GB2163308A - Switching apparatus - Google Patents
Switching apparatus Download PDFInfo
- Publication number
- GB2163308A GB2163308A GB08517098A GB8517098A GB2163308A GB 2163308 A GB2163308 A GB 2163308A GB 08517098 A GB08517098 A GB 08517098A GB 8517098 A GB8517098 A GB 8517098A GB 2163308 A GB2163308 A GB 2163308A
- Authority
- GB
- United Kingdom
- Prior art keywords
- switch
- switches
- operator
- switching apparatus
- power switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/002—Switching arrangements with several input- or output terminals
- H03K17/005—Switching arrangements with several input- or output terminals with several inputs only
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H7/00—Devices for introducing a predetermined time delay between the initiation of the switching operation and the opening or closing of the contacts
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/16—Modifications for eliminating interference voltages or currents
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/28—Modifications for introducing a time delay before switching
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2300/00—Orthogonal indexing scheme relating to electric switches, relays, selectors or emergency protective devices covered by H01H
- H01H2300/054—Application timeslot: duration of actuation or delay between or combination of subsequent actuations determines selected function
Landscapes
- Keying Circuit Devices (AREA)
Abstract
Two operator switches 4 and 6 are serially coupled with a sampling switch 8, a switch state detector 12 and two timers 18 and 20 between a grounded terminal and a power switch 22 of electrical equipment. When either of the switches 4 and 6 are operated, the path to earth is detected by the detector 12 and a signal is passed to the appropriate timer 18 or 20. The timers 18 and 20 do not however provide a signal to operate the power switch 22 unless either switch 4 or 6 is operated for longer than the time periods of the timers 18 and 20 (eg. two seconds). <IMAGE>
Description
SPECIFICATION
Switching apparatus
The present invention relates to switching apparatus and in particular, but not exclusively, to switching apparatus incorporated in electrical equipment.
Electrical equipment, such as a transceiver, is normally provided with an externally mounted switch to enable the equipment to be switched off when not in use. These switches can take many forms but push-button or toggle switches are frequently used for this purpose.
Switches of this type, however, require only a simple physical action to operate and hence, are subject to accidental actuation. External switches on portable communications equipment are particularly susceptable to accidental actuation during transit of'the equipment.
Such equipment is usually battery powered and, therefore, accidental switch operation during transit can lead to discharge of the supply batteries and failure of the equipment.
It has previously been proposed to remedy this problem by using multistep mechanical rotary switches or switches which require multiple key strokes for operation. However these types of switches produce an increase in the complexity of the design or operation of the equipment.
It is an object of the present invention to provide switching apparatus which is simple to actuate but which is less susceptible to accidental operation than the above mentioned types of switches.
Switching apparatus comprising a serially coupled operator switch, an earth leakage detector and a timer, for connection with a grounded terminal and a power switch of electrical apparatus, arranged such that the operator switch must be activated for longer than a predetermined period of time, as determined by the timer, before the power switch of the electrical apparatus, to which the switching apparatus is arranged for connection, is activated.
The present invention will now be described, by way of example, with reference to the accompanying drawings which illustrates a schematic diagram of switching apparatus in accordance with the present invention.
Referring to the drawing, switching apparatus 2 comprises operator switches 4 and 6 such as conventional mechanically actuated push-button switches. The switch 4 may be used to switch on equipment in which the switching apparatus is incorporated and the switch 6 may be used to switch off the equipment.
One terminal of the switches 4 and 6 is connected to ground, such as a grounded terminal of the equipment, and the other terminal of each switch 4 and 6 is connected to terminals on a change over sampling switch 8. The common terminal on the sampling switch 8 is connected to input 10 of an earth detector 12.
The earth detector 1 2 is provided with outputs 14 and 1 6 to indicate respectively when the switches 4 and 6 have been made.
The outputs 14 and 6 of the earth detector 1 2 are connected via timers 1 8 and 20 to a main power switch 22. The timers 1 8 and 20 have, preferably, a predetermined time period of two seconds and the power switch 22 is connected in the main power supply line of the electrical equipment incorporating the switching apparatus.
The switching apparatus 2 operates as follows. The sampling switch 8 samples sequentially, the state or condition of the switches 4 and 6, that is, whether the switches 4 and 6 are in a make or break condition.
When either of the switches 4 and 6 are made this will be recognised by the earth detector 1 2 as the input 10 of the earth detector 1 2 is connected to ground through the sampling switch 8 and the made switch 4 or 6.
The earth dertector 1 2 then provides an output signal on either output 1 4 or 1 6 which is fed through either timer 1 8 or 20 to the power switch 22. The power switch 22 is actuated to switch on or switch off the equipment. However, as the timers 1 8 and 20 are located in the lines between the earth detector 1 2 and the power switch 22 the input 10 of the earth detector 1 2 must be connected to ground for at least the predetermined time period of the timers 1 8 and 20 to enable the output signal from the earth detector 1 2 to pass through either timer 1 8 or 20 to the power switch 22.As the input 10 is connected to ground through either switch 4 or 6, switch 4 or 6 must be activated for at least the predetermined time period of timers 1 8 and 20 before the power switch 22 is operated. For example, assume that it is required to switch on the equipment and that the timers 1 8 and 20 have predetermined time periods of 2 seconds. The switch 4 is made to connect the input 10 of the earth detector 1 2 to ground through the switch 4 and the sampling switch 8. The earth detector 12 produces an output signal on output 14 which is fed to timer 1 8. However, a signal does not appear on the output of timer 1 8 for 2 seconds and hence, the switch 4 must be made for at least two seconds before the power swith 22 is actuated. If the switch 4 is made for less than 2 seconds the signal is removed from the input of the timer 1 8 before the expiry of the 2 second time period and hence, the power switch 22 is not actuated. It can be seen, therefore, that a request to switch on or switch of the equipment must persist for at least the predetermined time period set in timers 1 8 and 20 before the power switch 22 is activated.
Claims (5)
1. Switching apparatus comprising a serially coupled operator switch, an earth leakage detector and a timer, for connection to a grounded terminal and a power switch of electrical apparatus, arranged such that the operator switch must be activated for longer than a predetermined period of time, as determined by the timer, before the power switch of the electrical apparatus, to which the switching apparatus is arranged for connection, is activated.
2. Switching appartus according to claim 1 comprising two operator switches and two timers serially coupled with the earth leakage detector and wherein the switching apparatus is arranged for one operator switch to be operative to make the power switch of the electrical apparatus and the other operator switch to be operative to break the power switch of the electrical apparatus when the appropriate operator switch is activated for longer than the predetermind period of time.
3. Switching apparatus according to claim 2 comprising a scanning switch, serially coupled to the operator switches, for monitoring the condition of the two operator switches.
4. Switching apparatus according to any one of claims 1 to 3 wherein the operator switches comprise push button switches.
5. Switching apparatus substantially as hereinbefore described with reference to the accompanying drawing.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB848417415A GB8417415D0 (en) | 1984-07-07 | 1984-07-07 | Switching apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8517098D0 GB8517098D0 (en) | 1985-08-14 |
GB2163308A true GB2163308A (en) | 1986-02-19 |
Family
ID=10563602
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB848417415A Pending GB8417415D0 (en) | 1984-07-07 | 1984-07-07 | Switching apparatus |
GB08517098A Withdrawn GB2163308A (en) | 1984-07-07 | 1985-07-05 | Switching apparatus |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB848417415A Pending GB8417415D0 (en) | 1984-07-07 | 1984-07-07 | Switching apparatus |
Country Status (1)
Country | Link |
---|---|
GB (2) | GB8417415D0 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2232833A (en) * | 1989-04-27 | 1990-12-19 | Toshiba Kk | Cooking appliance control |
FR2696089A1 (en) * | 1992-09-25 | 1994-04-01 | Gen Electric Cgr | Device for handling a radiology device. |
EP1662239A3 (en) * | 2004-10-20 | 2006-06-07 | Omron Healthcare Co., Ltd. | Electronic clinical thermomether |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB930484A (en) * | 1959-07-30 | 1963-07-03 | John Peter Woodnutt | Improvements in or relating to electric control systems |
GB1372684A (en) * | 1973-01-31 | 1974-11-06 | Bellis R E | Touch sensitive power control system |
US4053790A (en) * | 1976-08-31 | 1977-10-11 | Heath Company | Power line switch with time delay turn off |
GB1511708A (en) * | 1975-11-08 | 1978-05-24 | Plessey Co Ltd | Electrical contact-bounce compensator |
GB1542692A (en) * | 1975-06-16 | 1979-03-21 | Epitoegepgyarto Vallalat | Electronic time switch |
GB2034043A (en) * | 1978-10-09 | 1980-05-29 | Turnright Controls | Improvements in or Relating to Controls for Electrical Circuits |
GB1579086A (en) * | 1977-12-23 | 1980-11-12 | Towmotor Corp | Electromagnetic contactors |
GB2060171A (en) * | 1979-08-14 | 1981-04-29 | Hill Rotherham Ltd Thoma | A touch sensitive control |
GB2105930A (en) * | 1981-07-28 | 1983-03-30 | Carpano & Pons | Apparatus for controlling electrical loads each having at least two states |
GB2135143A (en) * | 1983-02-01 | 1984-08-22 | Ti Russell Hobbs Ltd | Electric heating appliance |
-
1984
- 1984-07-07 GB GB848417415A patent/GB8417415D0/en active Pending
-
1985
- 1985-07-05 GB GB08517098A patent/GB2163308A/en not_active Withdrawn
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB930484A (en) * | 1959-07-30 | 1963-07-03 | John Peter Woodnutt | Improvements in or relating to electric control systems |
GB1372684A (en) * | 1973-01-31 | 1974-11-06 | Bellis R E | Touch sensitive power control system |
GB1542692A (en) * | 1975-06-16 | 1979-03-21 | Epitoegepgyarto Vallalat | Electronic time switch |
GB1511708A (en) * | 1975-11-08 | 1978-05-24 | Plessey Co Ltd | Electrical contact-bounce compensator |
US4053790A (en) * | 1976-08-31 | 1977-10-11 | Heath Company | Power line switch with time delay turn off |
GB1579086A (en) * | 1977-12-23 | 1980-11-12 | Towmotor Corp | Electromagnetic contactors |
GB2034043A (en) * | 1978-10-09 | 1980-05-29 | Turnright Controls | Improvements in or Relating to Controls for Electrical Circuits |
GB2060171A (en) * | 1979-08-14 | 1981-04-29 | Hill Rotherham Ltd Thoma | A touch sensitive control |
GB2105930A (en) * | 1981-07-28 | 1983-03-30 | Carpano & Pons | Apparatus for controlling electrical loads each having at least two states |
GB2135143A (en) * | 1983-02-01 | 1984-08-22 | Ti Russell Hobbs Ltd | Electric heating appliance |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2232833A (en) * | 1989-04-27 | 1990-12-19 | Toshiba Kk | Cooking appliance control |
US5097113A (en) * | 1989-04-27 | 1992-03-17 | Kabushiki Kaisha Toshiba | Touch switch arrangement for a heating cooking appliance |
GB2232833B (en) * | 1989-04-27 | 1993-08-18 | Toshiba Kk | Heating cooking appliance |
FR2696089A1 (en) * | 1992-09-25 | 1994-04-01 | Gen Electric Cgr | Device for handling a radiology device. |
US5675227A (en) * | 1992-09-25 | 1997-10-07 | Ge Medical Systems | Device for maneuvering a radiology appliance |
EP1662239A3 (en) * | 2004-10-20 | 2006-06-07 | Omron Healthcare Co., Ltd. | Electronic clinical thermomether |
Also Published As
Publication number | Publication date |
---|---|
GB8517098D0 (en) | 1985-08-14 |
GB8417415D0 (en) | 1984-08-30 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |