JPS60250739A - Console unit for remote control - Google Patents

Abstract

PURPOSE:To suppress the energy of impulsive noise without reducing the Q of a tuning circuit in a coupling transformer with a simple constitution, and to prevent parts from damage and the titled console unit from malfunction by connecting a voltage suppressing element in parallel with the primary coil of the coupling transformer. CONSTITUTION:The coupling transformer T is formed in a remote control console unit of a power line carrier system, the primary side of the transformer T is connected to the power line through a capacitor C1 and a power supply circuit 2 is connected to the power line through a rectifier circuit B. A capacitor C2 and a signal processing circuit 1 are connected to the secondary side of the transformer T to constitute the tuning circuit of carrier frequency by the inductance of the secondary coil and the capacitor C2. The voltage suppressing element VR having suppressing voltage higher than the peak value of a carrier wave signal is connected in parallel with the primary coil of the transformer T. Thus, the energy of an impulsive noise is suppressed by the element VR and a varister ZNR without reducing the Q of the tuning circuit of the transformer T, the parts is prevented from damages and the console unit is prevented from malfunction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a remote control terminal 1 used in an indoor power line transportation system.

[Background Art 1] Generally, in this type of terminal device, an IFT (intermediate frequency transformer) type coupling transformer is often used for signal coupling with a power line. This type of coupling transformer has the advantage of being able to use a tuned circuit to increase the selectivity and increase the detection sensitivity of the carrier signal, but on the other hand, the withstand voltage between the negative side coil and the secondary side coil is extremely low, at around 100 VAC. Since the voltage is low, there is a risk of dielectric breakdown due to impact noise transmitted through the power line, and even if dielectric breakdown does not occur, high voltage noise may enter the signal processing circuit, causing malfunction or malfunction. Ta.

Figure 4 shows a circuit diagram of a conventional terminal device, in which a coupling capacitor C1 is connected between power line connection terminals alaz.
Connect the primary coil full of the coupling transformer T through
The secondary coil is connected to the signal processing circuit 1, and at this time, the inductance of the coil and the capacitance of the capacitor C2 added to the secondary side form a tuned circuit for high-frequency signals, increasing the selectivity. By doing so, the signal detection sensitivity is increased. In the figure, 2 is the power supply circuit, 3
is a control circuit, 4 is a monitoring circuit, and the signal processing circuit 1 controls the load based on the received control data, and
Data from the monitoring sensor is sent back via a carrier signal.

Conventionally, in order to prevent impact noise, a varistor Z was connected between the power line connection terminals 8182, as shown in FIG.
NR was inserted, but the suppression voltage value of this varistor is higher than the commercial power supply voltage, and the noise voltage passing through the varistor is boosted by the winding ratio of the coupling transformer, so it is the same as the carrier signal. There is a high possibility that the insulation between the two coils will be destroyed due to frequency component noise, and therefore there is a problem in that the Q of the tuning circuit cannot be made very high in order to improve the selectivity.

[Object of the Invention] The present invention has been made in view of the above problems, and its purpose is to improve the detection sensitivity by increasing the selectivity of the tuning circuit of the IFT type coupling transformer. Moreover, it is an object of the present invention to provide a remote control terminal device that can prevent insulation breakdown of a coupling transformer and malfunction of a signal processing circuit due to impulsive noise.

[Disclosure of the Invention] The present invention provides a remote control terminal for a power line carrier system that transmits information such as load control data and sensor monitoring data by superimposing a high frequency signal on an indoor power line. A capacitor is connected in parallel with the secondary side fill of the signal input/output coupling transformer connected to the power line via a pulling capacitor to form a tuning circuit for the above high frequency signal, and a capacitor is connected in parallel with the negative side coil. This device is characterized by the connection of a voltage suppression element with a suppression voltage value higher than the peak value of the high-frequency signal, and prevents defects due to impulsive noise without sacrificing signal detection sensitivity. .

FIG. 1 shows an embodiment of a remote control terminal according to the present invention. In the figure, reference numeral 1 denotes a signal processing circuit consisting of a receiving section and a transmitting section, which receives a transmission signal including a terminal device address and control data from a central control panel via a power line,
If the terminal device address matches its own address,
The load is controlled via the control circuit 3 based on the control data, and the load condition is read from the sensor via the monitoring circuit 4 and sent back from the transmitter. The power supply circuit 2 supplies power to the signal processing circuit 1, detects zero cross points, and generates a synchronization clock for signal processing. Note that F 2 and F 2 are block filters, and B is a rectifier circuit. The secondary side coil of the coupling transformer T is connected to the input/output terminal of the signal processing circuit 1, and the negative side coil is connected to the power line connection terminal ala2 via the coupling capacitor CI.

The feature of the present invention is that a capacitor C2 is connected in parallel with the secondary coil of this coupling transformer to generate both coils.

The inductance of C2 and the capacitance of capacitor C2 form a tuned circuit for the carrier signal frequency, and
- A voltage suppressing element VR having a suppressing voltage value higher than the peak value of the carrier signal is connected in parallel with the next coil. This voltage suppressing element ■R is a nonlinear resistance element whose resistance value decreases as the applied voltage increases, like a varistor.
) and (c) using two Zener diodes ZD, or by connecting the required number of diodes D in antiparallel as shown in (d) of the figure.

FIG. 3 explains the operation according to the configuration of the present invention.
B shows the case where the Q of the tuned circuit is high, and B shows the case where the Q is low. Vt is the suppression voltage value (for example, 20■),
The peak value of the impulsive noise applied to the fill can also be lowered by lowering the Q, but in that case the signal voltage will also be attenuated, resulting in a decrease in detection sensitivity. On the other hand, if you use a voltage suppression element to cut off voltages higher than some levels without lowering the Q, the noise energy in the shaded area in the diagram will be cut.
Signal voltages with peak values lower than the normal suppression voltage value Vt are not cut, and therefore high signal detection sensitivity can be maintained without sacrificing selectivity.

[Effect of the invention 1 As described above, in the present invention, by using a simple configuration in which a voltage suppressing element is connected in parallel with the primary coil of a coupling transformer, impulsive noise can be suppressed without lowering the Q of the tuning circuit of the coupling transformer. This has the advantage of suppressing energy and preventing dielectric breakdown between the coils of the coupling transformer, damage to the secondary semiconductor components, and malfunctions due to noise.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing one embodiment of the present invention, and FIG.
Figures (a), (b), (c), and (d) are circuit diagrams showing various configuration examples of the voltage suppressing element used in the above, Figure 3 is a graph showing the operation of the same, and Figure 4 is a block circuit of a conventional example. It is a diagram. 1 is a signal processing circuit, 2 is a power supply circuit, 3 is a control circuit, 4 is a monitoring circuit, T is a coupling transformer, C and C2 are capacitors,
VR is a voltage suppression element. Agent Patent Attorney Ishi 1) Chief 7 Figure 1 Figure 2

Claims (1)

[Claims] (1) In a remote control terminal for a power line carrier system that transmits information such as load control data and sensor monitoring data by superimposing a high-frequency signal on an indoor power line, the negative side is connected to the power line via a coupling capacitor. A capacitor is connected in parallel with the secondary coil of the connected signal input/output coupling transformer to form a tuning circuit for the high frequency signal, and a capacitor is connected in parallel with the negative side coil to suppress the high frequency signal higher than the peak value of the high frequency signal. A remote control terminal comprising a voltage suppressing element having a voltage value connected thereto.