JPH0552240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an anron having a function of preventing overheating accidents caused by forgetting to disconnect the power cord.

Conventional technology Conventionally, there has been a technology in which a switch is turned on and off by the reciprocating motion of the iron while the iron is in use, and the signal determines that the iron is in use, or it is determined that the iron is not in use if it is left stationary for a certain period of time without moving. Ta.

FIG. 6 shows a conventional circuit diagram. 1 is a use/non-use detection switch, which turns on and off during use, and input port I ₁ of microcomputer IC ₁ .
When the use/non-use detection switch 1 is on, a low level voltage is read, and when it is off, a high level voltage is read. Input port of microcomputer IC ₁
When the voltage at _I1 remains high or low for a certain period of time, the voltage at the output port _O1 of the microcomputer _IC1 goes from high to low, and the transistor _Q4 changes from on to off.

Also, the output port of microcomputer IC ₁
The voltage of O ₁ remains high until microcomputer IC ₁ counts the specified time.
Q ₄ is on, so relay RL ₂ is on.

If transistor Q ₄ turns off, the relay coil
Since the current flowing through RL ₂ is cut off, relay coil RL ₂ is also turned off. The contacts of the relay coil RL ₂ are connected in series with the power supplies 2 and 3 and the heater 6 that heats the base of the iron, and when the relay coil RL ₂ is turned off, the contacts are also turned off and the current of the heater 6 is cut off. Ru. Therefore, safety is ensured.

When the iron is in use, the voltage at the input port _I1 of _the microcomputer IC1 changes from high level to low level or from low level to high level while the microcomputer _IC1 is counting time.

When the voltage at the input port _I1 changes during time counting, the microcomputer IC ₁ resets the counting time and re-counts the time from zero.

Microcomputer IC ₁ supports the above operations through programming.

Problems to be Solved by the Invention Since such conventional circuits use a microcomputer IC ₁ , program development is required and the development period becomes long, the circuit becomes expensive, and specifications change. It had the disadvantage that it was not easy.

The present invention has been made in view of the above points, and does not use a microcomputer, so no program development is required, and is composed only of hardware.It also has a simple configuration, and can detect whether or not the iron is being used. The purpose is to provide a safe iron that sometimes turns off the heater.

Means for Solving the Problems In order to achieve the above object, the iron of the present invention includes a usage state detection switch section that is turned on and off by the reciprocating movement of the iron body, and an output of this usage state detection switch section. a first differential circuit section that performs differentiation; and a first circuit that is turned on and off by the output of the differential circuit section and that outputs a signal having a predetermined pulse width and a predetermined voltage from the signal output from the differentiator circuit section. The heater is equipped with a switch section, a timer circuit section that is reset by the output of the first switch section, and a second switch section that turns off the heater power supply according to the output of the timer section after a certain period of time has elapsed. be.

Effects According to the present invention, with the above-described configuration, only the change in the output voltage of the usage state detection switch section is detected by the differentiating circuit section, and the timer circuit section is reset.
When the output voltage of the usage state detection switch section is maintained at a high level or a low level, the timer circuit section is not reset and performs a time counting operation.

In other words, when the iron is left unused and left unused, the output voltage of the usage state detection switch will remain at a high or low level, and after a certain period of time, the heater circuit will be shut off. do.

When using the iron, the usage state detection switch turns on and off due to the reciprocating movement of the iron, and the output voltage of the usage state detection switch section changes from high level to low level, or from low level to high level. , the change is obtained as the output of the differentiating circuit section.The output voltage of this differentiating circuit section is used to reset the timer circuit section, and the timer circuit section is cleared each time there is a change, so the heater circuit section is not cut off. , the iron is kept at the working temperature and can be used for ironing.

Embodiment An embodiment of the present invention will be described based on FIG. In FIG. 1, reference numeral 1 denotes a usage state detection switch section which is turned on and off by the reciprocating movement of the iron body.By turning this usage state detection switch on and off, a low level or high level output voltage can be obtained.

2 is a differential circuit section, and a usage state detection switch section 1
Detects the change in output voltage. Reference numeral 3 denotes a first switch section, which changes from off to on or from on to off depending on the output voltage of the differentiating circuit section 2. 4 is a timer circuit section, which is reset by the output voltage of the switch section 3; That is, when there is no voltage from the switch section 3, the timer circuit section 4 counts time and outputs a voltage for driving the second switch section 5 when a certain value is reached. When the voltage is output from the switch section 3, the timer circuit section 4 is reset and the time count is cleared.
Count the time again from zero.

Reference numeral 5 denotes the second switch section described above, and when it is turned on, power is supplied to the heater 6 to heat the iron base.

When the second switch section 5 is turned off, the power supply circuit of the heater 6 is cut off, and the power supply to the heater 6 is stopped.

The second switch section 5 is turned off when the timer circuit section 4 has counted a specified time, and at this time the timer circuit section 4 outputs a signal to turn off the second switch section 5.

FIG. 2 shows an embodiment of the usage state detection switch 1. As shown in FIG. 7 is the case, 8 is the ball in case 7, 9
is a reflective photointerrupter with a built-in light emitting diode and phototransistor. Case 7 is
The ball 8 in a horizontal state is the photointerrupter 9
When the ball 8 is placed above the photointerrupter 9, light enters the phototransistor and the phototransistor is turned on.

FIG. 3 is a diagram showing the operation of the usage state detection switch 1. When the ball 8 is on the photointerrupter 9, the light emitted from the light emitting diode _L1 is transmitted to the ball 8.
and enters phototransistor _Q1 . Therefore, at this time, phototransistor _Q1 is turned on.
When the iron is placed on the heel rest, the case 7 is in a vertical position, so the ball 8 leaves the photointerrupter 9 and is located at the end of the case 7, and the light emitted from the light emitting diode _L1 is transmitted to the phototransistor _Q1. Since there is no input to the signal, phototransistor _Q1 is turned off. In addition, when the iron is in use, the ball 8 is moved to the case 7 in order to make the iron body reciprocate.
The phototransistor _Q1 turns on and off repeatedly.

FIG. 4 shows a concrete example of the circuit, and FIG. 5 shows its voltage waveform diagram.

In FIG. 4, the portions 1 to 6 surrounded by broken lines correspond to the portions of the block diagram in FIG. 1.

That is, in Fig. 4, reference numeral 1 is a usage state detection switch section, which flows a specified current from a DC power supply E through a resistor _R1 to a light emitting diode _L1 .
Light up L ₁ . Q ₁ is a phototransistor that detects the light from light emitting diode L ₁ . R ₂ is the load resistance of phototransistor Q ₁ , and the collector voltage _{V 1 of} phototransistor Q ₁ is
When it is on, it is low level, and when it is off, it is high level. 2 is a differentiating circuit section having a capacitor C ₁ and a resistor R ₃ , and the output voltage V ₂ of the differentiating circuit section shows the amount of change when the voltage V ₁ changes from low to high or from high to low. .

Reference numeral 3 denotes a first switch section, which is composed of a transistor Q ₂ and a load resistor R ₄ . If transistor Q ₂ is turned on, the collector voltage of transistor Q ₂ V ₃
is low level, and if off, _V3 is high level. 4 is a timer circuit section;
If the input voltage _V3 remains at a high level, the timer circuit will not be reset.
Performs time count operation. During time counting, the output voltage _V4 of the timer circuit section 4 is at a high level. When the timer circuit section 4 performs a time counting operation for a specified period of time, the output voltage _V4 of the timer circuit section 4 becomes a low level.

When the input voltage V ₃ of the timer circuit section 4 becomes low level, the timer circuit section 4 is reset, and when the input voltage V ₃ returns from the low level to the high level, the time counting operation starts from zero again. . 5 is the second switch part, resistor R ₅ ,
R ₆ , transistor Q ₃ , relay RL, diode D ₁
It's getting more familiar. The contact point of relay RL is heater 6
The device is configured to turn on and off the power supplied to the device. When the input voltage V ₄ to the second switch section 5 is at a high level, the transistor Q ₃ is turned on and the relay
When RL is on, the relay contacts close, power is supplied to the heater 6, and it generates heat. When the input voltage _V4 to the second switch section 5 is low level, the transistor
_Q3 is turned off, relay RL is also turned off, and therefore the contacts of the relay are also opened, power is no longer supplied to heater 6, and heating of heater 6 is stopped.

FIG. 5 shows the voltage waveform of _V1 . Phototransistor Q ₁ is on until time T ₁ is reached, time T ₁
~T ₂ is phototransistor Q ₁ off, T ₂ ~ T ₃ is phototransistor Q ₁ is on, T ₃ ~ _{T 4} is phototransistor Q ₁ is off, T ₄ and after is phototransistor Q ₁
is on.

That is, from time T ₁ to T ₄ , the iron is in use,
Phototransistor _Q1 is turned on and off by the reciprocating movement of the iron body. Since the iron has been left unused since time T ₄ and the movement of the iron is stopped, the movement of the ball 8 of the sensor is stopped and the phototransistor Q ₁ remains on.

FIG. 52 shows the voltage waveform of _V2 . At time T ₁ , phototransistor Q ₁ turns off and voltage V ₁ rises, so that this differential output V ₂ is obtained. The differential output at the time of rising is caused by passing the base current through transistor _Q2 ,
Turn on transistor _Q2 . Therefore, V ₂ is the base-emitter forward voltage V _BE of transistor Q ₂
It doesn't go beyond that. At time _T2 , the phototransistor _Q1 is turned on from off, so the voltage _V1 falls, and the differential output _V2 at this time is obtained. At time T ₃ , the differential output also turns on transistor Q ₂ ,
At T ₄ , a differential output swinging to the negative side is obtained. After T ₄ , there is no change in voltage V ₁ , so differential output V ₂ is zero.

Figure 5.3 shows the collector voltage of transistor _Q2 .
The voltage waveform of V ₃ is shown. Until time T ₁ , the base input of transistor Q ₂ is zero and the transistor
Q ₂ is off, therefore V ₃ is high level, at time T ₁ transistor Q ₂ is turned on, so V ₃ is low level,
Once voltage V ₁ rises and stabilizes, transistor Q ₂
is off, and at the high level time T ₂ , the differential output V ₂ becomes low level, so the transistor Q ₂
keep off. At time T ₃ , again transistor Q ₂
turns on, and the voltage _V3 becomes low level.

The timer circuit section 4 is reset when _V3 , which is the input voltage of the timer circuit section 4, is at a low level, and continues normal time counting when it is at a high level.

That is, in FIG. 5, the time count operation is reset at times _T1 and _T3 when the voltage of _V3 becomes low level, and the time count is set to zero. time
After T ₃ ′, the input voltage V ₃ of the timer circuit section is held at a high level and performs a time counting operation.

When the time counting operation of the timer circuit section 4 is completed (after the specified time has elapsed), the output voltage of the timer circuit section becomes low level (time _T5 ). This is the fifth
Shown in Figure 4.

When the output voltage V ₄ of the timer circuit section 4 is at a high level, the transistor Q ₃ is turned on, and when the relay on time reaches T ₅ and V ₄ is at a low level, the transistor Q ₃ is turned off and the relay is also turned off. is as described above.

Effects of the Invention As described above, the iron of the present invention includes a usage state detection switch section that is turned on and off by the reciprocating movement of the iron body, a differentiation circuit section that differentiates the output of this usage state detection switch section, and a differentiation circuit section that differentiates the output of this usage state detection switch section. a first switch section that is turned on and off by the output of the circuit section and outputs a signal having a predetermined pulse width and a predetermined voltage from the signal output from the differential circuit section; By comprising a timer circuit section that is reset by the output of the timer section and a second switch section that turns off the heater power supply according to the output of the timer section after a certain period of time has elapsed,
With an extremely simple circuit configuration, the power to the iron can be safely shut off, and the timer circuit can be reliably reset in response to the operation of the iron during use, preventing malfunctions during use. It is possible.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the iron of the present invention, Fig. 2 is a sectional view showing an embodiment of the usage state detection switch, Fig. 3 is an explanatory diagram of the operation of the usage state detection switch, and Fig. 4 is an illustration of the operation of the usage state detection switch. FIG. 5 is a circuit diagram of an embodiment of the present invention, FIG. 5 is a voltage waveform diagram of each part of FIG. 4, and FIG. 6 is a conventional circuit diagram. DESCRIPTION OF SYMBOLS 1... Usage state detection switch section, 2... Differential circuit section, 3... First switch section, 4... Timer circuit section, 5... Second switch section.

Claims (1)

[Claims] 1. A usage state detection switch section that is turned on and off by the reciprocating movement of the iron body, a differentiation circuit section that differentiates the output of this usage state detection switch section, and an operation state detection switch section that is turned on and off by the output of this differentiation circuit section. , a first switch section that outputs a signal having a predetermined pulse width and a predetermined voltage from the signal output from the differentiation circuit section; and a timer circuit section that is reset by the output of the first switch section. and a second switch section that turns off the heater power supply based on the output of the timer section after a predetermined period of time has elapsed.