JPS6040267B2 - Soft start device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soft start device that improves fluctuations in soft start time.

For example, as a conventional soft start device,
There is one shown in Japanese Patent No. 131635.

This can prevent overcurrent from flowing to the load during startup and can provide good results. Furthermore, in this case, the voltage supplied to the time constant circuit that influences the soft start time is almost constant, so the soft start time is almost constant.
However, if the phase control device is installed remotely from the load in a light control device, etc., it is disadvantageous in terms of wiring to obtain the voltage of the time constant circuit from the input side of the phase control device. You can get it from the output of

In this case, since the output of the phase control device may vary between 0 and 100%, the time required to charge the capacitor of the time constant circuit to a predetermined value changes significantly, and as a result, the soft start time fluctuates. There was a problem. It is also conceivable to make the output of the phase control device a constant voltage using a constant voltage element or the like and supply this constant voltage output to a time constant circuit, but this has the disadvantage of being expensive. The present invention has been made in order to solve the above problem, and in a device in which the voltage of the time constant circuit of a soft start device is obtained from the output of a phase control device, the output of the phase control device is 0 to 100.
It is an object of the present invention to provide a soft start device in which the soft start time hardly changes even if the soft start time changes between % and %.

The present invention focuses on the fact that a phase-controlled voltage has a sudden and slow rise, and provides a differentiating circuit that generates a pulse-like output by being supplied with a voltage having this rise. By supplying the output of 1 to the capacitor of the time constant circuit, the time delay caused by the voltage drop due to phase control is compensated for, thereby improving the fluctuation of the soft start time.

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

Reference numeral 1 denotes a power source that outputs a voltage that periodically passes through the zero point, such as a commercial AC power source.

Reference numeral 2 denotes a phase control device, which is composed of triacs, thyristors connected in anti-parallel, etc., such as a distribution board (not shown).

) etc. Since such a control device for the phase control device 2 is well known, illustration and description thereof will be omitted. 3 is a load device to which the output of the phase control device 2 is supplied via a rectifier 4.

This load device 3 consists of, for example, a transistor inverter 5 and a poppy light lamp 6 energized by the output of the inverter 5, and is a lighting device (not shown) provided remotely from the phase control device 2. will be stored in.
Since the inverter 5 is well known, the explanation will be omitted, but the starting resistors R, , R2 are transistors Tr, Tr2.
is set to a value that can supply only the base current for class A operation. Further, the front fluorescent lamp 6 has its electrodes f,
, f2 are preheated by the output of the output transformer T. Reference numeral 7 denotes an inductor connected in series to the input terminal of the transistor inverter 5, which suppresses high frequency components of the input current of the inverter 5.

8 is a transistor Tr of the transistor inverter 5;
, , is a base current source of Tr2, and is formed by rectifying and smoothing a part of the output of the inverter 5.

The positive terminal of this base current source 8 is connected to a thyristor 9.
The anode/cathode of is connected to the bases of the transistors Tr, Tr2 via resistors 10 and 11, and the load terminal is connected to the emitter of each of the transistors Tr, Tr2. By being supplied with a base current from this base current source 8, the transistor T
r, , T perform a predetermined switching operation. An integrating circuit consisting of a resistor 12 and a capacitor 13 is connected between the anode and cathode of the thyristor 9.
This integrating circuit is supplied with a voltage corresponding to the output of the phase control device 2, that is, the output of the base current source 8, and charges the capacitor 13.

A connection point between the resistor 12 and the capacitor 13 is connected to the gate of the thyristor 9. therefore,
The conduction of the syringe 9 is controlled by the voltage across the capacitor 3. 14 is a resistor for discharging the capacitor 13.

Next, 15 is a differentiating circuit, which is connected between the output terminals of the rectifying device 4 via the inductor 7, and is supplied with the output of the phase control device 2. As is well known, the differentiating circuit 15 generates a pulse-like output when a rapidly rising waveform is applied thereto. The output of this differentiating circuit 15 is, for example, a diode 16.
and the capacitor 3 of the integrating circuit via the resistor 17
and charges this capacitor 13. It should be noted that this differentiating circuit 15 generates almost no output when the output of the phase control device 2 does not have a sharp rising part, that is, when the output is 100%. The action will be explained below.

First, a case will be described when the output of the phase control device 2 is 100%. The transistor inverter 5 of the load device 3 has a starting resistance R, ? By supplying the base current through R2, one of the transistors Tr, Tr2 is turned on and started. At this time, the output of the inverter 5 is below a predetermined value because the base currents of the transistors Tr, , Ttr2 are insufficient. Therefore, the poppy lamp 6 cannot be lit, and only the electrodes f, f2 are preheated. When the inverter 5 starts, the base current source 8 also outputs, and the capacitor 13 of the integrating circuit is connected to the positive terminal of the base current source 8, the resistor 12, the capacitor 3, and the resistor 10.
Alternatively, charging begins in the closed circuit of the negative terminal of the base-emitter-base current source 8 of the transistor Tr 11 or Tr2. At this time, since the phase control output of the differentiating circuit 15 does not have a sharp rising edge, it hardly generates an output, so that the differentiating circuit 15 does not contribute to charging the capacitor 3. When the charging voltage of the capacitor 3 reaches a predetermined value, the thyristor 9 is turned on, and the base current source 8 flows from the thyristor 9 to the resistor 10 or 11 to the base emitter base current of the transistor Tr or Tr2. A current flows through the circuit of source 8, and transistors Tr, Tr
2 will be supplied with sufficient base current. As a result, a predetermined voltage is supplied to the transistor inverter 5 of the load device 3, and the inverter 5 generates a predetermined output. By applying this inverter output,
In fact, the light lamp 6 lights up. Therefore, the poppy light lamp 6, which is a part of the load device 3 of this embodiment, is started by applying a high voltage after the electrodes f, f2 are sufficiently preheated, so that the life of the poppy light lamp 6 is not impaired. It is something. In this case, the soft start time is set to around 1.9 seconds, for example. Next, the output of the phase control device is 10
We will discuss below 0%, that is, during dimming.

The transistor inverter 5 of the load device 3 is the starting resistor R.
, , R2 supplies the base current of the transistors Tr, Tr2 to start, and a phase-controlled voltage is supplied to generate an output. However, during this dimming, 10
Since the input to the transistor inverter 5 is reduced compared to when it is 0%, the output of the base current source 8 is also small. Therefore, it takes a long time to charge the capacitor 3 in the integrating circuit by the output of the base current source 8, and as a result, the soft start time also becomes long. However, in the present invention, a differentiating circuit 15 is provided, and this differentiating circuit 15 generates a pulse-like output at the rising edge of the phase control output, and this output causes the capacitor 13 to be connected to the diode 16 - resistor 17 - capacitor 1.
3 - Resistor 10 or 11 - Transistor Tr, or T
Since charging is performed through the base emitter of r2, the shortfall in charging by the base current source 8 is compensated for. As a result, the time it takes for the charging voltage of the capacitor 13 to reach the predetermined value is almost the same as when it is 100%, and therefore the soft start time hardly changes. Note that since the output of the differentiating circuit 15 changes depending on the conduction phase of the phase control device 2, that is, the instantaneous voltage value at the rising edge, the soft start time cannot always be kept constant.
It is clear that the fluctuation of the soft start time can be greatly improved compared to the case where the capacitor 13 is simply charged in accordance with the phase control output without providing a phase control output. FIG. 2 shows another embodiment of the invention.

The same parts as in FIG. 1 are given the same reference numerals, and their explanation will be omitted. The transistor Tr. of the transistor inverter 5 of the load device 3 in this embodiment. , Tr2's base currents are directly supplied from the output of the phase control device 2. That is, the positive output terminal of the rectifier 4 is connected to the base of the transistor Tr through resistors R3 and R4, and to the base of the transistor Tr2 through resistors R3 and R5, respectively. A series circuit of a diode 20 and a capacitor 21 is provided between the non-power supply terminal of the resistor R3 and the negative output terminal of the rectifier 4. That is, in this embodiment, by flowing a charging current through the capacitor 21' at the time of starting, the base current of the transistors Tr, Tr2 is reduced, thereby reducing the power supplied to the transistor inverter 5, which is a part of the load device 3. It is something to control.
In this embodiment, the resistor R3 also serves as the resistor of the integrating circuit. Further, the differentiating circuit 15 is constructed in the same manner as in FIG. 1, and charges the capacitor 21 via a diode 16 and a resistor 17. 22 is a discharge resistor.

When the charging voltage of the capacitor 3 reaches a predetermined value, the transistors Tr, Tr2 have resistors R3, R4, R5.
The rated base current is supplied through the It is easy to understand that the same effects as in the first illustrated embodiment can be obtained in this embodiment as well. Note that the present invention is not limited to the above embodiments.

For example, the load device may include a transistor inverter, a poppy lamp, a light lamp, or a light bulb, etc.
In short, the effects of the present invention can be obtained if a soft start is required at startup and the power is adjusted by phase control. Alternatively, the capacitor of the integrating circuit may control the constant oscillation circuit, and the power supplied to the load device may be controlled by a switching element that operates according to the output of the constant oscillation circuit. Furthermore, the differentiating circuit is not limited to that of the above embodiment, and
It is also possible to supply the output of the differentiating circuit directly to the capacitor without passing through the resistor. Furthermore, the input to the load device may be directly controlled according to the charging voltage value of the capacitor of the integrating circuit. As detailed above, the present invention
In devices that supply the output of the phase control device to a load device, the capacitor of the integrating circuit, which affects the soft start time, is charged with a voltage according to the output of the phase control device, and at the same time Since charging is performed using the output of the differentiating circuit that generates a pulse-like output, it is possible to provide a soft start device that can significantly improve fluctuations in soft start time without increasing the number of wiring lines and at low cost.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are circuit diagrams each showing an embodiment of the present invention. 1...Power supply, 2...Phase control device, 3
... Load device, 5 ... Transistor inverter, 6 ... Poppy, light lamp, 13, 21 ...
Capacitor, 15... Differential circuit. O diagram O 2 diagram

Claims (1)

[Claims] 1. A power source that outputs a voltage that periodically passes through a zero point, and a phase control device that obtains a phase control output from the output of this power source,
a load device supplied with the output of the phase control device; and an integrating circuit provided with a capacitor that soft-starts the load device until the charging voltage reaches a predetermined value and supplied with a voltage according to the output of the phase control device. , a differentiating circuit that is supplied with the output of the phase control device and supplies the output to a capacitor of the integrating circuit. 2. The soft start device according to claim 1, wherein the load device includes a transistor inverter and a discharge lamp. 3. The soft start device according to claim 2, wherein the transistor inverter reduces the base current of the transistor during the soft start period and operates in class A mode. 4. The soft start device according to claim 3, wherein the integrating circuit is supplied with the output of the transistor inverter. 5. The software according to any one of claims 1 to 4, wherein the capacitor of the integrating circuit controls the power supplied to the load device by controlling a semiconductor switching element. Starting device.