Time division multiplexing load control system having manual switch for directly controlling loads

• US 4,608,561 A
• Filed: 09/12/1983
• Issued: 08/26/1986
• Est. Priority Date: 09/20/1982
• Status: Expired due to Term

• Current Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Masuda, Toshiyuki, Kojima, Yutaka, Hisamatsu, Nobuo
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US06/531,502
• Time in Patent Office: 1,079 Days
• Field of Search: 307/3, 307/11, 307/12, 307/69, 307/70, 340/825.52, 340/825.06, 340/825.07, 340/825.17, 340/825.18, 370/92, 370/93
• US Class Current: 340/9.1
• CPC Class Codes: H04Q 9/14 Calling by using pulses
• CPC Class Codes: H05B 47/155 Coordinated control of two or more light sources

Abstract

A time division multiplexing load control system having a central controller unit for controlling individual terminal units to connect and disconnect loads connected respectively thereto and manual switch means for directly controlling the loads without reverting to the central controller unit is disclosed. A plurality of terminal units are connected through a shared line to the central controller unit to be controlled thereby so as to turn on/off the loads connected to respective terminal units. Each terminal unit connecting the loads is provided with a load-switching circuit for actuating respective load driving relays incorporated therein to connect and disconnect the loads. The load-switching circuit includes switch means which responds to output data signal from the central controller unit to open and close the load-switching circuit for the ON/OFF drive of the load remote from the central controller unit. Also included in each load-switching circuit are manual switch means for actuating the load driving relay independently of the output signal from the controller unit and detecting means for detecting the state of the load driving relay and transmitting such state to the controller unit so that the controller unit always acknowledges the load condition, irrespective of whether the load has been driven by the controller unit or by the manual switch means manipulated by a person near the load.

Claims

1. A time division multiplexing load control system, comprising:

a central controller unit for generating, based upon input data accepted through an incorporated input device, output data signals, each of which includes at least an address receiving a response signal; and

a plurality of terminal units connected to the central controller unit, said central controller unit transmitting said output data signals sequentially and periodically to respective ones of said terminal units, each terminal unit responding to a corresponding address signal which accompanies each control signal and receiving said control signal to be controlled thereby and transmitting a response signal to the central controller unit in accordance with the control signal and the response-waiting signal, said output data signals and response signals being transmitted as time division multiplexing signals between the central controller unit and each of the terminal units;

at least one of the terminal units being provided with one or more associated load-switching circuits defining the associated terminal unit as being connected to one or more loads, each load-switching circuit comprising;

a latch-in load driving relay having a main contact for connecting and disconnecting the load and having a first changeover contact, two first contact members which are connected in said load-switching circuit respectively between said first changeover contact and two first diodes of opposite polarity which alternatively conduct to allow current to flow in a respective direction in said load-switching circuit;

reversing switch means connected between an AC power source and the load driving relay and having a second changeover contact, two second fixed contact members which are connected in said load-switching circuit respectively between said second changeover contact and two second diodes of opposite polarity for responding to the control signal from the central controller unit to alternatively cause the conduction of said two second diodes to allow current to flow in a respective direction in said load-switching circuit;

manual switch means connected in parallel with said reversing switch means for operating said load-switching circuit independently of the function of said reversing switch means; and

a photocoupler detecting means including a light emitting diode connected in parallel with said current reversing switch means for emitting light in response to the current flowing in one direction in said load-switching circuit, and a photodetector which detects the emission of light and transmits a response signal representative of such emission to the central controller unit;

said load driving relay being responsive to a forward current flow through either of the two first diodes to move said main contact for connecting and disconnecting the load and at the same time to move the first changeover contact from one position to another position;

said reversing switch means futher including a normally open contact connected in series with said second changeover contact, both the normally open contact and the second changeover contact being controlled by said control signal from the central controller unit in such a way that the second changeover contact moves subsequent to the closing of the normally open contact and is kept latched in its last position, whereby said second changeover contact when moving to either of two positions thereof in response to the control signal causes a current to flow in either of two directions in said load-switching circuit through the first and second diodes which are arranged in the same direction until the first changeover contact is reversed by said current to prevent further current flow, said manual switch means further comprising a switch device for causing a current in the load-switching circuit to flow in a direction so as to actuate the load driving relay for turning on the load and for causing a current in the same circuit to flow in a opposite direction so as to actuate the load driving relay for turning off the load.

2. A time division multiplexing load control system, comprising:

a central controller unit for generating, based upon input data accepted through an incorporated input device, output data signals each of which includes at least an address signal, a control signal, and a response-waiting signal for receiving a response signal; and

a plurality of terminal units connected to the central controller unit, said central controller unit transmitting such output data signals sequentially and periodically to respective ones of said terminal units, each terminal unit responding to a corresponding address signal which accompanies each control signal and receiving said control signal to be controlled thereby and transmitting a response signal to the central controller unit in accordance with the control signal and the response-waiting signal, said output data signals and response signals being transmitted as time division multiplexing signals between the central controller unit and each of the terminal units;

at least one of the terminal units being provided with one or more associated load-switching circuits defining the associated terminal units as being connected to one or more loads, each load-switching circuit comprising;

a latch-in load driving relay having a main contact for connecting and disconnecting the load and having a first changeover contact, two first fixed contact members which are connected in said load-switching circuit respectively between said first changeover contact and two first diodes of opposite polarity which alternatively conduct to allow current to flow in a respective direction in said load-switching circuit;

reversing switch means connected between an AC power source and the load driving relay and having a second changeover contact, two second fixed contact members which are connected in said load-switching circuit respectively between said second changeover contact and two second diodes of opposite polarity for responding to the control signal from the central controller unit to alternatively cause the conduction of said two second diodes to allow current to flow in a respective direction in said load-switching circuit;

manual switch means connected in parallel with said reversing switch means for operating said load-switching circuit independently of the function of said reversing switch means; and

a photocoupler detecting means including a light emitting diode connected in parallel with said reversing switch means for emitting light in response to the current flowing in one direction in said load-switching circuit, and a photodetector which detects the emission of light and transmits a response signal representative of such emission to the central controller unit;

said load driving relay being responsive to a forward current flow throgh either of the two first diodes to move said main contact for connecting and disconnecting the load and at the same time to move the first changeover contact from one position to another position;

said reversing switch means further including a normally open contact connected in series with said second changeover contact, both the normally open contact and the second changeover contact being controlled by said control signal from the central controller unit in such a way that the second changeover contact moves subsequent to the closing of the normally open contact and is kept latched in its last position, whereby said second changeover contact when moving to either of two positions thereof in response to the control signal causes a current to flow in either of two directions in said load-switching circuit through the first and second diodes which are arranged in the same direction until the first changeover contact is reversed by said current to prevent further current flow, said manual switch means further comprising a single momentary action switch device and an operating circuit which upon a predetermined operation of the switch device detects which of said two first diodes are connected in the load-switching circuit and causes current to flow in the load-switching circuit in the corresponding direction allowed by the thus detected first diode until the other first diode becomes connected in said load-switching circuit to reverse the load driving relay.