JPH0125894Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a bathtub in which the ignition and extinguishment of a burner are controlled by repeated pressing of a push-button switch, that is, by pulses.

Conventionally, the ignition and extinguishing of the burner in a bathtub have been performed using a push button switch, and the pulses output by the switch operation are input to an inverting circuit such as a flip-flop circuit to reverse the circuit, thereby burning or extinguishing the burner. I try to make it possible. The reason for controlling with the above pulse is that if the switch is an ON-OFF type, if the main power is turned ON and OFF while the switch is ON, there is a risk that the burner will be ignited by mistake even though there is no water in the bathtub. It's for a reason.

However, even with the above-mentioned pulse type switch, if the switch itself becomes welded and shuts down, the above-mentioned ON-
The same problem as with an OFF type switch will occur.

The present invention is intended to solve the problems of the prior art described above, and will be specifically explained below based on an embodiment shown in the drawings.

Reference numeral 1 designates a load circuit that opens and closes gas valves and the like to control the burner to blink. 2 is a microcomputer,
3 is a push button type switch. The switch 3 is connected in series between the resistor 4 and the power supply line, the midpoint 5 of the two is connected to the base of a transistor 6, and the collector of this transistor 6 is connected to the microcomputer 2.
It is connected to input terminal 7 of. 8 is the output terminal,
It is connected to the load circuit 1 via an inverter 9 and a transistor array 10. In this embodiment, the microcomputer 2 is used as an inverting circuit, and the flag of the microcomputer 2 (hereinafter referred to as
It is written as FG. ), as shown in Figure 2, if the input from input terminal 7 rises, it will rise after a certain period of time, and if the input falls, it will fall after a certain period of time.
FG1 is set to be inverted when FG0 falls, and a low combustion command signal is output from output terminal 8 when FG1 rises.

As mentioned above, the reason why FG0 is delayed for a certain period of time with respect to input changes is to prevent erroneous operation by receiving the signal as a signal only when the input continues for a certain period of time.

In the above configuration, when the power is turned on, the FG in the microcomputer 2 is in the falling state (=
0). At this time, the transistor 6 is in a cut-off state, so the input from the input terminal 7 rises (=1), and therefore FG0 also rises after a certain period of time.
(=1) When the switch 3 is pressed to perform combustion, the transistor 6 becomes conductive and the input from the input terminal 7 falls (=0), and in response to the fall of the input, FG0 also falls (=0). On the other hand, FG1 is reversed and becomes a rising state (=1), and a combustion command signal is output from the output terminal 8. (Fig. 3) When the switch 3 is released after combustion, the transistor 6 is cut off and the input and FG0
becomes the rising state (=1) again, but FG1 does not reverse and combustion continues.

If you want to extinguish the fire next time, press the switch 3 again. At this time, as in the case described above, FG0 falls (=0), so FGI is inverted and becomes a falling state (=0), and a command signal for extinguishing the fire is output from the output terminal 8. (Fig. 3) Next, when the switch 3 is fused and enters the short state, the input will not rise even if the power is turned on, and FG0 will not rise. In other words, since FG0 never falls, FGI
is never reversed from its initial state, and therefore no combustion command signal is output. Furthermore, even if switch 3 is destroyed in an oven state, the input will not fall, so FGI will not be reversed either.

As described above, according to the present invention, it is possible to provide a control device with excellent safety for the bath kettle, and in the event of a malfunction of the switch, combustion can be reliably prohibited, thereby achieving the above-mentioned safety. can be further improved.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram showing an embodiment of the present invention;
FIG. 2 is an explanatory diagram of the same, and FIG. 3 is a flowchart of the same. 2...Inversion circuit (microcomputer), 3
...Switch.

Claims (1)

[Scope of utility model registration request] In a device in which the output of an inverting circuit is reversed by pressing a push-button switch for both turning on and off, thereby causing the burner to blink, the reversing circuit receives a falling pulse generated by pressing the switch;
A control device for a bathtub, characterized in that the falling edge of the falling pulse is detected and the output is inverted.