JPS5925418A - Semiconductor switch circuit - Google Patents

Abstract

PURPOSE:To decrease the power consumption of a control circuit without using an auxiliary bilateral npnpn switch, by using an MOSFET which works with a combination of auxiliary MOSFET switches at a Xerox ignition function part. CONSTITUTION:A main siwtch circuit is provided with an AC power supply 1, a load impedance 2 and a bilateral npnpn (TRIAC)3. Then the T2 and G electrodes 3-1 and 3-3 of the TRIAC3 are connected to a zero-cross trigger signal generating circuit 4'. Four enhancement type MOSFET13-16 are used to the circuit 4', and a control circuit consisting of a resistance 11, a DC power supply 10 and a switch 12 is connected to the circuit 4'. The FET13 and 14 are used as auxiliary switches of the TRIAC3, and the FET15 and 16 are actuated by a combination of these auxiliary switches. A trigger signal is supplied to the TRIAC3 at the level near 0V of the power supply 1. Thus the power consumption is decreased for the control circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a bidirectional N1. ' N P N
The present invention relates to a current transformation switch using a switch (hereinafter referred to as 'I'll, l AC). In particular, it relates to a zero-cross current transformation switch that is triggered at the zero volt cross point of a current transformation voltage by a control signal.

Conventional circuits of this type have a main 1” IL that controls the entire load.
- An auxiliary T-IAC'i is connected between the gate electrode of the I-AC and the T2 electrode, and this auxiliary 1
゛l(・The trigger signal to fire IACi is the main I!+,
By detecting the re-terminal voltage of IΔC, the voltage is supplied only near the zero cross of the AC power supply voltage. Therefore, as a power source for the control circuit, the auxiliary 1'lt, J
A container capable of passing a DC current higher than the gate sensitivity of ΔC (several mA) is required.
There was a lot of power loss in the control circuit for making C conductive.

Furthermore, even when there is no conduction, the main '11? , I80 has the disadvantage that a detection current constantly flows through the load in the pressure detection circuit, which further increases power loss. The operation of the conventional circuit shown in FIG. 1 will be explained in detail below. In the figure, 1 is the AC source, 2 is the load impedance, and 3 is the main T-box that supplies power to the load 2 by conducting [AC, 3-1.3-2 and 3-3 are respectively The '111 is also IAC's 11, , IJI 1 and () lightning, pole. 4 is an AC power supply 'i1T; 1. ,
−, l:, the main 'I'll, IA only near the zero crossing of ,
A zero-cross trigger function circuit that supplies all trigger signals to C3, auxiliary 1'll, lAC3, I'U'l'6. P
It consists of an NP transistor 76 and a resistor 8.9. 10 is a direct current source of the control circuit, and 11 is a resistor that limits the ignition force and total flow to the auxiliary T-circuit I. Now, when the switch 12 is in the open state, a current voltage is applied from the source 10 to the gate of the auxiliary +11 IAC and the T1'vl pole, so that the auxiliary T]1. No trigger signal is provided to the IAC.

(jYE'1r main Tl'LLACId is in blocking state)
), IJI, and fIj2, the lightning voltage of AC power supply 1 is blocked at both ends. Therefore, the two resistors 8.9 and the transistor 7 making up the voltage detection circuit
In the emitter, yoke, base, and anode gate of the P TJ T 6, a current is always flowing through the load impedance 2, which is a detection lightning current in which the power supply voltage is divided by a resistor.

Next, the switch 12 can be set to any point on the snowdrift source 1, for example, main T 11. I AC3 (7) 'II' If the switch 12 is closed at any phase of the half-cycle when the two electrodes are positive (1'lX pole is negative), the main TRIA at that point
The voltage across C3, VTI, T2 is large, and the voltage across detection resistor 8, VR8, is zero cross detection city, river VBn (=V person G)
If it seems large, then I) N I) I) The collector and emitter of the transistor 8 are in a conductive state, and the ignition current Fi from the DC priming pressure 10 is passed through the resistor 11 to 1) NP.
) Because it is bypassed by transistor 8, the auxiliary '1゛几lA
C3 is not conductive. Thereafter, in the region near the end of this half cycle, the voltage VR8 across the 8 resistors becomes vus=o-v.
In gn, the bypass PNP) transistor 8 has a power,
Auxiliary 'I'11. An ignition current is supplied to the gate of the IAC. Similarly, the polarity of the AC power source 1 crosses the zero point and reverses, so that the T1 electrode becomes positive (T2, the pole is negative). Initial common voltage state, that is, voltage vats at both ends of R8 resistor is zero cross detection voltage VAG (-VRB)
In the smaller region (VR8”0-VA G ), P
Since tJ 1' 6 is in the cut-off state, the ignition current is supplied to the gate of the auxiliary '1' IAC.

Furthermore, while the switch 12 is closed, the main TItJ A
(? 3 is conductive, V)xs<Vy+n, V person G
Since the PNP transistor and I'UT are always cut off, the ignition current to the auxiliary T-AC3 continues to flow.

If the switch is then opened in any phase of any half-cycle, the ignition current to the auxiliary T-1AC5 will be cut off simultaneously with the opening of the switch 12, but the main T-AC3 will already be open for that half-cycle. Since it enters the conductive state at the ignition signal near the first zero cross, the load current becomes the main 'I'11. -Continuity is maintained until the holding current of the IAC is lowered or lower. By performing the above-described operation, zero-cross power control is performed in which the main AC 3 enters a conducting and blocking state at the zero-cross point of the current power supply 1 by the switch 12 which is opened and closed as desired.

In this way, since the ignition current of the auxiliary RIAC is generally about several mA, the power loss of the control circuit is large, and the DC power supply must be able to tolerate this. The first drawback is that even in the size and specific gravity state, the zero cross detection circuit always has a current flowing through the load.
There were drawbacks such as the need to take into consideration in the design to prevent AC from erroneously firing due to dv/dt.

An object of the present invention is to provide a current transformer switch in which the power loss in the control circuit is minimized, and for this purpose, an MO8 type field effect transistor is used as an auxiliary switch, and the day loss ignition function section is equipped with the above-mentioned Auxiliary MO8F
It is characterized by using another MUS type field effect transistor that operates in combination with E'l' switches.

According to the present invention, since the auxiliary Tll and IAC are not required, the loss of the main P-coupler IAC control circuit is extremely reduced, and furthermore, due to erroneous firing due to dv/dt, the C to the main T-column malfunctions. A cross-flow zero-cross power control circuit is obtained that does not cause any cross-flow.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, in which 1.2.3 shows the AC power supply and load impedance as in the conventional circuit shown in FIG. 2,3-3
are shown at +ll, , T1 and G electrodes, respectively. 4' is the main hook '1 near zero port of the current power supply voltage.
゛几■ Zero-cross trigger (geometric circuit, here four elemental type M
CJS type field effect transistor 13゜14.15,16
"f- is used as an example. Also, 1(+, 11.1
Reference numeral 2 designates a DC 'I'1 source, a current limiting resistor 71j, and a control switch as in the conventional circuit.

The operation of this will be explained in detail below. Now, when the switch 12 is in the open state, there is a control voltage V between the gate and source of the two MO8FE'l' 13 and 14. Since S is not applied, the other two MOSFETs 14 and 1
5, the drain current does not flow regardless of the voltage between the gate and the source. Therefore, the main 'J' [L-IAC3
Since there is no trigger current or current supplied to the terminal, it is in a blocked state. Next, the switch 12 is activated at any point (D point s) of the current transformer power supply 1 (for example, the T2vL pole of the main IILIAc 3 is positive (the Tl electrode is negative).
When it closes at any phase in the half cycle of , the voltage between T2 and 0 of the main V-AC3 at that point: VT 2-G (=
VT t ・T 2 ) is large, temporary [MO8FE'l
'15 Gate I...In the relationship between source voltage: V□B and channel voltage: Vcb, V in V T 2 a
(If 1s,>Voh, 'MO81i'ET
When the switch 12 is closed, it becomes conductive. At this time, no control voltage is applied between the gate and source of M(JSFET 13), and no drain current flows.Therefore, no trigger signal is supplied to TR1AC3, and the circuit is not conducting.

From then on, near zero volts near the end of this half cycle,
Gate-source voltage V of MoS2"E'l' 15
os7 in relation to the channel voltage Vcb.
T2G* VO2<'1'OIl Tonal? [Pressure area Mteim Because there is a high resistance between the drain and source of MO8FET15, the DC voltage 10 is almost the same as MO8F
It is applied between the gate and source of ET13. Here, the DC voltage is 10 M (JSFET 13 O, 1: and 14 Nochia, *L W, voltage V.).

If you set it large enough, the flow will be M (from D to S of JSFEi'l 3 and further M) to gate 1 of T-IAC3.
S-+J) of O8FET 14 as a channel current, resulting in conduction. Similarly, the polarity of the current power supply crosses the zero point and turns, Ts! In the initial voltage state where the pole is positive (the Il13 electrode is negative), M V.5<Vc
In the voltage region where M(JSFE'l'16 has a high resistance between the drain and source, 'J'lAC
The gate current of 3 is supplied as a channel current to MO8Ii'l bow T14's 1]→S and further to M (JSIi'E'r13's S→J), and becomes conductive.After that, the switch 12 is closed and the two During this period, 1itRIAC3 is conductive, and the gate-source voltage of T15 and T16 is sufficiently small compared to the channel voltage (Vos<<
Vc It ), so there is high resistance between the drain and source of the same F and 1 bow Ill! J DC feeding control 141 (, pressure 11
M (JS circle (1') including the vicinity of the zero cross, HJ is continuously applied between the gates and sources of 13 and 14, and T
A state in which the ignition current flows to AC3 is maintained. If the switch is then opened at any phase of any half cycle, the gate-to-source voltage to MOSFETs 13 and 14 will be cut off at the time of opening of switch 12, but TTLIAC3 will already be open for that half cycle. Since it enters a conductive state at the ignition signal near the first zero cross,
At the end of a quarter cycle, the load flow is T
Continuity is maintained until the holding current of C is lower than or equal to the blocking state. By performing the above operations, you can open or open the
With the switch 12 closed, Tit and IAC 3 perform AC zero-cross power control in which they enter a conducting and blocking state at the zero-crossing point of the transformer power supply 1.

As can be seen from the above description of the operation of the embodiment of the present invention, the switch that supplies the entire ignition current to the 1゛IAC is N1JN.
Auxiliary TR, IΔ, C which is a bidirectional zyristor of PN
A current I composed of field effect transistors instead of
2) Since the switching circuit is used, the charging Rt of 1p total capacity is required.
tj, the flow will occur 1■ (I V /d will be ignited incorrectly. Also, ・Insulated type M (
J S F I', T's insulated gate using gold 1i1
, Since the circuit is configured to detect pressure under the channel between the gate and source of the furnace 1, the power loss in the control circuit is extremely small.In addition, the power loss in the control circuit is extremely small, and in addition, the current is constantly flowing through the zero cross detection circuit through the load when the switch is opened. The advantage is that no current flows in this example. Especially low? Since IT and flow control are possible, there are great advantages in applications such as direct control using the output of integrated circuits such as i"l' L.In addition, to IUs
Semiconductor elements other than FETs can also be used as long as they have the control function described above, and the circuit design can be changed as needed.

Figure 1 - Conventional zero-cross AC power control 1 circuit diagram, Figure 2 is an uninvented zero-cross AC power control 10
FIG. 2 is a switch circuit diagram of one embodiment of a one-way switch;

Claims (1)

[Claims] In an AC switch circuit having an N P N I3N element and a trigger means for the element, the trigger means is constituted by a plurality of semiconductor transistor groups controlled by a DC power supply and a switch means connected to the DC power supply.
tJ plural semiconductor transistor groups are Ail N, IF
1 connected between one electrode of the Nr'N element and the indexing pin
- A semiconductor switch circuit characterized by including a pair of transistors as a current path for a trigger signal, and a transistor for opening/closing control of the pair of transistors.