JPH04156270A - Dc regulated power supply unit - Google Patents

Abstract

PURPOSE:To generate a regulated DC voltage by providing a modulating means which outputs a frequency- and amplitude-modulated signal and a transferring means which extracts information indicating the difference between an output and set voltages and another information indicating whether or not the output voltage exceeds a comparison voltage and sends the extracted information to a control circuit. CONSTITUTION:A modulating means 10 outputs a signal VC which is modulated in frequency by means of the output of an excessive output detector 7 and in amplitude by means of the output of a difference detector 6. Namely, the amplitude of the signal VC is modulated in accordance with the difference between an output and set voltages and the frequency of the signal VC is changed depending upon whether or not the output voltage exceeds a comparison voltage. Transferring means 12 and 13 receive the signal VC through an insulating transformer 11 and send information indicating the difference between the output and set voltages and another information indicating whether or not the output voltage exceeds the comparison voltage to a control circuit 4 after extracting the information from the signal VC. Therefore, a regulated output voltage can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a power supply device that generates a stabilized DC voltage.

<Prior art> Fig. 3 shows a conventional DC stabilization source device.The stabilized AC voltage e1 applied to the terminal P1 is connected to the rectifier smoothing port F#1.
1, it is converted into a DC voltage. Since the transistor 5 that acts as a switching element is connected to the primary side of the main transformer 2, the DC voltage of the rectifier smoothing port F#11 is switched and applied to the primary winding of the main transformer 2. . The AC voltage generated on the secondary side of the main transformer 2 is converted into a DC voltage Vo by the rectifier and smoothing circuit 3, and the output terminal P
2. It is applied to load 2 from P3. This output voltage ν0
is introduced into the feedback circuit 17, where the set voltage V, is introduced. ,
compared to Feedback DffR174, t, deviation (Vo-
V, 81) t: Outputs the corresponding AC signal VA and returns it to the control circuit 4 via the isolation transformer 18. The control circuit 4 reads the deviation from this AC signal VA and determines that the deviation is "O".
Since the transistor 5 is switched so that the output voltage Vo=Vref, the system is stabilized. That is, the stabilized AC voltage e1 becomes the DC voltage vO according to the set voltage vref.

On the other hand, if the setting voltage vref to be applied to the feedback circuit 17 is incorrectly set, or if the lead wire connecting terminal P2 and the feedback circuit 17 (this lead wire may be long) is broken, excessive output will occur and this will cause There is a possibility that the voltage ν0 at the terminal P2 is applied to the load 2. In order to prevent such a situation, the voltage ν0 at the terminal P2 is also led to the comparator 19 and compared to the comparator voltage 1p.Then, the output voltage νO is , , ), the comparator 19 applies the AC signal VB to the control circuit 4 via the isolation transformer 20. Upon receiving this signal VB, the control circuit 4 learns that an excessive output has been applied to the load 2, and
Stop output operation.

<Problems to be Solved by the Invention> The conventional DC stabilized power supply device as described above requires two isolation transformers 18 and 20 in addition to the main transformer 2. I will add an explanation to this.

in general,! [The current stabilizing power supply device needs to isolate the primary side circuit and the secondary side circuit of the main transformer 2 in terms of DC so that a stable DC voltage can be applied to the load 2. Therefore, in order to transmit signals from the feedback circuit F#117 and comparator 19 belonging to the secondary side circuit to the control circuit 4 belonging to the primary side circuit, it is necessary to pass through isolation transformers 18 and 20, respectively. .

The isolation transformers 18 and 20 are generally large in shape, which hinders miniaturization of the power supply device.

An object of the present invention is to share information on the deviation between the output voltage and the set voltage and information on whether the output voltage exceeds the comparator voltage by sharing one isolation transformer with the main transformer. An object of the present invention is to provide a DC stabilized power supply device that can transmit power to the next side.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a control circuit in which a primary side circuit is provided with a switching element connected to the primary winding of a main transformer to which a stabilized DC voltage is applied. In a device that extracts a stabilized output voltage from a rectifying and smoothing circuit connected to the secondary winding of the main transformer by controlling the output voltage, the device includes a deviation detector that outputs a signal according to the deviation between the output voltage and the set voltage; An excessive output detector outputs a signal when the output voltage exceeds a comparator voltage, and the output of this excessive output detector and a deviation detector are introduced, and the frequency is modulated by the output of the excessive output detector, and the deviation detection Signal whose amplitude is modulated by the output of the device [νC]
a modulation means (10) for outputting
Information indicating the deviation between the output voltage and the set voltage and information indicating whether the output voltage exceeds the comparator voltage are extracted from the output signal fVc) of the modulation means introduced via the control circuit. The transfer means (12, 13) for sending the data to

Effect> The modulating means outputs a signal (VC) whose frequency is modulated by the output of the excessive output detector and whose amplitude is modulated by the output of the deviation detector. That is, the amplitude of this signal [VC] is modulated according to the deviation between the output voltage and the set voltage, and the frequency of this signal (VC) changes depending on whether or not the output voltage exceeds the comparator voltage. do.

The transfer means introduces a signal (VC) through an isolation transformer, and from this signal (νC), information indicating the deviation between the output voltage and the set voltage and whether the output voltage matches the comparator voltage or not is obtained. It is possible to extract information indicating

<Example> Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a diagram showing a configuration example of a DC stabilized power supply device according to the present invention, and FIG. 2 is a diagram showing the first illustration! It is a time chart of signals of each part.

In FIG. 1, the connection configuration of the input/output terminals P1 to P3, the rectifier and smoothing circuit 1.3, the main transformer 2, the control circuit 4, the transistor 5, and the load 2 is the same as the device in FIG. 3. Therefore, these explanations will be omitted.

Below, we will focus on the interesting parts.

The deviation detector 6 receives the output voltage Vo at the output terminal 22 and the set voltage Vref, and outputs a signal according to the deviation (Vo V,8()) between these two voltages.

Such a deviation detector 6 can be configured with, for example, a difference calculator (not shown) and an integrator (not shown) that integrates the output of the difference calculator.

That is, the difference calculator calculates (Vo V ref ).

Then, this deviation (ν”ref) is integrated by an integrator.

Therefore, the output of the integrator changes in a direction depending on the polarity of this deviation signal. In the device shown in FIG. 1, the output voltage vO is controlled in such a direction that the change in the output of the integrator (output of the deviation detector 6) stops, so that the output of the integrator eventually becomes constant.

That is, νo=V.

ref Excessive output detector 7 compares output voltage ν0 with voltage V. The magnitude of Imp is compared, and when the output voltage vO exceeds the comparator voltage c, p, a signal is output.

For example, when Vo<V, an OI4 level signal is output, and when V<Vo, an old (J level signal is output).

The modulating means 10 introduces the outputs of the excessive output detector 7 and the deviation detector 6, and generates a signal VC whose frequency is modulated by the output of the excessive output detector 7 and whose amplitude is modulated by the output of the deviation detector 6. Output. Such modulation means 10 is
It can be configured by an oscillator 9 and a modulator 8.

The oscillator 9 has a function of changing its oscillation frequency in accordance with the signal from the excessive output detector 7. For example, when the output of the excessive output detector 7 is at the level of 1, it outputs frequency 11, and when it is at the level of HJGH, it outputs frequency 12.

The modulator 9 uses the output signal of the oscillator 9 as a carrier wave, and modulates the amplitude of this carrier wave using the output signal (low frequency) of the deviation detector 6. Therefore, it is possible to output a signal νC whose frequency is modulated by the output of the excessive output detector 7 and whose amplitude is modulated by the output of the deviation detector 6.

The modulator 8 and oscillator 9 having such functions can be easily constructed by those skilled in the art, so a detailed explanation thereof will be omitted.

The isolation transformer 11 converts this signal VC into one of the main transformers 2.
It is added to the demodulator 12 and frequency discriminator 13, which are the next circuits.

The demodulator 12 extracts an amplitude modulated signal that is an envelope waveform of the signal VC. That is, from the signal VC, the output voltage V.

Information indicating the deviation between the set voltage vref and the set voltage vref is extracted.

The frequency discriminator 13 outputs a signal according to the frequency of the carrier wave from the signal VC. That is, the output voltage ν0 is the comparator voltage ■. Information indicating whether lp has been exceeded is extracted.

Control diagram F! @4 so that the output signal of the demodulator 12 is constant (so that the output signal of the deviation detector 6 is constant)
Switching control of transistor 5 is performed.

In addition, the control diagram N4 shows the output voltage V from the frequency discriminator 13.
When a signal indicating that o exceeds the comparator voltage vC1p is output, the transistor 5 is turned off and the output voltage Vo is forced to Ov.

The operation of the apparatus shown in FIG. 1 configured as above will be explained.

As shown in Figure 2, before time ■1, vo〈■C1,l
), therefore, the output of the excessive output detector 7 is
tOW (see Figure 2 (1)), at this time the oscillation H9
It is assumed that the frequency f1 is outputted.

On the other hand, the deviation detector 6 detects the output voltage Vo and the set voltage vre.
It is assumed that a signal corresponding to the deviation of f is output, and the output transition is as shown in FIG. 2 (3).

The modulator 8 uses the signal shown in FIG. 2 (2) as a carrier wave and modulates the amplitude of this carrier wave with the signal shown in FIG. 2 (3), so it outputs the signal VC shown in FIG. 2 (4).

The demodulator 12 introduces the signal VC via the isolation transformer 11 and extracts an amplitude modulated signal that is an envelope waveform of the signal VC. That is, the output signal of the deviation detector 6 is taken out (see FIG. 2 (5)).

The frequency discriminator 13 outputs a signal according to the frequency of the carrier wave from the signal VC. That is, before time 1, the excessive output detector 7 detects the output bell signal (see FIG. 2 (6) l').

The control circuit 4 controls the switching of the transistor 5 so that the output signal of the demodulator 12 is constant (see FIG. 2 (7)).
)#re), as a result, the output voltage Vo=Vref.

Next, as shown in Fig. 2, it is assumed that for some reason at time 1, V, , < Vo (excessive output has occurred). Therefore, the output of the excessive output detector 7 is GH level (see Fig. 2 (1)), and the frequency of the oscillator 9 becomes f.
2 (see FIG. 2 (2)), and as a result, the output VC of the modulator 8 becomes as shown in FIG. 2 (4).

Therefore, the frequency discriminator 13, as shown in FIG. 2 (6),
Becomes IGH. The control circuit 4 learns that an excessive output has occurred because the output of the frequency discriminator 13 has reached the old GH level, and turns off the transistor 5 (stops the switching operation), that is, turns off the main transformer 2. Since the operation is stopped, the output voltage vO becomes OV.

As a result, after time 1, the waveforms shown in FIG. 2 change as shown by solid lines (the dotted lines are drawn to facilitate understanding of the operation of the present invention).

In addition, although the case of overvoltage was shown as the excessive output detector 7 in the above description, it may operate in the case of overcurrent.

In addition, although Fig. 1 shows an example in which the rectifying and smoothing circuit 1.3 is composed of one diode and a capacitor, it is also possible to perform full-wave rectification using multiple diodes or use a choke coil. Flies).

In addition, as shown in Fig. 4, in the case of a power supply with multiple outputs (for example, ζf5v and 24v), the excessive output voltage on the 24 V side is monitored by the 5ν output detector 7, and the
In this case, the information number detected by the frequency discriminator 13 is the information number at the 24V@ source. This is information indicating the presence or absence of excessive output, and the output of the frequency discriminator 13 is added to the 24V side control circuit 4°. On the other hand, the information detected by the frequency discriminator 13' is SV
This is information indicating the presence or absence of excessive output in the t source, and the output of the frequency discriminator 13' is applied to the 5V@ control circuit 4.

Furthermore, in the above description, the signal output from the excessive output detector 7 is a binary signal of either HIGH or LOW, but a plurality of information may be transmitted by outputting a plurality of levels.

Furthermore, when the excessive output detector 7 operates, the transistor 5
Switching stops and the operation of the entire device stops as shown in Fig. 1. To release this stopped state, for example, by applying the control circuit 4G reset/gamma signal, the switching operation is started again. can be done.

Effects of the Present Invention> As described above, according to the present invention, the same function as the conventional device can be achieved with only one isolation transformer.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the configuration of a DC stabilized power supply device according to the present invention, Fig. 2 is a time chart of signals of each part of the device shown in Fig. 1, Fig. 3 is a diagram showing a conventional example, and Fig. 4 is a diagram of the present invention. It is a figure which shows another Example of invention. 1.3... Rectifier and smoothing circuit, 2... Main transformer, 4...
... Control circuit, 5... Transistor, 6... Deviation detector, 7... Excessive output detector, 10... Modulation means,
11... Isolation transformer, 12... Demodulator, 13...
・Frequency valve MIJ device. Figure 3: Ward 4

Claims (1)

[Claims] By controlling the switching element connected to the primary winding of the main transformer to which the stabilized DC voltage is applied by a control circuit provided in the primary circuit, In a device that extracts a stabilized output voltage from a connected rectifier and smoothing circuit, there is a deviation detector that outputs a signal according to the deviation between the output voltage and the set voltage, and an excessive detector that outputs a signal when the output voltage exceeds the comparator voltage. A signal (VC) in which the output of an output detector, this excessive output detector, and a deviation detector is introduced, the frequency is modulated by the output of the excessive output detector, and the amplitude is modulated by the output of the deviation detector.
a modulation means (10) for outputting
Information indicating the deviation between the output voltage and the set voltage and information indicating whether the output voltage exceeds the comparator voltage are extracted from the output signal (VC) of the modulation means introduced through the control A DC stabilized power supply device comprising transfer means (12, 13) for sending data to the circuit.