tanenbaum, M.; Goldey, J.; Holonyak, N. (September 1956). “P-N-P-N Transistor Switches” (英語). Proceedings of the IRE 44 (9): 1174–1182. doi:10.1109/jrproc.1956.275172. ISSN 0096-8390.

[2] Vasseur, J. P. (2016-06-06) (英語). Properties and Applications of Transistors. Elsevier. ISBN 9781483138886

[3] Twist, Jo (2005年4月18日). “Law that has driven digital life” (英語). BBC News 2018年7月27日閲覧。

[4] Ward. “The Early History of the Silicon Controlled Rectifier”. p. 6. 12 April 2014閲覧。

[5] “Semiconductors: Thyristors and more”. Edison Tech Center. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。

[6] “SCR is 50 Years Old”. IEEE Industry Applications Magazine. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。

[7] Mungenast, J. E.. “The SCR Revolution”. RF Cafe (General Electric Co.)

[8] Christiansen, Donald; Alexander, Charles; Jurgen, Ronald (2005) (英語). Standard Handbook of Electronic Engineering, 5th Edition. Mcgraw-hill. ISBN 9780071384216

[9] Dorf, Richard C. (1997-09-26) (英語). The Electrical Engineering Handbook, Second Edition. CRC Press. ISBN 9781420049763

[10] Ward. “The Early History of the Silicon Controlled Rectifier”. p. 7. 12 April 2014閲覧。

[11] Mohan, Ned (2012). Power Electronics: A First Course. United States: Don Fowley. pp. 230–231. ISBN 978-1-118-07480-0

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