JPH0148799B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an iron that prevents accidents such as fire by cutting off the heater circuit if the iron is left unattended with the power turned off.

BACKGROUND ART Conventionally, there have been some irons that cut off the heater circuit after a certain period of time has elapsed after the iron has been left standing, determining that the user has forgotten to turn off the power. At this time, the time taken to shut off the heater circuit is changed depending on whether the iron is placed horizontally or vertically, achieving both safety and ease of use.

That is, placing the iron vertically is common during use of the iron. In other words, this time is waiting time, not forgetting to turn off the power. Therefore, the time it takes to shut off the heater circuit is longer,
Furthermore, if the heater is left horizontally for a long time, there is a high risk of fire, etc. In this case, the time until the heater circuit is shut off is set short.

FIG. 6 shows the above conventional circuit. Switch SW ₁
is a switch that detects whether the iron is placed horizontally or vertically. When the iron is placed horizontally, SW ₁ is off, a high level voltage is read into the input port I ₁ of the microcomputer IC ₁ , and it is determined that the iron is placed horizontally.

When the iron is placed vertically, SW ₁ is turned on, a low level voltage is read into the input port I ₁ of the microcomputer IC ₁ , and it is determined that the iron is placed vertically.

FIG. 7 shows switch _SW1 . SW ₁ is a mercury switch, and mercury 14 is sealed in a case 16. 15 is the electrode and lead wire, and when the iron is placed horizontally, mercury 14 is the lead wire 1
When the lead wire ₁₅ is placed vertically, the lead wire 15 is submerged in the mercury 14, and SW ₁ is turned on.

When microcomputer IC ₁ determines whether the iron's orientation is horizontal (I ₁ input voltage high level) or vertical (I ₁ input voltage low level), microcomputer IC ₁ performs a timer operation to determine whether the iron is horizontal or vertical. Performs a time count operation for a specified period of time.

Problems to be Solved by the Invention In such conventional technology, the number of pulses of a constant frequency is counted, and when the horizontal state, the number of pulses is small,
When vertical, a large number of pulses were counted, and when horizontal, a short time was obtained, and when vertical, a long time was obtained.

Therefore, two prescribed values are required, one for the horizontal pulse and the other for the vertical pulse, and the circuit becomes complicated and expensive due to the use of a microcomputer, etc.

The present invention solves the above-mentioned problems and provides an iron that achieves the intended purpose with a very simple circuit configuration.

Means for Solving the Problems In order to solve the above problems, the present invention switches the oscillation frequency of the oscillation section by turning on and off the attitude detection switch, counts the number of pulses of the oscillation output, and maintains a constant count number. After reaching the target, it outputs a signal to drive the relay and shut off the heater circuit.

Effects The present invention uses the above-described configuration to detect the posture of the iron by turning on and off the posture detection switch, and at the same time also switches the timer time, and can detect the posture and obtain the timer time according to the posture with a simple circuit configuration. ing.

Embodiment FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an attitude detection switch that is turned on when the iron is placed horizontally and off when it is placed vertically, and 2 is an oscillation section, which switches the oscillation frequency by turning on and off the attitude detection switch 1. A counting section 3 counts the number of pulses output from the oscillation section 2 and outputs a signal to the relay 4 when a certain count is reached.

In other words, if the oscillation frequency of the oscillation section is configured to be high when the iron is placed horizontally and low when the iron is placed vertically, the oscillation frequency will be constant in the count section 3. It takes a short time to reach the count number when the iron is in a horizontal position, and it takes a long time when the iron is in a vertical position. The output signal of the counting section 3 is input to the relay 4 and drives the relay. The contacts of the relay 4 are connected to a heater 5 that heats the base of the iron, and when the output signal of the counting section 3 drives the relay 4 after reaching a certain count, the circuit of the heater 5 is cut off.

Figure 2 shows attitude detection switch 1 used in the present invention.
An example is shown below. 6 is a case, 7 is a ball, and 8 is a photointerrupter.The bottom of the case 6 is high on both sides and low in the center.When it is horizontal, the ball 7 is always in the center of the case and the ball is placed on the photointerrupter 8. 7 is located.

When the iron is placed vertically, the ball 7 is attached to the iron so that it leaves the center of the case 6 and moves to the end of the case 6.

FIG. 3 is a diagram showing the operation of this attitude detection switch 1. A light emitting diode 9 and a phototransistor 10 are provided within the photointerrupter 8.
When the iron is placed horizontally and the bulb 7 is above the photointerrupter 8, the light emitted from the light emitting diode 9 is reflected by the bulb 7 and input to the phototransistor 10, which turns on. The iron is placed vertically and the ball 7 is connected to the photointerrupter 8.
When it is not above the light emitting diode 9, the light emitted from the light emitting diode 9 is not reflected by the bulb 7, so it is not input to the phototransistor 10, and the phototransistor 10 is off.

FIG. 4 shows an embodiment of the circuit of the present invention. In the figure, L ₁ is a light emitting diode, Q _P is a phototransistor, and L ₁ and Q _P are built into the photointerrupter 8, and are elements constituting the attitude detection switch 1 shown in FIG. _R1 is a resistor that limits the current flowing from the DC power source E to the light emitting diode _L1 ,
R ₂ and R ₃ are resistors connected to the phototransistor Q _P.

Now, the operation when the iron is placed in a horizontal position will be explained.

The light emitted from the light emitting diode _L1 is reflected by the bulb 7 and input to the phototransistor _QP , _which turns on. When the phototransistor Q _P turns on, the base current of the transistor Q ₁ flows through the DC power supply E, the emitter of the transistor Q ₁ , the base,
It flows through resistor R ₃ and phototransistor Q _P , turning on transistor Q ₁ .

When transistor Q ₁ turns on, the parallel circuit of resistors R ₄ and R ₅ is connected to capacitor C ₁ , and resistors R ₄ ,
A parallel circuit of _R5 and a time constant circuit of capacitor _C1 are constructed. The oscillation circuit 11 is composed of a resistor and a capacitor, and the oscillation frequency is determined by a time constant circuit composed of the resistor and capacitor. The time constant is τ
Then, it is expressed as τ=R×C, and the capacitor C
Assuming that the capacitance value of is constant, increasing the value of R increases τ and lowers the oscillation frequency. On the contrary, R
When the value of is decreased, τ becomes smaller and the oscillation frequency becomes higher. If the iron is placed horizontally, the resistor connected to capacitor C ₁ is R ₄ , as mentioned above
and R ₅ are parallel resistances, and the oscillation frequency increases with τ = (R ₄ × R ₅ / R ₄ + R ₅ ) × C ₁ .

When the iron is placed vertically, no light enters the phototransistor Q _P , so the phototransistor Q _P is turned off, and therefore the base current of the transistor Q ₁ does not flow and the transistor Q ₁ is turned off. Resistor R ₄ connected to the collector of transistor Q ₁ has
Since transistor _Q1 is off, no current flows,
The time constant circuit consists of resistor _R5 and capacitor _C1 . Therefore, the time constant τ at this time becomes τ=R ₅ ×C ₁ , which is larger than when τ is placed horizontally, and the oscillation frequency becomes lower. The first circuit including this oscillation circuit 11, transistor Q ₁ , resistors R ₄ , R ₅ , and capacitor C ₁
This constitutes the oscillation section 2 shown in the figure. The output voltage e ₀ from the oscillation section 2 is input to the counting section 3.

The operation of the counting section 3 will be explained based on FIG. In the figure, A indicates the output voltage of the oscillating unit 2 when the iron is placed horizontally, and B indicates the output voltage e ₀ of the oscillating unit 2 when the iron is placed vertically. For example, if the standard count number is 5,
Counter 3 when counting 5 e ₀ pulses
A signal is output from and drives the relay 4. When the iron is placed horizontally, the frequency is high, so the time to count 5 pulses is short (see Figure 5A).
t ₁ ), and when the light emitting diode is placed vertically, the frequency is low, so it takes a long time to count five pulses (t ₂ in FIG. 5B). This time t ₁ or t ₂ may be multiplied by a certain coefficient, and after that time a signal may be output from the counting section 3 to drive the relay, or,
In the above example, the prescribed count number is 5, but this can be set to a larger number or conversely to a smaller number to obtain the desired time, and after that time has elapsed, a signal is output from the counting section 3. , can also drive relay 4.

In FIG. 4, the relay coil 12a and the relay contact section 12b constitute the relay section 4 of FIG. V _AC is a power supply, to which a heater 5 that heats the base of the iron and a relay contact part 12 are connected. When the iron is in use, the relay contact part 12 is closed, the heater 5 is energized, and the thermostat 13 The temperature is regulated and it operates normally. When the iron is left in a horizontal or vertical position, pulse oscillation and pulse counting start as described above, and after a predetermined period of time, the relay coil 12
a is driven, the relay contact portion 12 opens, and the heater circuit is cut off. In addition, initially the relay coil 12
Needless to say, the present invention also includes a method in which the relay contact section 12 is closed by passing a current through a, and when the relay contact section 12 is left for a certain period of time, the relay coil current is turned off and the relay contact section 12 is turned off.

Effects of the Invention In the present invention, the output pulse frequency of the oscillation section is switched by the output of the attitude detection switch and inputted to the counting section, and the counting section is set to have a certain prescribed value, and the pulse count number is set to this fixed value. The count unit outputs an output when the timer reaches , and the circuit is configured to drive a relay.It has the advantage of using a small number of circuit elements and a general-purpose timer IC, and is inexpensive and highly reliable. It is possible to provide a safe iron that shuts off the heater circuit after a suitable time depending on the situation.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a sectional view showing an embodiment of the attitude detection switch used in the invention, Fig. 3 is an explanatory diagram of the operation of the position detection switch shown in Fig. 2; 4 is a circuit diagram of an embodiment of the present invention, FIGS. 5A and 5B are explanatory diagrams of the operation of the counting section in FIG. 4, FIG. 6 is a conventional circuit diagram, and FIG. 7 is a diagram of a conventional attitude detection switch. FIG. 1... Attitude detection switch, 2... Oscillator, 3...
...Count section, 4...Relay.

Claims (1)

[Claims] 1. An attitude detection switch that detects the horizontal or vertical attitude of the iron, an oscillation part of this attitude detection switch whose oscillation frequency changes to be high when the horizontal state is detected, and low when the vertical state is detected, and the output of this oscillation part. An iron that includes a counting section that counts the number of pulses and outputs an output after reaching a certain number of pulses, and a relay that is driven by the output of the counting section and shuts off a heater circuit.