Patent Application
20080057453
Referring to
The control box 10 can be provided with a plurality of ignition and flame detecting connecting ports 51 to connect the controller for re-ignition with an ignition and flame detecting probe 100 on each of a plurality of burners, the control box 10 is provided on its other end with electronic connecting ports 52 to communicate the controller for re-ignition with each igniting switch 101 of a gas combustion device, the electronic connecting ports 52 further connect the controller for re-ignition with the power supply 60 and a main gas supplying valve 102, or communicate and integrate with other electronic devices.
Further referring to
Wherein an electric supply 60 has two connecting ends AC-L and AC-N, while an ignition control unit 20 has a rectifying voltage stabilizer 21 for rectifying and stabilizing electric power put out from the AC-L end of the electric supply 60 to DC12V, a first relay 22 connected to the rear end of the rectifying voltage stabilizer 21, a controller 23 for switching the state of operating of the first relay 22 and an idling protecting device 24; wherein the rectifying voltage stabilizer 21 is composed of a capacitor C2, a diode D2, a diode D3, a resistant R3, a Zener diode ZD1 and a capacitor C3; the controller 23 is composed of an NPN transistor Q2 and an NPN transistor Q3; we can see from comparison of
And wherein an idling protecting device 24 is composed of a resistant R2, a resistant R4 and an NPN transistor Q1, the idling protecting device 24 is used to prevent the Zener diode ZD1 from damage by bearing overlarge electric current when in an idle state of the first relay 22.
An ignition activating unit 30 has therein a voltage multiplier 31 for voltage multiplying an output electric power source provided by the first relay 22, a diode D1 connected to the rear end of the voltage multiplier 31, a resistant R1 connected to the rear end of the diode D1, an electric storage and discharge device 32 connected to the rear end of the resistant R1 and a voltage supercharger 33 connected to the rear end of the electric storage and discharge device 32 and connected with the ignition and flame detecting probe 100; the voltage multiplier 31 is composed of a capacitor C1 and a diode D5, the electric storage and discharge device 32 is composed of a capacitor C4 and a fast thyrister SDIAC.
A flame detecting unit 40 integrates therein a flame detecting and ignition control path, and connects respectively with the ignition and flame detecting probe 100 and the ignition control unit 20; wherein the flame detecting path is for coupling of the electric supply 60 through the capacitor C6 to provide voltage for the ignition and flame detecting probe 100 via the resistant R8, a grounding end is provided between the resistant R8 and the ignition and flame detecting probe 100 for detecting whether a flame exists on a burner; one end of the ignition control path is connected with the above mentioned controller 23, its other end is connected with the igniting switch 101; the ignition control path further includes an NPN transistor Q4.
Cooperation of the ignition control unit 20, the ignition activating unit 30 and the flame detecting unit 40 renders that when the igniting switch 101 is turned on while there is no flame on a corresponding burner, the corresponding ignition and flame detecting probe 100 starts to discharge with high voltage for ignition, so that the burner can release gas for burning; and that if extinguishment occurs during the process of burning on the burner, by detecting of the ignition and flame detecting probe 100 and an action of re-ignition, the burner burns again.
A time control unit 70 is provided having a function: when the action of re-ignition fails for a predetermined time, the controller for re-ignition will shut the main gas-supplying valve 102 and stop any igniting or re-igniting action.
When the igniting switch 101 is turned on, an emitter of an NPN transistor BQ4 and an emitter of an NPN transistor Q2 can be connected to the igniting switch 101 via a diode BD3 to get a grounding signal, if at this time the predetermined overtime set by the time control unit 70 has not been reached, a supply voltage VCC can be connected to a base of the NPN transistor BQ4 via a resistant R10, thus the NPN transistor BQ4 can control the action of a second relay 71 to keep opening of the main gas-supplying valve 102, meantime, the NPN transistor Q2 can control the action of the first relay 22 in favor of ignition of the ignition and flame detecting probe 100.
Within the predetermined overtime, if the burner presents the state of re-ignition, the NPN transistor Q4 will be cut to be in its close state, a collector of the NPN transistor Q4 connects a terminal at the supply voltage VCC and the Zener diode BZD1 to a base of an NPN transistor BQ1 via a resistant BR1, meantime, the terminal at the supply voltage VCC can be connected via a resistant R9 to the Zener diode BZD1 and via the resistant BR1 to the base of an NPN transistor BQ1 via a resistant BR1; now the NPN transistor BQ1 is in its open state, hence an NPN transistor BQ2 is in its close state, thereby a PNP transistor Q3 and the NPN transistor Q2 are both in their close states, thus the first relay 22 is inactive, and the controller for re-ignition stops the action of re-ignition. At this time, by the fact that the NPN transistor BQ1 is in its open state, an NPN transistor BQ7 is in its close state, while an NPN transistor BQ6 is in its open state, hence a capacitor BC2 can keep its state of grounding and discharging, thereby an NPN transistor BQ5 is in its close state, and the NPN transistor BQ4 is still in its open state, thus the second relay 71 keeps opening of the main gas-supplying valve 102.
When the action of re-ignition fails and the burner is unable to burn again, electric current at the connecting end AC-L of the electric supply 60 can flow through a resistant R14 to a base of the NPN transistor Q4, then the NPN transistor Q4 is triggered to be in its open state, now the collector of the NPN transistor Q4 will output voltage with a lower potential to the Zener diode BZD1, and to the base of an NPN transistor BQ1 via the resistant BR1, thus the NPN transistor BQ1 is in its close state, and thereby the NPN transistor BQ2 is in its open state to make the PNP transistor Q3 and the NPN transistor Q2 both in their open states. So that the first relay 22 is activated to make continuous discharging and igniting of the ignition and flame detecting probe 100; when the action of continuous discharging and igniting exceeds a predetermined time, the NPN transistor BQ1 is in its close state, and an NPN transistor BQ7 is in its open state, while the NPN transistor BQ6 is in its close state; and by virtue that the NPN transistor BQ2 is in its open state, thereby the NPN transistor BQ3 is in its open state too, a collector of the NPN transistor BQ3 can output voltage with a higher potential through a resistant BR6 to do electric charging for the capacitor BC2; when the capacitor BC2 is charged to a predetermined value, an NPN transistor BQ5 is in its open state, hence the NPN transistor BQ4 is in its close state, and the second relay 71 is turned off to shut the main gas-supplying valve 102. When the NPN transistor BQ5 is in its open state, the NPN transistor Q2 can also be cut to be in its close state, so that the first relay 22 is turned off to stop ignition of the ignition and flame detecting probe 100.
In other words, when the combustion gas at the burner can not be ignited or fire is extinguished in the middle of operation, the main gas-supplying valve 102 still can keep its open state to supply the gas, when the re-igniting action keeps on to exceed A, a predetermined time and there is no fire ignited, the controller for re-ignition will stop gas supplying of the main gas-supplying valve 102, and stop the re-igniting action, a safe interruption effect is obtained. For example: when the re-igniting action keeps on for 30 seconds and the burner does not reach the state of ignition, the main gas-supplying valve 102 is turned off and stops the re-igniting action at the same time. After inducing the safe interruption effect, the igniting switch 101 shall be turned off before it is activated again, thus the state of safe interruption can be relieved.
As shown in
As shown in
The mode of operation of the time control unit 70 is: a capacitor BC2 at the burner in a normal burning state is charged to a saturation state, and when in the action of igniting or re-igniting, the capacitor BC2 will discharge to a resistant BR5, and after a period of time, when discharging of the capacitor BC2 makes its voltage insufficient, an NPN transistor BQ5, an NPN transistor BQ3 and an PNP transistor Q3 will be in their close state; and the first relay 22 and a second relay 71 are turned off to stop igniting and re-igniting and to close a main gas-supplying valve 102, and a safe interruption effect is obtained.
The preferred embodiment shown and described is only for illustrating the present invention, and not for giving any limitation to the scope of the present invention; it will be apparent to those skilled in this art that various modifications or changes without departing from the spirit of this invention shall also fall within the scope of the appended claims.
