JPS60254840A - Straight receiving device of control system for power line carrier load - Google Patents

Abstract

PURPOSE:To output control signals of plural channels with the same level through one amplifying circuit and one demodulating circuit by selecting the value of an output level adjusting divided resistance provided to the smoothing circuit of a demodulation part. CONSTITUTION:A control signal modulated wave from a power line is passed through a coupler 1 and a filter 2, amplified by an amplifier 3, and demodulated by the demodulation part 4. The control signal modulated wave from a transmission side has its carrier AM-modulated with control signals of channels of different frequencies; the modulation side band is distant from a center carrier frequency as the frequency of the control signals are higher and higher, and the signal passed through the filter 2 is attenuated more at high frequencies than at low frequencies and then outputted. The demodulation part 4 performs rectification through diodes D1 and D2, its resistance R for smoothing is divided into parts (a)-(d), and driving parts 6-1, 6-2... are driven from voltage division points through discrimination parts 5-1, 5-2.... Divided resistance values of the resistance R are set that a control signal of higher frequency generates a higher output levels of control signals of respective channels are held constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a straight receiving device in a control system using an amplitude modulation type power line carrier system.

[Technical background and problems of the invention]

BACKGROUND ART Conventionally, as a remote control method, a power line carrier type control method is known in which a power line is used as a transmission path for a control signal to control a controlled device.

In such a power line carrier control system, when amplitude modulation is used as a control signal modulation method, a straight amplification method is conventionally used on the receiving side because of its simple circuit configuration and low cost. equipment is used. In such a straight receiving device, generally, for an amplitude modulated signal wave that has passed through a filter circuit having frequency characteristics as shown in FIG.
It is amplified and demodulated.

Incidentally, the center frequency of the frequency characteristic of the filter circuit is set to the carrier frequency f of the amplitude modulated signal wave. On the other hand, when the carrier wave of frequency f is amplitude-modulated by the control signal fp, the upper side wave of frequency (f + fp) and the upper side wave of frequency (
The lower side wave of r-rJ appears. Therefore, when the maximum frequency of the control signal is f, the upper and lower side waves constituting the upper side band from f to B+fP,) and the lower side band from f to (r-rp,) are filtered. This deviates from the center frequency f of the frequency characteristics of the circuit by the amount of the signal frequency.

Therefore, when an amplitude modulation control signal wave is passed through a filter circuit having the characteristics as shown in Fig. 1, the upper and lower side waves due to the low frequency signal wave (fl) pass through without being attenuated, but the The upper and lower side waves due to the high signal wave (h) are attenuated. That is, the higher the signal frequency is, the more the double-side band components of the amplitude modulated signal wave are attenuated and become smaller, and as a result, the higher frequency control signal has fewer signal components.

Therefore, when amplifying each amplitude modulated signal wave at the same rate in the amplification section, the output level of the high frequency control signal after amplification will be lower than that of the low frequency control signal, and the output level will be lower than that of the low frequency control signal. A drawback arises in that the frequency cannot be accurately controlled by the control signal.

Therefore, if an attempt is made to keep the output signal level constant, it becomes necessary to change the amplification degree for each control signal of each channel with a different frequency. Alternatively, it is necessary to add an AGC circuit that changes the amplification factor of the amplification section depending on the strength of each control signal.

Therefore, when trying to process control signals of multiple channels with one receiving device, the former case has the drawback of requiring equal number of amplifier circuits and demodulation circuits to the number of channels, and the latter case, Since the AGC circuit is added, the circuit becomes complicated and the cost becomes high.

[Purpose of the invention]

The present invention was made in order to eliminate the drawbacks of the conventional straight receiver described above, and it processes control signals of multiple channels with one amplifier circuit and one demodulation circuit, and also processes control signals of the same level for each control signal. It is an object of the present invention to provide a straight receiving device capable of obtaining an output signal of.

[Summary of the invention]

The present invention divides the resistance of the smoothing circuit in the demodulation section of a straight receiving device into the number of channels, and divides the demodulated signal output level to obtain a constant output level of the control signal of each channel. This allows a control signal to be processed by one amplifier circuit and one demodulation circuit.

[Embodiments of the invention]

Examples of the present invention will be described below. FIG. 2 is a block diagram of the straight receiving device according to the present invention. In the figure, 1 is a coupler which extracts a control signal modulated wave from a power line, and 2 is a filter section.

The control signal modulated wave is transmitted in the transmitting section to a carrier wave of 59 K Hy, obtained by a crystal oscillator, etc., and a carrier wave of 300 K Hy, obtained by a tuning fork oscillator, etc., set at a predetermined interval.
It is formed by performing amplitude modulation with a large number of control signal waves of ~300011z. Reference numeral 3 denotes an amplifying section that uniformly amplifies the control signal modulated waves of each channel. 4
is a demodulator, which, as shown in the third part, includes an input transformer T and diodes 11 . , D, and a smoothing circuit consisting of a capacitor C and a dividing resistor R divided into the number of channels. 5-,. 5-2.5-3. , , are the dividing points a, b, c, d, . . . of the dividing resistor R of the demodulator 3.
This is a judgment unit to which each output is input, and judges the control signal based on the frequency, duration, etc. of the demodulated output signal. 6-,. 6-2+, 6-3+, . . . are drive units respectively connected to the respective determination units, which drive controlled devices such as relays that perform blinking operations of lighting equipment.

In the receiver configured as described above, the control signal amplitude modulated wave taken in from the power line via the coupler 1 is passed through the filter section 2 having the frequency characteristics as shown in FIG.
For example, the amplitude modulated wave modulated by the control signal of low frequency 11 may have a large signal component that is hardly attenuated, as shown in Part 4 (c), depending on the level of the control signal frequency. However, the amplitude modulated wave modulated by the control signal of high frequency f2 is attenuated and becomes an amplitude modulated wave with small signal components as shown in Figure 4 (Bl). Compared to the amplitude modulated wave of low frequency f, fewer signal components are input to the amplification unit 3.The amplification unit 3 receives the amplitude modulated wave modulated by the control signal of any channel, Since the demodulator 4 is configured to perform amplification by a factor of -, modulated waves with different signal levels are input to the demodulator 4 due to signal waves with different frequencies.

In the present invention, the resistance R of the smoothing circuit in the demodulator 4
is divided into the number of channels, and each division point a, b, c
, d, . . . correspond to the demodulated signal output of each channel, and the output level thereof is made constant. That is, the division point a is the demodulation output end of the control signal with the highest frequency,
The dividing points are as follows.

c, d, . . . are used as demodulation output terminals of control signals of successively lower frequencies, and each division point a', b, c, d, . . .
This is to keep the output voltage corresponding to the control signal of each channel constant.

Therefore, even if amplitude modulated waves of different signal levels for each channel are inputted to the demodulator 4 from the amplifier 3, each control signal of the same output level is input to the judgment circuit 5-1 for each channel.
5-2. ' 5-3. You can make a comment to input each. As a result, each judgment circuit 5-15-2.
'5-:+, . 6-2゜6-3
．． It becomes possible to operate ... reliably.

Next, a specific configuration example of the smoothing circuit in the demodulator 4 will be shown. As for the control signals, each signal frequency is 559Hz,
Four-channel control signals of 579Hz, 61011z, and 631Hz are used. Then, capacitor C is 10
000pF, and the resistance value between each dividing point of the dividing resistor R is
Ω for Rab=3, Ω for Rbc=2, Rcd=
5 and Rdn = 70 KΩ.

Table 1 When the control signals of the four channels are input to the demodulation section having the smoothing circuit configured as described above, the output voltage at the dividing resistor ROa point is determined by each control signal having a different frequency, as shown in Table 1. , varies from 14V to 16V.

However, with a 631Hz control signal, the output voltage at point a, 6
10) For the 1z control signal, the output voltage at point b is 57911
The output voltage at point C for the z control signal and the output voltage at point d for the 55911z control signal are all 14V, and a constant output level can be obtained at each specific division point. Therefore, each division point a, b, c, d is 63
111z, 61011z, 57911z, 559
By connecting to each judgment circuit for Hz, a control signal with a constant output level can be input to the judgment circuit for each channel.

〔Effect of the invention〕

As described above based on the embodiments, the present invention includes a dividing resistor for output level adjustment in the smoothing circuit of the demodulator in a straight receiver, so that the demodulated output level is constant for each control signal of a different frequency. The dividing points of the dividing resistor are selected as shown in FIG. In some cases, the amplification circuit and demodulation circuit can be made common, and the input signal level to the judgment circuit for each channel can be made constant. The controlled device can be operated reliably.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the frequency characteristics of a filter used in a straight receiving device in an amplitude modulated power supply control system, and FIG. 2 is a block diagram of an embodiment of the straight receiving device of the present invention. The configuration diagram, FIG. 3 is a diagram showing an example of the configuration of the demodulation section of the receiving device, and FIG. 4 WiB+ is,
FIG. 3 is a waveform diagram of amplitude modulated waves generated by control signals having different frequencies after passing through a filter section. In the figure, ■ is a combiner, 2 is a filter section, 3 is an amplification section, 4 is a demodulation section, 5-, . 5-2.5-:1. ,. 0. 6-1.6-2.6-*, . 1st hearing Figure 2 Figure 3 Figure 4 (A) (B) Procedural amendment August 9, 1980 Manabu Shiga, Commissioner of the Patent Office 1, Indication of the case 1982 Patent Application No. 109617 2 , Title of the invention Straight receiving device in power line carrier load control system 3, Person making the amendment 4, Agent 6, Number of inventions increased by the amendment None 7, Subject of the amendment Detailed description of the invention in the specification column 8 , ``Power line L'' on page 5, lines 7-8 and line 6-8 of the specification of contents of ψ correction
The text has been corrected to read "power line 7." Nige iN\

Claims (1)

[Claims] In a straight receiving device using a control method using an amplitude modulation power line carrier method, a dividing resistor for adjusting the output level is installed in the smoothing circuit of the demodulator so that the demodulated output level is constant for each control signal of different frequencies. A straight receiving device characterized in that the dividing point of the dividing resistor is selected and the output signal at each dividing point is inputted to a determination circuit for each control signal.