JPS6222368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion safety device for a combustor using gas or liquid fuel.

In conventional combustors, when vibration is applied to the combustor due to an abnormality such as an earthquake, a seismic sensor is activated to cut off power supply to the control circuit of the combustor in order to stop combustion. If this seismic sensor is activated, it is necessary to check the effect of the vibration on the combustor and restart post-combustion.For this reason, with conventional devices, the power must be turned off by unplugging the power plug from the outlet, etc. This prevented combustion from restarting.

However, in such conventional examples, if the seismic sensor is deactivated and the operation switch is turned on during a power outage, combustion will restart as soon as the power is restored, which poses a safety problem. When used in a pot, there is a risk of accidentally heating the pot empty, which also poses a safety problem.

The present invention eliminates the drawbacks of the conventional example described above, and embodiments thereof will be described below with reference to the accompanying drawings.

Reference numeral 1 denotes an operation switch, which is supplied with power via a power switch (not shown). 2 is a transistor whose emitter and collector are connected in series to the power supply line after the operation switch 1; 3 is a combustion control circuit for operating the combustor in a predetermined sequence; 4 is a PNP type second transistor connected between the power supply lines before the operation switch 1, and a switch 5 is connected to the collector side of the second transistor 4, which is opened when an abnormality occurs, for example, when a seismic sensor is activated; The base of a first NPN transistor 6 is connected in series with the switch 5. The collector of the first transistor 6 is connected to the bases of the transistor 2 and the second transistor 4, and the emitter side is connected to the ground side power supply line.
The transistor 6 is cut off in the event of an abnormality to cut off the power supply to the combustion control circuit 3. Also second
The base of the transistor 4 is connected in parallel with the first transistor 6 through a resistor 7 to a circuit 8 that leads to the ground side power line, and the ground side of the resistor 7 of the circuit 8 is connected to the power line after the operating switch 1 and the circuit. It is connected at 9. The seismic sensor is of an automatic return type, and the switch 5 is automatically closed when normal conditions are reached. Further, the switch 5 is not limited to a switch for a seismic sensor, but may be a high limit switch that is activated in the event of overheating, as long as it is opened in the event of an abnormality.

Next, the operation of the embodiment will be explained. When a power plug (not shown) is inserted into an outlet, power is supplied between terminals A and A, and the base current of the second transistor 4 flows from the circuit 8 to the ground power line, making the second transistor 4 conductive. Therefore, the conduction current is supplied to the base of the first transistor 6, and the first transistor 6 also becomes conductive. When the first transistor 6 becomes conductive, the second transistor 4
Since the base current flows between the collector and emitter of the first transistor 6, both transistors 4 and 6
is maintained in a conductive state. Then, turn on the operation switch 1.
, the base current of transistor 2 becomes the first
The current flows through transistor 6, thus making transistor 2 conductive and supplying power to combustion control circuit 3 to cause the combustor to burn in a predetermined sequence.

If a vibration is applied during combustion due to an earthquake or the like, the seismic sensor is activated, the switch 5 is opened, the conduction current of the second transistor 4 is cut off, and the first transistor 6 is cut off. At this time, the operation switch 1 is closed, and the potential at point B on the ground side of the resistor 7 is higher than the potential at point C because the power supply voltage is supplied by the circuit 9. Therefore, the second transistor 4 Since no base current flows through the circuit 8, if the first transistor 6 is cut off, the circuit will be cut off immediately.
Even if the abnormality is cleared and the switch 5 is closed again, the circuit 9 prohibits conduction of the second transistor 4 while the operation switch 1 is turned on as described above, so naturally the first transistor 6 is in a cut-off state, the combustion control circuit 3 is not energized, and combustion is not restarted. Naturally, even if the switch 5 is not provided, combustion will not occur when the operation switch 1 is turned on. .

Therefore, in order to restart combustion, it is necessary to open the operation switch 1, and then the potential at point B drops and the base current of the second transistor 4 flows into the circuit 8.
The first transistor 6 also becomes conductive and combustion becomes possible.

As described in the above embodiments, in short, the present invention provides a transistor whose emitter and collector are connected to the power supply line from the operation switch to the combustion control circuit, and connects the base of the first transistor for driving the transistor and the operation switch. The emitter and collector of the second transistor are connected to the power supply side of the second transistor through a switch such as an automatic reset type seismic sensor, and the base of the second transistor is connected to the collector of the first transistor and the first transistor. According to the present invention, the transistor is connected in parallel to a circuit leading to the ground side power line via a resistor, and the circuit is connected to the power line after the operation switch. According to the present invention, for example, the first transistor If the power is shut off in the event of an abnormality such as this, even if the power goes out during the abnormality and the power is restored, combustion will not be restarted unless the operation switch is operated, which is extremely effective in terms of safety. If the present invention is used to control a bathtub, it will be extremely effective in preventing dry heating due to erroneous operation. Furthermore, according to the present invention, when the first transistor is cut off in the event of an abnormality as described above, the operation switch has the function of a reset switch, so a keep relay or a reset switch can be eliminated, and in this case, parts There is also the advantage that the number is small and the price is low.

[Brief explanation of the drawing]

The drawing is an electrical circuit diagram showing an embodiment of the present invention. 1... Operation switch, 2... Transistor, 3
... Combustion control circuit, 4 ... Second transistor,
5...Switch, 6...First transistor, 9
……circuit.

Claims (1)

[Claims] 1. A transistor with its emitter and collector connected to the power supply line from the operation switch to the combustion control circuit is provided, and the base of the first transistor for driving the transistor and the power supply side of the operation switch are connected to the emitter and collector of the second transistor. In addition, the base of the second transistor is connected to the collector of the first transistor and the ground side power line through a resistor in parallel with the first transistor. 1. A combustion safety device for a combustor, characterized in that the circuit is connected to a circuit leading to the operation switch, and the circuit is connected to a power supply line downstream of an operation switch.