JPS5849079A - Phase controller - Google Patents

Abstract

PURPOSE:To obtain the maximum control output by delaying by the prescribed time a synchronizing signal which operates a discharging circuit which discharges a condenser and resets a blocking oscillator. CONSTITUTION:A pulse (c) having time duration of t2-t0 is formed by the first monostable multivibrator MM1 which is triggered by the fall of a synchronizing signal SY as an input signal, and a pulse (d) having time duration of t3-t2 is formed by the second monostable multivibrator MM2 which is triggered by the rise of the signal SY. The pulse width t3-t2 is the time which can sufficiently discharge completely a condenser C. When the time width of the multivibrator MM1 is suitably set to produce a pulse at 180 deg.C-alpha, a terminal voltage (e) can be obtained at the condenser C, the maximum output waveform of the controlled output reduces to affect the influence of the firing angle alpha, thereby approaching the input voltage to the maximum output voltage of a voltage controller.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field to which the invention pertains The present invention relates to a phase control device for controlling the firing phase of a semiconductor such as a thyristor.

(2) Prior art and its problems When controlling the voltage of a single-phase power supply using a semiconductor thyristor, triac, etc., the phase control that generates the t4 pulse is difficult because the thyristor or triac is ignited. One such device is a circuit using a time constant circuit of a resistor and a capacitor, which operates a negative resistance element such as a UJT (Unijunction Transistor), and uses a tension oscillation circuit.

The configuration of a phase control device consisting of a dirt/4 russ generation circuit using this flexible UJT is kl! Shown in Figure 1.

In Jin's circuit, the resistance R is set at the phase control signal voltage CV.
When the capacitor C is charged through the capacitor C and reaches the peak voltage of the UJTU, the UJTU is turned on. At that moment, current flows through UJTU to resistor R2, and at the same time, current also flows to resistor R3. Resistance Rj
The current flowing through the transistor Q1 is supplied to the transistor Q1, and the transistor Q1 is turned on. Therefore, transistor Q1
A current flows through the primary side of the pulse transformer PT connected to the collector of IF UJTU only at the moment when it is turned on, inducing Noyals on the secondary side.

This Noyalus is used as a dart pulse for a thyristor or tria. Note that R4 is a resistor), Q
jFi synchronous signal sy turns into a ion and capacitor Ct
This is a transistor that discharges electricity.

When this capacitor C starts charging, that is, this f
-) Based on the point where the polarity of the power supply voltage is reversed in case of synchronization of the pulse generation circuit, f: Relationship between the power supply voltage and the terminal voltage of capacitor C when a power supply synchronization signal is adopted 1
Shown in Figure 82.

In other words, Fig. 2(a) shows the power supply voltage, and Fig. 2(b) shows the power supply voltage.
is a periodic signal SY, and a pulse is generated corresponding to the point where the polarity of the power supply voltage is reversed. ′:1 Densa C is the second
Figure (e) shows the terminal voltage at time 1. Charging begins from t j) Until the peak point voltage of UJTU is reached and a dirt pulse is generated, ti is constrained by the time constant of the time constant circuit made of resistor R and capacitor C, which determines the oscillation conditions of UJTU. It takes a certain amount of time -1o.

The firing angle α is an angle corresponding to the sum of this time tl-1· and half of the /intermediate pulse width of the synchronizing signal SY.

When the above-mentioned dart pulse generation circuit is used as a phase control device for sirisk, tria, ri, etc., if the input effective voltage is ■, the maximum output effective voltage is VXl (1 + nod α
), and the voltage control output waveform at maximum capacity is shown in Figure 2 (
As shown in d), there is a problem that the voltage corresponding to the firing angle α is missing, and the maximum output voltage is lower than the input voltage by the amount corresponding to the firing angle α, which is limited by the oscillation conditions of the UJTU. be.

(3) Purpose of the Invention The present invention is for controlling the firing of thyristors, triacs, etc. - A phase control device configured using a tension oscillation circuit in which a negative resistance element is actuated by a time constant circuit of a resistor and a capacitor. The purpose is to provide a phase control device that allows the control output ta to be increased to a value equal to the input (close to full ignition).

(4) Construction of the Invention A delay circuit is provided for delaying a synchronizing signal for a scheduled time to operate a discharge circuit for discharging the capacitor tube of the time constant circuit and resetting the oscillation circuit.

(5) Examples of the invention FIG. 3 shows an embodiment of the present invention.

In the configuration shown in FIG. 3, a monostable multivibrator (hereinafter referred to as "mono-multi") of @1 and ) MHI, b
A delay circuit consisting of mlU is added.

child The operation in a wedge-like configuration will be explained.

Figure 4 shows the waveforms of each part in the configuration of Figure 3.
The figure (&) shows the power supply voltage waveform. FIG. 4(b) shows the same power synchronization signal SY as shown in FIG. 2(b). Using this synchronizing signal sY as an input signal, the first monaural multi-MMJ is triggered by the falling edge of the synchronizing signal sY to generate a pulse waveform having a time width of tl-t. as shown in FIG. 4(,). Furthermore, a second monomulti MM that receives this t4 pulse waveform output as input and is triggered by the falling edge of the t4 waveform output, ? Figure 4 (
Create a pulse having a time width of tl-4, as shown in d). This pulse width ts - tm needs to be long enough to completely discharge the capacitor cl.

In this embodiment, the output/4' pulse of the second monomulti MMZ shown in FIG. Set the time width appropriately to 180°-
If it is generated at α, the terminal voltage waveform of capacitor C will be as shown in Figure 4(,), and the maximum output waveform of the control output will be as shown in Figure 4(f), and vK2(d) as shown in Figure 4(f). It is possible to reduce the influence of the firing angle α seen in the case of the conventional circuit shown in , and to bring the maximum output voltage of the voltage control circuit using a thyristor, trybook, etc. closer to the input terminal. The invention is not limited to the embodiments described above and shown in the drawings, and can be modified in various ways without changing the gist of the invention.

For example, in addition to a mono-multi MMJ or a combination of MMJs, other delay circuits that simply delay the synchronizing signal may also be used.
The negative resistance element I that constitutes the tension oscillation circuit is not a negative resistance element (IUJT) (it may also be a pnpn type switching element, etc.).

(6) The effect of the invention is to increase the electrical margin lIL such as the time constant setting of the time constant circuit for the oscillation condition of the negative resistance element of the tension oscillation circuit, and to increase the maximum control output to the same value as the input value ( You can add t.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the configuration of a conventional device, Figure 2 (a) -
(d) is an operational waveform diagram of each part of the conventional device shown in Figure 1, Figure 3 is a circuit diagram showing the configuration of an embodiment of the present invention, and Figure 4 is an operational waveform diagram of each part in the same embodiment. . MMJ, M)AX...monostable multivibrator (mono multi), U...unijunction transistor (UJT), C...capacitor, RJ~R4...
・Resistor, QJ, QJ...transistor, PT...pulse transformer.

Claims (2)

[Claims] (1) In a phase control device that operates a negative resistance element using a time constant circuit of a resistor and a capacitor and uses a tension oscillation circuit tube, the following step is to operate the discharging circuit that discharges the capacitor and resets the tension oscillation circuit. A phase control device comprising a delay circuit for delaying the synchronization signal period. (2) The phase control device according to claim 1, characterized in that the negative resistance element is an arbitrary transistor. (3) The delay circuit consists of the output of the first monostable multivibrator, which is triggered by a synchronization signal and generates a quarter pulse with a scheduled time width approximately corresponding to the required delay time, and the first monostable multivibrator of Jin. and a second monostable multivibrator that generates seven pulses with a predetermined time width corresponding to the luxury pulse necessary for resetting the triggered oscillation circuit. The phase control device described in .