WO2009116949A1 - Interrupteur de sécurité - Google Patents

Interrupteur de sécurité Download PDF

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Publication number
WO2009116949A1
WO2009116949A1 PCT/SE2009/050298 SE2009050298W WO2009116949A1 WO 2009116949 A1 WO2009116949 A1 WO 2009116949A1 SE 2009050298 W SE2009050298 W SE 2009050298W WO 2009116949 A1 WO2009116949 A1 WO 2009116949A1
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WO
WIPO (PCT)
Prior art keywords
time
devised
contact
switch
safety switch
Prior art date
Application number
PCT/SE2009/050298
Other languages
English (en)
Inventor
Billy Jacquet
Dick Holmén
Original Assignee
Billy Jacquet
Holmen Dick
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Billy Jacquet, Holmen Dick filed Critical Billy Jacquet
Publication of WO2009116949A1 publication Critical patent/WO2009116949A1/fr

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/027—Details with automatic disconnection after a predetermined time
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
    • H05B1/0227—Applications
    • H05B1/0252—Domestic applications
    • H05B1/0255—Irons
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
    • H05B1/0227—Applications
    • H05B1/0252—Domestic applications
    • H05B1/0258—For cooking
    • H05B1/0269—For heating of fluids

Definitions

  • the present invention relates generally to safety devices for electronic apparatuses and more specifically to a safety switch which is devised to disconnect the current according to predetermined rules.
  • Timer devices that can be connected between the socket and the plug, and which can be set to disconnect or connect the current at predetermined points in time are well known. Some apparatuses, such as percolators, also have a built-in timer which disconnects the current after a certain time.
  • the overall object of the present invention is to provide a solution to the problem of providing a settable safety switch which is activated at power-on and which disconnects an electrical device connected thereto in case of malfunction, or after a certain time if it was forgotten switched on.
  • Fig 1 to Fig 12 show exemplifying embodiments of the invention.
  • Fig 1 shows a schematic diagram of a preferred embodiment of the safety switch.
  • Fig 2 shows (top) a detector circuit with load not connected and BL open and (below) a detector circuit with load connected and BL closed.
  • Fig 3 shows a schematic outline of the invention for example at serial capacitive load.
  • Fig 4 shows (top) a detector circuit at serial capacitive load with load not connected and BL open, and (below) a detector circuit at serial capacitive load with load connected and BL closed.
  • Fig 5 shows an embodiment with a current detector.
  • Fig 6 shows an example of a current sensor, Hall Effect.
  • Fig 7 shows a time diagram for activation of load and timer.
  • Fig 8 shows an example of time behavior at dynamic pulse/pause load.
  • Fig 11 shows an embodiment with combined detector and current sensor.
  • Fig 12 shows a time diagram with two timers, one for pulse and one for pause.
  • the invention provides a surveillance device which in an advantageous embodiment comprises a safety switch with or without timer function, which is devised to disconnect the current to an electrical device connected to the surveillance device (the safety switch) according to predetermined rules.
  • the safety switch is devised such that, in similarity with an ordinary timer, a time can be set during which the safety switch shall be allowed to let through current. Thereafter the safety switch is activated each time the electrical device is switched on with its ordinary power-on switch, and disconnects if the preset time is exceeded.
  • a great advantage is that the electric current circuit to the load remains open and no voltage is applied to the apparatus, when the apparatus is not in use.
  • Another advantage is that the invention becomes automatic and does not need maneuvering at each use.
  • the inventive safety switch is particularly advantageous to use as a surveillance device for devices that are controlled by any type of sensor. For example a pressure guard which controls a pump, the thermostat which controls an iron, a light sensor which turns on a spotlight or a timer which controls a motor.
  • a pressure guard which controls a pump
  • the thermostat which controls an iron
  • a light sensor which turns on a spotlight
  • a timer which controls a motor.
  • GND Electrical reference ground
  • i(t) current
  • time dependent K Comparator
  • MC Micro Controller (built-in microcomputer)
  • MMI Man-Machine Interface (buttons, light emitting diod, display)
  • N Neutral (in 220 VAC voltage system)
  • NC Normally Closed
  • R Resistance
  • RD Relay Driver
  • VDD Positive direct current
  • Figure 1 shows an embodiment of a first, simple realization of a safety switch ST, where the safety switch ST is connected to a 220 VAC socket and an electrical apparatus L is connected to the safety switch ST. It is foremost intended for static load, i.e. the apparatus L is turned on and after a certain time it has finished its task. L does not comprise a function which varies with external circumstances during the task. An example of this is a water boiler.
  • the safety switch ST comprises an AC/DC converter VC to supply energy to the unit, which feeds the included components with a driving voltage VDD.
  • a built-in microcomputer MC is provided with a control program SP, comprising e.g. a number of timers in a program modulus TF which supervises times that are set and run out.
  • the user can interact with the apparatus, e.g. set times and functions, read data etc. via a user interface MMI, which can comprise buttons, light-emitting diods and/or displays, for instance a reset button RST.
  • the microcomputer is active, continuously or is invoked from an energy saving mode with a suitable interval, and measures/monitors the output voltage u from a detector D.
  • the detector D will be further described in connection to figure 2.
  • the output voltage « is coupled to an analogue-digital converter ADC, alternatively a comparator K in the microcomputer MC.
  • the switch-disconnector BL is open and the connected apparatus shows a very high electrical resistance, i.e. interruption.
  • the switches are in position NC (normally connected), connecting the apparatus to the detector D and the microcomputer MC detects an interruption while, at the same time, the current and the switch in both lines N and F are disconnected to the second contact by relay RE. In this position the voltage from the safety switch to the load is thus disconnected by relay RE.
  • the switch-disconnector BL can be activated manually, by a switch-disconnector function FB of the device, e.g. a switch which triggers the timing.
  • the timing may also be started by simply connecting (or inserting) the apparatus/load L to the safety switch with timer function.
  • the apparatus L has finished its task at tl, i.e. before the time t2, the VAC line continues to be connected in order to disconnect at t2. This means that the apparatus will not be able to consume current if something was wrong or if it would have been forgotten turned on. A new time cycle can be started by turning on the apparatus.
  • the apparatus in Figure 7A is activated as the time tO is started - the apparatus L is shortly turned off at PO and is turned off.
  • the pause time PO is started - the apparatus is activated again at Pl and the time Pl reset to zero.
  • the apparatus L is again turned off at the next pause at PO, whereby the time PO is started again.
  • This time the preset time P is exceeded at P2, whereupon the time PO is reset and the time T is also reset.
  • the apparatus L can be started with a new full time T of operation. This is enabled although the time t2 has not lapsed.
  • Fig 2 shows an embodiment of the detector D which is based upon the principle of voltage division.
  • the switch-disconnector BL When the switch-disconnector BL is open (interruption) the load ZL is "infinite" and the voltage u becomes equal to VDD.
  • the switch-disconnector BL When the switch-disconnector BL is closed the load ZL is coupled to the detector D and the voltage u becomes dependent on the voltage division and the selected resistors R. In the example in figure 2 the voltage u becomes about 0.5VDD which easily can be detected by the ADC/K in the microcomputer MC.
  • Fig 3 shows another embodiment of the safety switch, suitable for certain apparatuses L, which may comprise other and more components, e.g. a condensate C blocking direct current, but also inductances, transformers and non-linear components, e.g. semiconductors.
  • apparatuses may for example be battery chargers and the switch- disconnector function of the load may form when a battery, with its low inner impedance, is connected to the charger.
  • the detector according to the embodiment in figure 2 will then always detect interruption.
  • the microcomputer MC may control another embodiment of the detector D with a time dependent alternating signal.
  • f(t) may be a square wave which is generated by the microcomputer MC.
  • This alternative embodiment of the detector D is also based on the principle of voltage division, but is fed by a time dependent alternating signal Uin(t), see figure 4.
  • Uin(t) time dependent alternating signal
  • the switch-disconnector BL When the switch-disconnector BL is open (interruption) the load ZL is "infinite" and the voltage U(t) becomes equal to Uin(t).
  • the switch-disconnector BL When the switch-disconnector BL is closed the load ZL is coupled to the detector D and the voltage U(t) becomes a function / fUin(t)J which is different from Uin(t) and can be distinguished by ADC/K in the microcomputer MC.
  • the time dependent signal Uin(t) can also be applied to the detector with several different frequencies, and the variation in the responses u(t) may then be characterized by the impedance ZL of the load.
  • Figure 5 shows an exemplifying embodiment of the safety switch with a current sensor CS instead of the detector D.
  • the switch-disconnector function FB and its closing and opening of BL respectively may then be detected by measuring the current through the current sensor CS.
  • the output signal u(t) may e.g. be a voltage which is proportional to the current.
  • Different types of current sensors may be: current transformer, current shunt, Hall effect sensors and/or Rogowski coil.
  • Figure 6 shows how ST, with e.g. a Hall effect sensor as a CS renders good safety between the alive conductor and the sensor and the rest of the low voltage electronics by means of galvanic isolation.
  • the 220 VAC line can be continuously measured and dynamic/pulsing apparatuses and loads L can then be monitored except for static periods of load L.
  • Fig 8 shows an example where a pulsing load is shown.
  • the switch- disconnector function FB can be dynamic and depend on external conditions that vary, for example temperature, pressure, numbers of revolutions and be formed by a thermostat, a pressure switch or a similar detector, that controls the switch-disconnector BL.
  • T for example t2-t ⁇ in Fig 7
  • data and time information about pulse, pause and pulse-pause cycles may be acquired and stored in MC, inter alia minimum and maximum time periods.
  • k(L) k(L)
  • the parameter k(L) can for example be time, but also other entities such as current, voltage, effect, energy etc. can be calculated and used for this purpose. Further, values for average, median, distribution and other statistic variable and properties, over short as well as long time periods, for example the time period T, and a plurality of such time periods may be included. Characteristics and signatures can then be formed by a collection of a plurality of calculated and compound data.
  • ST is also provided with a manual reset button RST for de occasions when the user whishes to manually restart the unit/the timing.
  • Effect and energy consumption can be calculated, if the timer ST is provided with components T for measuring the line voltage that is coupled to another ADC channel (not shown). Such calculated values are presented via the MMI-interface.
  • Fig 9 shows a simplified flow chart of the control program SP.
  • the control program starts after ST has been connected to the 220 VAC-line and MC has run through its start-up phase, PON (Power On).
  • SP initiates its primary memory, among other things it is ensured that the relay is inactive, that all timer registers and variables are reset, and that the line status is set to be connected, i.e. synchronously with the relay.
  • control program SP starts to run through its proper task to control the closing of the electric current circuit dependent on input data from the detector, e.g. the current sensor CS, the man-machine interface MMI, the timer functions TF (timers) or the statistics function SF, which also can perform data collecting, storage, calculations, comparisons and matching.
  • these tasks are executed at different intervals dependent on their priority, for example measurement data and timer values should be taken care of quickly and often whereas calculations and interaction with the user can occur less often and when there is idle time available in MC.
  • This status information is then used when the decision rules are applied to check if the 220 VAC line must be controlled in some way, i.e. be interrupted or closed.
  • ST may be provided with means for communication via the 220V AC line in order to enable presentation of interaction, settings, data and statistics on a graphical user interface, for example by means of a web browser.
  • a simple web server is integrated in ST, as well as components for communication, for example XlO and a power line (220 VAC) modem.
  • the unit may also have a battery for backup and fro driving a real time clock.
  • the invention is here shown for a single-phase voltage supply line but it can of course be generalized, for example to a three-phase voltage system.
  • ST is not limited to being a separate unit.
  • the principle can also be integrated directly in an apparatus, for example a percolator, flat-iron etc. It can also be integrated directly in a socket.
  • a very big advantage with the simple embodiments in Fig 1-4 is that they do not require a current sensor, which is a fig. 1 -4, which is a relatively expensive component, and that the production costs can be kept at a low level.
  • ST can then also be used with dynamic/pulsing loads, but when the time T has passed ST must be reset manually with the reset button RST. Alternatively, ST is automatically reset after a certain, relatively long time.
  • Alternative embodiments can realize the functionality in ST fully in hardware, i.e. without an (integrated) microcomputer.
  • the timing can be performed with integrated circuits (IC) such as the well known timer 555.
  • IC integrated circuits
  • Such embodiments will be described in more detail in conjunction with Fig 10. They are intended to monitor and control static as well as dynamic loads.
  • Fig 10 describes further embodiments.
  • the present embodiments of the invention concerns a device for apparatuses connected to electric power and being devised for detecting and turning power-off or power-on, when the time period for power-off or alternatively for power-on exceeds the preset values of a timer unit.
  • the present invention seeks too solve this problem in a simple manner and in the same time solve further problems that up to now have been un-solved, for example the following water pump problem.
  • a common water pump in a private house, normally pumps up pressure in the water line and when the correct pressure has been attained the pump turns off.
  • the pump starts anew. If for example a water tap has accidentally been left open or if leakage arise, the results is that the pump will run much to often and for too long, which can entail water damages etc.
  • the pump will also start and stop all the time, if the hydrophone or the pressure tank loses too much air pressure. This will damage the pump and consume unnecessarily much electricity, and will render a worse water flow.
  • the present invention aims to reduce the risks for the occurrence of such breakdowns by means of a time monitoring programmable function, for primarily monitoring the time when the apparatus is disconnected.
  • This monitoring shall normally nor affect the function of the pump or the connected apparatuses, neither require any other consideration or setting for using the pump or the connected units as usual after the first programming has been set by the timer units 4 and 6.
  • the invention can be used to monitor or be connected to other types of appliances, for example a flat-iron, a toaster, a radiator or a percolator. All these examples are per se controlled by a detector that is able to disconnect or connect the apparatus, but faults can occur that may cause a fire and for all these types of function the invention is used in accordance with the aforementioned example.
  • Another example of use is when the invention is set to monitor for example a water boiler.
  • Such an apparatus shall bring water to boiling and thereafter turn off the power to the boiler when the water has reached the correct temperature.
  • These kinds of apparatuses are often involved in accidents due to e.g. boiling to dryness and overheating because the thermostat has not disconnected as it should etc.
  • the present invention can also be used for this kind of devices, in which connection also stoves can be mentioned since they cause about 40 % of all fires.
  • the time which the apparatus may be connected is preset, e.g. the time it takes to bring a full boiler to boiling with addition of a couple of minutes. If this time is exceeded the monitoring safety switch turns of the apparatus.
  • the timer unit in the device is reset and next time the boiler or the stove can be turned on anew without any need for any settings on the monitoring safety switch, since it will give a new time period of operation with the original setting as long as everything operates normally.
  • Another simple example of usage of the invention is a monitor for an ordinary lamp.
  • the invention can be used as a monitor for the time period the lamp is allowed to burn and thereafter turn off the power to the lamp after a period if warning intermittent power supply.
  • the lamp can thereafter be lit again with the ordinary switch after the switch has been turned off and thereafter turned on again, whereafter a new full time period of illumination is available without any need for any new setting on the safety switch unit.
  • the invention provides another very unique and practical property, viz that the safety switch itself when connected to a new apparatus can measure the time period for which the apparatus has been connected and how much current the apparatus consumes and has consumed during the time it has been connected.
  • the time the apparatus has been connected can be read-out from a display and by means of this time information it is then easy to set the timer on an appropriate time for which it shall allow a continuous connection of one or a plurality of apparatuses. On the timer, it can also read-out how long the shortest time is that has passed between switch-on and switch-off. In this manner it is easy also to set this time period in cases when this is required, such as in the example with the pump.
  • This function can also be used with flat-irons and other thermostat controlled apparatuses, and then with the addition of a number of switch-on and switch-off occasions that have occurred during a certain period, e.g. half an hour, the number of switch-on and switch-off occasions are registered and presented on the display. If it is then desired that the flat-iron shall be connected at the most for half an hour, a user simply accepts what is presented on the display, whereupon the flat-iron will be switched off after the time period has been attained, because none of the switch-off activities that the thermostat has caused are counted as a cause for reset of the total time period.
  • the invention provides another property, viz that it in one embodiment is designed such that smaller currents that originate from different form of small lamps, having the purpose of indicating that an apparatus is switched on, are allowed to pass but the reset function will nevertheless be executed.
  • This can be illustrated wit a percolator that is set to be connected for e.g. half an hour, whereupon the following happens.
  • the water is boiled and coffee is brewed, and thereafter the power is switched off to this part of the apparatus, but a hot plate with accompanying light emitting diode lamp continues to ⁇
  • the percolator After having connected the safety switch for the first time and having accepted the values for half an hour switch-on, the percolator will be turned off after half an hour. If this happens, the safety switch must be re-started and the old set values will return without any further setting. If, on the other hand, the percolator is turned off before the time has passed, a new time period with automatically be set for half an hour connection without any manual setting.
  • FIG 10 schematically shows a circuit diagram for a device in accordance with the invention in a practically applied embodiment.
  • a supply voltage is input via the lines 7 into a unit 8.
  • two current sensors 1 and 2 measure whether a current is passing dependent in whether a consuming apparatus 3 is connected or not.
  • one of the current sensors 1 and 2 will measure and detect this, and a timing unit 4 is then started.
  • the apparatus 3 is switched off, the current sensors 1 and 2 will detect this, and the timer unit 6 starts when relay 9 is closing. If the time period set for the timer unit 6 runs out before the apparatus 3 is switched off, this will result in that the timer unit 6 resets the timer unit 4 whereupon there will be a new full time period the next time the apparatus 3 is started.
  • the timer unit 4 will continue counting whereas the timer unit 6 is reset at switch-on. If none of the pauses of the apparatus 3 is longer than the set time period of the timer unit 6, the time period of the timer unit 4 will eventually run out whereupon the power to the apparatus 3 is disconnected via relay 5. If any of the pauses exceeds the time period set for the timer unit 6, a reset of the timer unit 4 with a new full time period will occur.
  • This embodiment is intended to work if it would be coupled, as mentioned earlier in the introduction, to control a water pump, having a switch-on and switch-off controlled by a pressure switch.
  • the timer unit 4 starts, when the pump stops the timer unit 6 starts if the pump is inactive for a longer time than the timer unit 6 is set for the timer unit 4 is reset and water can be tapped for yet another full time period, e.g. ten minutes. If the pause of the pump for all this time would never exceed the time for which the timer unit 6 is preset, it will never reset the timer unit 4. The timer unit 4 will then inactivate the pump after some further sequences which will be closer described in the following.
  • the unit 8 In order to be able to easily restart the pump if it has been tuned off, (which could be desirable e.g. taking a shower or watering a flowerbed when the water is shut down) the unit 8 is equipped with a function which can restart the pump according to the following. Before a definite shut down the unit 11 will turn the pump (apparatus 3) off and on a presetable number of times. The person showering will then notice that the water stops running and he may then close the water taps.
  • the test function 11 will, just like in the example above, turn the apparatus 3 on and off for a presetable number of times before the power is fully disconnected to the apparatus 3. In this case the water pressure will not rise again in the water pipes and the pump (apparatus 3) will not be inactive for the period needed in order for the timer unit 6 to lapse. If instead it would pertain to a very small water leakage a restart could occur, but then yet another timer unit 12 could detect if, during a presetable number of times, the timer units 4 and 6 have conducted the same course for a presetable period of time. If that has occurred, an indicator lamp 14 will light up.
  • the invention may be used to monitor e.g. an ordinary lamp in a space if it is desired that it should not be lit for more than a certain period of time or at certain presumptions.
  • the unit 8 could be connected after a common switch 13. When the switch 13 is turned on the lamp (apparatus 3) is lit while at the same time the timer unit 4 starts. When the switch 13 is turned off the lamp is turned off and the timer unit 4 is reset.
  • the lamp (apparatus 3) would not be turned off by the switch 13 after the preset time of the timer unit 4 the power to the apparatus 3 is disconnected whereby the test function 11, as a warning, will turn the lamp on and off a number of presetable times before the power to the apparatus 3 is fully turned off.
  • the timer unit 4 may easily be reset for a new full time period of power to the apparatus 3 by simply switching off the switch 13 in order to switch the switch 13 on again.
  • the timer unit 4 and the timer unit 6 will be reset and a new full time of power to the apparatus is obtained.
  • reset button 10 Yet another possibility for resetting is in the reset button 10, which can be used if it is desired that resetting should not be possible after power failure to the unit 8 whereby a switch 18 in the unit 8 switches on in advance so that this is achieved and no resetting can occur without activating the reset button 10.
  • FIG 10 A detailed description of Fig 10 follows below.
  • the device is characterized by a current sensing device 1 and 2 which detects when and how much current which is consumed by an apparatus 3 above a certain minimum value, whereby a timer unit 4 starts.
  • a timer unit 4 starts.
  • the power to the apparatus 3 is then disconnected, via some kind of organ, pressure guard thermostat or another timer circuit 6 is started which monitors the length of the pause of the apparatus 3. If the preset value of the timer unit 6 is exceeded the timer unit 6 will reset the timer unit 4, which will then anew give the apparatus 3 full time. If the pause of the apparatus 3 should fall below the preset value of the timer unit 6, the time in the timer circuit 4 will not be reset.
  • the timer unit 4 will then continue to progress until the preset time lapses, whereby the apparatus 3 is switched off, via a switch 5. This is registered in a counter unit 15 and a timer unit 16, which will turn the power to the apparatus on and off x number of times with a certain interval. If the unit 3, during this test time, is turned off for a longer time than the preset minimum time, a timer unit 4 will be reset, and a new full time of power to the apparatus will occur. Associated with the unit there is another counter unit 17, which registers the number of switch ons and offs which have occurred for a certain time during which the apparatus 3 has been connected. If the apparatus is controlled by a thermostat the reset function can disregard the switch off of the thermostat, which is regarded as natural.
  • the user may therefore in such cases choose to accept these switch offs for a certain preset time, whereby the safety switch may still be working normally, that is if the apparatus is tuned off within a preset time, the timer unit 4 will be reset, in order to give a new full time the next time the apparatus 3 is turned on.
  • a timer unit 18 may be activated in the cases where a thermostat is connected. This unit is set on a very short time depending on the time which has been shown on the display of the apparatus 3. Each time the thermostat switches off the power to the apparatus 3 the timer unit 18 will be reset.
  • the timer unit 18 will continue until the set time is exceeded whereby the timer unit 18 turns off the power to the apparatus 3 via the switch 5. If the apparatus 3 is turned off before the timer unit 4 has lapsed the timer unit 6 will when this time has lapsed reset the timer unit 4 whereby a new full time can b obtained for the apparatus 3 as soon as it is connected again, which is then detected by the units 1 and 2.
  • the timer unit 4 is reset whereby a new full time is obtained. This does however not occur if the switch 20 is activated since in this case a restart would only be possible by activating the reset button 10.
  • a test function 11 is provided which is connected after the timer unit 4 has lapsed, whereby the test function 11 connects and disconnects the power to the apparatus 3 for a presetable number of times.
  • the timer unit 6 registers, by the current sensor devices 1 and 2, if the apparatus 3 is turned off or not and no longer consumes power. If that does not happen the timer unit 6 is reset and starts the counting. If the power to the apparatus 3 is not consumed during the time for which the timer unit 6 is preset the timer unit 4 is reset and thereby new full time can be given to the apparatus.
  • a time and counter unit 15 which, after a presetable number of times, may warn by a lamp 14 and report the number of times, and/or turn off the power via the timer unit 4.
  • thermostat e.g. a percolator with a heating plate, or a flat-iron
  • the flat-iron is connected to ST and then it takes a while for it to get heated.
  • the power is thus turned on for rather long before the temperature has risen enough for the thermostat to switch off. But from now on the flat-iron will be connected only for short intervals between the switching on and off by the thermostat.
  • the time period 6 will run out after its set time of 2 minutes, whereupon the time period 4 will be reset and a new time period of 30 minutes is given the next time the flat-iron is connected.
  • the power to the load shall be disconnected.
  • This function could then be handled by another timer unit that here is called protective time period 20.
  • This timer circuit shall only be in operation when apparatuses with a thermostat are connected. For example in a water boiler it is not feasible to use this function, which then must be enabled to be switched off.
  • the safety time period (protective time period) 20 shall be switched on. It is then conceivable that the time period 6 starts the safety time period 20 when the time period 6 is reset. The time period 6 starts after the load has been disconnected for the first time, thereafter the time period 6 is reset when the load is connected again. In connection with this reset of the time period 6 the safety time period 20 may also be started. When the thermostat then again disconnects the power the time period 6 is started whereas the time period 20 is reset. If the thermostat of the flat-iron would catch and not switch off, the following will happen. The time 20 is started when the load is connected, and if the load is not disconnected within the preset time for the safety time period 20 it switches of the power via relay 5 to the load 3.
  • the invention is not confined to one of the shown embodiments, but naturally they can be combined with each other in different manners.
  • Fig 11 Such a combination is shown in Fig 11 where the detector D as well as the current sensor CS can be connected to MC.
  • the output signals ul(t) and u2(t), respectively, may then for example be connected to one analogue-digital converter channel each, ADCl and ADC2 respectively, in order to better analyzing different types of operating cases of the load and its characteristics.
  • the safety switch ST may be reset with an on-off cycle of the switch-disconnector BL of the apparatus L without having to activate the reset button RST of the ST.
  • Fig 12 shows another embodiment where two timers are used. The first one will start when the load is activated - BL connects, and the second will start when the load is deactivated - BL disconnects.
  • the safety switch can be programmed so that a pulsating load, e.g. a thermostat, has to disconnect the load under certain conditions in order for the safety switch not to switch off. In this manner several error modes may be detected, e.g. that a thermostat shows a dynamic course with pulses and pauses, and makes the safety switch more universal.
  • One embodiment of the invention is connected to or integrated with a transformer and functions in the following manner.
  • a load L on the transformer is turned off the transformer winding is out of power.
  • a certain constant resistance is always detected when the load is connected.
  • the detector signal registers a completely different and much lower resistance, whereby the relay RE receives a signal to close and give power to the transformer coil.
  • a current sensor placed in a suitable position in the unit senses when the load is disconnected, whereby the relay RE disconnects the voltage to the transformer winding.
  • Some embodiments of the invention are adapted for a connected load in an apparatus which always requires power in order to work.
  • For the safety switch to work in such situations which may for example be thermostat controlled units or where there is some kind of low voltage equipment with a transformer, or just a light diod indicating that an apparatus receives power and is turned on, e.g. a heating element.
  • the detector detects that there is no complete interruption in the detector circuit, a signal is then input to relay RE to actuate it to close and enable supply voltage to the load L. If the load L is not switched on via FB or BL the current sensor will not (as is otherwise the case) detect that a current is passing. This will be registered by MC as an indication of the fact that a load is connected that always require current to the load. When the load L later is switched on at BL by relay RE, this is registered in MC that this is a case where the load continuously needs power, and relay RE will therefore not disconnect the power to the load the next time the load is switched off by BL.
  • the time period T and pause periods are registered by MC as usual, in order to perform the task and switch off or enable a new full time period T, according to predetermined set time periods T max and pause period P. If the safety switch is running out of power or is reset, the control program in MC returns to start anew with checking, by means of the detector signal, if there in a connected load is a full interruption in the circuit into which the load is connected, or if there is a "small" interruption which is registered by means of the detector signal. When there is an interruption with a certain resistance the relay RE will receive continued instruction from MC to supply power to the load via relay RE. Alternatively, a complete interruption is registered and then connected load will remain powerless, as in earlier described embodiments. Alternatively, a transformer is connected or integrated according to an earlier described alternative, and in such an application the transformer coil will remain powerless despite the detected "small" interruption that is registered by the detector signal.

Landscapes

  • Emergency Alarm Devices (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

L'invention concerne un interrupteur de sécurité (1) qui comporte : un premier contact conçu pour une connexion à une source de courant; un second contact conçu pour une connexion à un appareil électrique; un interrupteur conçu pour fermer ou rompre un couplage galvanique, agencé entre lesdits premier et second connecteurs; un capteur de courant étant conçu pour détecter et émettre un signal de détection en fonction fermeture ou non d'un circuit de courant électrique à travers un appareil électrique connecté audit second contact, et un dispositif de commande étant configuré pour commander ledit interrupteur afin de fermer ledit couplage galvanique en fonction d'un signal de détection provenant du capteur de courant.
PCT/SE2009/050298 2008-03-20 2009-03-20 Interrupteur de sécurité WO2009116949A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
SE0800667-8 2008-03-20
SE0800667 2008-03-20
SE0802598A SE532508C2 (sv) 2008-03-20 2008-12-17 Säkerhetstimer
SE0802598-3 2008-12-17

Publications (1)

Publication Number Publication Date
WO2009116949A1 true WO2009116949A1 (fr) 2009-09-24

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Application Number Title Priority Date Filing Date
PCT/SE2009/050298 WO2009116949A1 (fr) 2008-03-20 2009-03-20 Interrupteur de sécurité

Country Status (2)

Country Link
SE (1) SE532508C2 (fr)
WO (1) WO2009116949A1 (fr)

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Publication number Priority date Publication date Assignee Title
CN106209050A (zh) * 2016-08-19 2016-12-07 德力西电气有限公司 一种低成本低功耗的电子开关电路
WO2020025241A1 (fr) * 2018-08-03 2020-02-06 Siemens Aktiengesellschaft Équipement de commutateur de protection pour une machine électrique et utilisation d'un équipement de commutateur de protection de ce type
WO2020106404A1 (fr) * 2018-11-19 2020-05-28 Dedicated2Imaging, Llc. Circuit de temporisation pour système d'imagerie par rayons-x
CN111897260A (zh) * 2020-07-28 2020-11-06 宁波海贝电器有限公司 一种防止干烧的定时器

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US4493983A (en) * 1980-02-01 1985-01-15 Taggart Russell H Current detector in combination with an electrical apparatus
DE19740611A1 (de) * 1997-09-12 1999-03-18 Erkki Telamo Verfahren und Anordnung zum Unterbrechen der Stromversorgung für eine elektrische Belastung
US20020130123A1 (en) * 2001-03-07 2002-09-19 Helmut Prager Device for detecting, monitoring and controlling the operating status of an electric iron
DE10209043A1 (de) * 2002-03-02 2003-09-18 Hartmut Claus Sicherheitsschalter für elektrische Geräte
US20030218846A1 (en) * 2002-02-20 2003-11-27 Erkki Telamo Safety device for a delta-connected three-phase electric appliance
AU2004218710A1 (en) * 2004-10-11 2006-04-27 Janine Fay Lempa Water Saving Pump Timer

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US4493983A (en) * 1980-02-01 1985-01-15 Taggart Russell H Current detector in combination with an electrical apparatus
DE19740611A1 (de) * 1997-09-12 1999-03-18 Erkki Telamo Verfahren und Anordnung zum Unterbrechen der Stromversorgung für eine elektrische Belastung
US20020130123A1 (en) * 2001-03-07 2002-09-19 Helmut Prager Device for detecting, monitoring and controlling the operating status of an electric iron
US20030218846A1 (en) * 2002-02-20 2003-11-27 Erkki Telamo Safety device for a delta-connected three-phase electric appliance
DE10209043A1 (de) * 2002-03-02 2003-09-18 Hartmut Claus Sicherheitsschalter für elektrische Geräte
AU2004218710A1 (en) * 2004-10-11 2006-04-27 Janine Fay Lempa Water Saving Pump Timer

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106209050A (zh) * 2016-08-19 2016-12-07 德力西电气有限公司 一种低成本低功耗的电子开关电路
CN106209050B (zh) * 2016-08-19 2023-08-04 德力西电气有限公司 一种低成本低功耗的电子开关电路
WO2020025241A1 (fr) * 2018-08-03 2020-02-06 Siemens Aktiengesellschaft Équipement de commutateur de protection pour une machine électrique et utilisation d'un équipement de commutateur de protection de ce type
WO2020106404A1 (fr) * 2018-11-19 2020-05-28 Dedicated2Imaging, Llc. Circuit de temporisation pour système d'imagerie par rayons-x
CN113038883A (zh) * 2018-11-19 2021-06-25 专用成像有限责任公司 用于x射线成像系统的计时器电路
US11872072B2 (en) 2018-11-19 2024-01-16 Siemens Medical Solutions Usa, Inc. Timer circuit for X-ray imaging system
CN111897260A (zh) * 2020-07-28 2020-11-06 宁波海贝电器有限公司 一种防止干烧的定时器

Also Published As

Publication number Publication date
SE532508C2 (sv) 2010-02-09
SE0802598L (sv) 2009-09-21

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