JPS5814638A - Insulated transmitting circuit of driving control signal - Google Patents

Abstract

PURPOSE:To control a device in a system to be controlled by a control system at an insulator side, by obtaining a differential pulse by differentiating a control pulse signal and multiplexing the differential pulse to transmit it via a pulse transformer. CONSTITUTION:A control system block 40P is connected to a system block 40S to be controlled via a pulse transformer 45. In the block 40P, a signal having a pulse duration corresponding to the degree of control is differentiated by differentiating circuits 43A and 43B, respectively. These differential pulses are added and synthesized with each other by an adder 44 with different amplitudes. Thus a multiplexed differential pulse is obtained and transmitted to the block 40S via the transformer 45. On the other hand, the block 40S discriminates the differential pulse signals through a signal separating circuit 46 and in accordance with the amplitude and then reproduces a control signal based on each differential pulse. In such a way, the control system can be insulated from the system to be controlled with a pulse transformer, and the system to be controlled at the earth side can be controlled by the insulated control system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides insulation between a control system and a controlled system using a pulse transformer, and also multiplexes a plurality of control signals from the control system and insulates them via the pulse transformer. The present invention relates to an isolated drive control signal transmission circuit configured to transmit signals to a control system and perform multiple control.

Generally, in various electronic devices, it is necessary to insulate external connection terminals and various adjustment parts in order to prevent electric shock accidents for users. For example, in a television receiver, as shown in FIG. 1, the tuner block 2 that handles the received signal from the antenna 1, the intermediate frequency block 3, the video signal system block 4, the audio signal system block 5, etc. are on the insulated side. A power supply block 6 for supplying power to various blocks, a cathode ray tube 7, a high voltage block 8 for supplying driving power to the cathode ray tube 7, and the like are disposed on the ground side. Therefore, the control system must be insulated in order to control the drive of the power source 6, high-voltage block, etc. on the ground side. However, in general, the power supply block 6, high voltage block 5, etc. each have multiple outputs, so if each output is isolated for each control system, multiple large-capacity transformers are used for this isolation. Therefore, the present invention aims at transmitting differential pulses obtained by differentiating a plurality of control pulse signals through a pulse transformer in a multiplexed state. This is an isolated drive control with a new configuration that uses a small-capacity pulse transformer to isolate the control system and controlled system, and allows the control system on the insulated side to control multiple operations of the controlled system. It provides a signal transmission circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing one embodiment.

In the embodiment shown in FIG. 2, the present invention is applied to a two-output isolated power supply device in which two switching regulators 20 and 30 are arranged in parallel.

In this embodiment, in the first switching regulator 20, an oscillator 21 oscillates when input DC power is supplied to the DC power input terminal 10, and the oscillation output of the oscillator 21 causes the primary side of the transformer 22 to The switching transistor 23 connected to the coil 22P operates, and the generated voltage obtained in the secondary coil 228 of the transformer 22 by the switching operation of the switching transistor 23 is outputted from the first output terminal 11 via the rectifier circuit 24. It is configured as follows. Similarly, the second switching regulator 30 also operates at the power input terminal 10.
A transformer 32 including a primary coil 32P connected to the rectifier circuit 34 and a secondary coil 32S connected to the rectifier circuit 34;
It consists of a switching transistor 33 connected to the primary coil 33PK and an oscillator 31, and a rectifier circuit 34 rectifies the generated voltage obtained in the secondary coil 32S of the transformer 32 by the switching operation of the switching transistor 33. In this embodiment, each of the oscillators 21 and 31 of each of the switching regulators 20 and 30 is configured to output from the output terminal 12 of the switching regulator 20, 30. Each control signal provided by
The drive is controlled as shown in □.

That is, the output of the first switching regulator 20 is supplied to the first pulse width modulator 42A, and the output of the second switching regulator 30 is supplied to the second pulse width modulator 42B. ing.

Each of the pulse width modulators 42A and 42B is connected to a switching regulator 2ot for a reference pulse width signal as shown in FIG. 3A from the reference pulse signal generator 41.
(according to the output voltage from 30) (by performing pulse width modulation,
Each of the control signals indicating the control amount with the pulse widths T A and T n is formed.Then, each of the above) (the control obtained by the pulse width modulators 42A and 42B) (the pulse signal 75
are supplied to the signal adder 44 via differentiating circuits 43A and 43B, respectively.

Here, the first differentiating circuit 43A differentiates the first control pulse signal from the first pulse width modulator 42A as shown in FIG. A positive differential pulse with an amplitude of Lo is formed in a large part, and a positive differential pulse with an amplitude of Lo is formed in a large part, and a positive differential pulse with an amplitude of Lo is formed in a large part. In addition, the second differentiation circuit 43B differentiates the second control pulse signal as shown in the third diagram from the second pulse modulator 42B. Then, in the rising portion of the control pulse signal, a positive differential pulse with an amplitude of Lo is formed, and in the falling portion of the cloth control pulse signal, a positive differential pulse with an amplitude of L2 is formed. , to obtain a positive differential pulse signal as shown in FIG. 3E. In addition, in this example,
The amplitude of each of the above differential pulses is set to L, )Lo>I, 2. Then, the differential pulse signals of the differentiating circuits 43A, 43Bd-, etc. are combined by a signal adder 44 by sicarotic calculation. By doing so, a multiplexed differential pulse signal as shown in FIG. 46 is the above-mentioned multiplex differentiation) (by level-discriminating the Luss signal, differentiation of the amplitude Lo) (Differentiation of the amplitude Lo) (Differentiation of the amplitude given Luss, Ll) (differentiation of the amplitude A differential pulse signal as shown in FIG. 3G corresponding to the first control pulse signal is supplied to the first 7 lip-flop circuit 47A, and a differential pulse signal as shown in FIG. 3H corresponding to the second control pulse signal is supplied to the first 7 lip-flop circuit 47A. A differential pulse signal such as
Supply to 7B.

Here, the signal separation circuit 46 is configured, for example, as shown in FIG. By level discrimination at the level 1□ >J, >Ll, a differential pulse with an amplitude of L2 can be obtained at the first output terminal 52, and the second
The Zener diode 53 performs level discrimination at level 12 where L□>i2>Lo to obtain differential pulses with amplitudes Lo and L2, which are obtained by the first transistor 54 via the first Zener diode 51. By gating with a differential pulse having an amplitude of L2, a differential pulse having an amplitude of Lo can be obtained at the second output terminal 55, and furthermore, the multiplexed differential pulse signal is input to the second transistor 56 by a second transistor 56. By gating with the differential pulses of amplitudes Lo and L2 obtained through the Zener diode 53, a differential pulse of amplitude Ll can be obtained at the third output terminal 57.

The first 7-lip 70-tub circuit 47 has a LO
As shown in Figure 3, the first control pulse signal is set by a differential pulse with an amplitude of The voltage is supplied to the oscillator 21 of the regulator 20. Further, the second flip-flop circuit 47B is set with a differential pulse of Lo, and the second flip-flop circuit 47B is set with a differential pulse of Lo,
By resetting with the differential pulse, the second control pulse signal is regenerated as shown in FIG.
0 to the oscillator 31.

That is, in the embodiment configured as described above, each return control signal for stabilizing each output of each switching regulator 20, 30 is multiplexed in the state of a differential pulse signal,
The signal is transmitted through one pulse transformer 45. Since the pulse transformer 45 transmits differential pulses, one with a small capacity can be used. Further, the signal adder 44 side, that is, the control system circuit block 4
0P and the signal separation circuit 46 side, ie, the controlled system circuit block 408, can be isolated by the small capacity pulse transformer 45. Therefore, the control system can be insulated, and the output voltages of the switching regulators 20 and 30 can be adjusted and controlled in the insulated control system.

Note that the present invention is not limited to the isolated power supply device described in the above-mentioned embodiments, but can be applied to various control systems such as deflection adjustment and frequency adjustment of a high voltage block in a television receiver, for example. can.

As is clear from the description of the embodiments described above, according to the present invention, the control system circuit block is provided with a pulse transformer that insulates between a control system circuit block having a plurality of drive control functions and a controlled system circuit block. A multiplexed differential pulse signal is formed by adding and synthesizing the differential pulses obtained by differentiating each control pulse signal having a pulse width corresponding to the control amount, respectively, each having a different amplitude. Each control is performed based on each differential pulse obtained by supplying a pulse signal to a controlled system circuit block via the pulse transformer and discriminating the differential pulse signal according to the amplitude in the controlled system circuit block. By using an isolated drive control signal transmission circuit that reproduces pulse signals, a single small capacitance can be used to connect the control system and controlled system in various electronic devices equipped with multiple types of drive control functions. This makes it possible to control the controlled system on the ground side with an insulated control system, and to fully achieve the intended purpose.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the general configuration of an insulated television receiver. FIG. 2 is a block diagram showing an embodiment in which the present invention is applied to a multi-output power supply device. FIG. 3 is a time chart for explaining the operation of the above embodiment. FIG. 4 is a circuit diagram showing a specific example of the circuit configuration of the signal separation circuit in the above embodiment. 10... DC power supply input terminal 11.12... Output terminal 20.300... Switching regulator 21.31
0...Oscillator 22.32...Transformer 23.33...Switching transistor 24.34
... Rectifier circuit 40 ... Insulated drive control signal transmission circuit 40P ... Control system circuit block 408 ... O Controlled system circuit block 41 ... Reference pulse signal generator 42A, 42B ... Pulse width Modulators 43A, 43B@Q, differential circuit 44, 0 signal adder 45...pulse transformer 46...signal separation circuit 47A, 47B...fist flip 70 tuff circuit patent applicant Sony Corporation representative patent attorney Small Akira Ike

Claims (1)

[Claims] A pulse transformer is provided to insulate between a control system circuit block having multiple drive control functions and a controlled system circuit block, and each control pulse signal having a pulse width corresponding to the control amount is differentiated in the control system circuit block. A multiplexed differential pulse signal is formed by adding and combining the differential pulses obtained in different amplitude states, and the differential pulse signal is supplied to the controlled system circuit block via the pulse transformer. , an isolated drive control signal transmission circuit characterized in that each control pulse signal is regenerated based on each differential pulse obtained by discriminating the differential pulse signal according to the amplitude in the controlled system circuit block.