JPS6234519A - Timer device of roaster - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a timer device for a roaster, which adjusts the set roasting time according to the temperature of the roasting chamber and also adjusts the roasting time according to the ambient temperature. Regarding adjusting baking time.

[Conventional technology]

A conventional timer device for a roaster is, for example,
As described in Publication No. 984, a time constant circuit consisting of a capacitor and a resistor is applied by turning on a switch connected between a power source and a heater, and the terminal voltage is changed to a diode by charging the capacitor of the time constant circuit. The circuit is equipped with an SCR switching element that operates when the breakover voltage exceeds a breakover voltage of A configuration is known in which a 1-no-mister whose resistance changes depending on the resistance is connected. In this configuration, when the switch is turned on during the first roasting operation, the heater is energized and the capacitor of the time constant circuit starts charging, and when the terminal voltage exceeds the diode flakeover voltage by charging the capacitor, the switching element is activated. When the relay is activated and the switch is turned off, power to the heater is cut off. When the switch is turned on again for the next roasting, the heater and time constant circuit are energized in the same manner as described above. In this case, the resistance of the thermistor has decreased due to the residual heat in the roasting chamber during the previous roasting, and the rise in the terminal voltage of the capacitor activates the relay faster than the previous time, so that roasting can be done evenly. It has become.

[Problem that the invention seeks to solve]

With the above-mentioned conventional roaster timer device, there is no problem if the ambient temperature of the roaster is constant, but since the ambient temperature where the roaster is used changes from, for example, 5℃ to 35℃, the thermistor is There is a problem in that the capacitor charging time changes depending on the ambient temperature and the roasting time changes with respect to the set time.

The present invention was made in view of the above-mentioned problems, and is a roaster that can perform uniform roasting by correcting the set roasting time according to changes in the residual heat temperature of the roasting chamber and the humidity of the outside air. This invention provides a timer device.

[Means for solving problems]

A timer device for a roaster according to the first invention includes a switch connected between a power source and a heater, a time constant circuit including a capacitor and a resistor to which voltage is applied when the switch is turned on, and a time constant circuit that is made up of a capacitor and a resistor when the switch is turned on. a switching circuit that is turned on when the capacitor of the time constant circuit is charged and turned off when the set voltage of the capacitor of the time constant circuit is charged; and a relay that holds the switch in the on state when the switching circuit is turned on and turns off the switch when the switching circuit is turned off. A temperature compensation element whose resistance changes according to the temperature change in the roasting chamber is connected to the time constant circuit as a resistance component, and a temperature compensation element whose resistance changes according to the temperature change in the roasting chamber is connected to the switching circuit. It is characterized by the provision of a temperature compensation element whose resistance changes.

Second? In the roaster timer device of the rrth invention, the switching element of the switching circuit is composed of a PUT and a transistor, and the switching element inserted in the gate of the PUT is connected in parallel with the temperature compensation element of the detection level setting circuit at room temperature. This device is characterized in that a resistance element having a resistance value greater than that of the temperature compensation element is connected.

A timer device for a roaster according to a third aspect of the present invention is characterized in that a resistance element having a resistance value greater than the resistance value of the temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the time constant circuit. .

In the fourth roaster timer device, the switching element of the switching circuit is composed of a PIJT and a 1-transistor, and the switching element inserted into the gate of this PUT is connected in parallel to the temperature compensation element of the detection level setting circuit at room temperature. A resistive element having a resistance value greater than that of the temperature compensating element at normal temperature is connected in parallel with the temperature compensating element of the time constant circuit. be.

[Effect]

In the roaster timer device of the present invention, when the switch is turned on, the heater starts to be energized and the time constant circuit is energized. By energizing this time constant circuit, the capacitor is charged according to the resistance of the resistance and the temperature compensation element. On the other hand, the switching circuit also turns on, and the relay maintains the switch on state. Then, as the roasting progresses due to energization of the heater, charging of the capacitor of the time constant circuit also progresses, and when the terminal voltage of the capacitor becomes higher than the gate side of PUT set by the detection level setting circuit of the switching circuit, the PUT conduction between the anode and cathode of
The switching circuit is turned off, the switch is turned off by the relay, electricity is cut off to the heater, and roasting is completed. The next roasting is also performed by turning on the switch, but since the temperature of the roasting chamber is already high due to the residual heat from the previous roasting, the resistance value of the temperature compensation element is also changed, and the The charging time for the capacitor in the constant circuit is shorter than last time, the switching circuit turns off faster than last time, the relay turns off the switch, and roasting ends, and roasting is done evenly compared to last time. In addition, the temperature compensation element in the level detection circuit of the switching circuit adjusts the conduction level between the anode and cathode of the PLJT according to the outside temperature, correcting variations in roasting due to ambient temperature, and ensuring uniform roasting regardless of the ambient temperature. Burned.

Further, a high-resistance resistance element connected in parallel with the temperature compensating element of the time constant circuit is used to adjust the time difference between the first roasting and the next roasting to avoid the extremely fi roasting ii. Further, a high resistance element connected in parallel with the temperature compensation element of the detection level setting circuit of the switching circuit adjusts for extreme drops in operating voltage at low temperatures.

〔Example〕

The configuration of an embodiment of the present invention will be explained with reference to FIG.

1 is an AC power source, and a heater circuit 2 is connected between both terminals of this AC power source 1. A switch 3 is connected between the AC power source 1 and the heater circuit 2, and the switch 3 has a first contact 3a and a second contact 3b connected in series. Further, the heater circuit 2 has an upper heater 4 installed at the upper part of the roasting chamber (not shown) and a lower heater 5 installed at the lower part, and a changeover switch 6 is connected to both the heaters 4 and 5. The first contact 7 of this change-over switch 6 switches between low roasting, which connects both heaters 4 and 5 in series, and top-heat roasting, which short-circuits the second heater 5.
short-circuits the Dobe heater 4 and short-circuits the lower heater 5 of the first contact 7.
Due to a short circuit, both heaters 4 and 5 are connected in parallel to switch to strong roasting.

and first and second contacts 3a of the switch 3.

A DC constant voltage power supply circuit 10 is connected to the connection point with the resistor 11.3b. Parallel connected bleeder resistor 12.13.14, conde laser 15. resistance 16
゜Series circuit of diode 17 and the bleeder resistor 12
13 and 14, and a capacitor I 18 connected in parallel to the capacitor 15. Further, in parallel with the constant voltage power supply circuit 10, there is an energization display element 22 such as a neon lamp.
is connected.

Further, 23 is a time constant circuit, which is connected between the bleeder resistor 12, 13, 14 of the constant voltage power supply circuit 10 and the power supply 15. This time constant circuit 23 includes a resistor 24.degree. and a negative characteristic thermistor 25.the resistance of this time constant circuit 23 serves as a temperature compensation element. It is composed of a series circuit of a variable resistor 26 and a capacitor 27. Further, a resistive element 28 having a resistance value greater than the resistance value of the one-dimensional resistor 25 at room temperature is connected in parallel to the two-dimensional resistor 25.

The resistance value of this thermistor 25 changes in accordance with the temperature change in the roasting chamber (it is placed in the ☆ position).

Further, an electromagnetic coil 30 of a relay 29 and an NPN transistor 32 of a switching circuit 31 are connected in parallel with the time constant circuit 23. Further, a diode 33 is connected in parallel with the electromagnetic coil 30.

Also, the electromagnetic coil 30 of the relay 29 and the transistor 3
A detection level setting circuit 34 of the switching circuit 31 is connected in parallel with the second series circuit. This detection level setting circuit 34 is connected to a negative characteristic thermistor 36 as a resistance 35.4 degree compensation element. Variable resistor 37 forming a reference voltage. li
A resistor 38 and a bias resistor 39 are connected in series. This thermistor 36 is arranged at a position where its resistance value changes in accordance with the outside temperature. Furthermore, a resistance element 40 having a resistance value greater than the resistance value of the thermistor 3G at room temperature is connected in parallel to the thermistor 36.

Further, the switching circuit 31 includes a resistor 41 and a PUT (programmable unijunction transistor) 4 connected in parallel with the capacitor 27 of the previous time constant circuit 23.
2 are connected in parallel. The anode of this PtJT 42 is connected to the anode side of the capacitor 27 of the time constant circuit 23 via the resistor 41, and the gate is connected to the connection point between the thermistor 36 and variable resistor 37 of the detection level setting circuit 34, Further, a reference voltage is applied between the gate and cathode of this PUT 42, and the base of the transistor 32 is connected to a connection point between a resistor 38 and a bias resistor 39 that form this reference voltage.

Further, a cancellation switch 'f-43 is connected between the base and emitter of the transistor 32 of the switching circuit 31, and when the cancellation switch 43 is turned on, the transistor 32 of the switching circuit 31 is turned off.
The excitation coil 30 is de-energized.

Furthermore, a timer switch 44 is connected in parallel with the switch 3, and this timer switch 44 is used for roasting for a relatively long time, and is constituted by a mechanical timer in addition to electronic timer control.

Further, contacts 3a and 3b of the switch 3 are connected to the relay 2.
When the electromagnetic coil 30 of No. 7 is energized, it is held in the on state, and when the electromagnetic coil 30 is de-energized, it is turned off.

Further, by increasing the resistance value of the variable resistor 26 of the time constant circuit 23, the charging time of the capacitor 27 is improved.

Next, referring to FIG. 2, on the front panel 46 of the roaster main body 45 there is a push button 2 for turning on the switch 3.
411 Roasting time adjustment knob 48 for adjusting the resistance value of the variable resistor 26 of the time constant circuit 23. A push button 2499 for turning on the cancel switch 43 and a display section 50 for confirming the lighting of the energization display element 22 are provided. A thermistor 25 of the time constant circuit 23 is provided, a thermistor 36 of the detection level setting circuit 34 of the switching circuit 31 is provided at the bottom, and an operation knob 53 of the heater changeover switch 6 is provided at one end surface.

Next, the operation of this embodiment will be explained.

When roasting bread etc. using an electronic timer, the switch 3 is turned on by operating the push button 41, and the contact 3 is turned on.
a and 3b are opened to energize the heater circuit 2, and the heater circuit 2 is energized in the state set by the changeover switch 8, for example, with both heaters 4 and 5 connected in series or in parallel.

Also, when the contact 3a of the switch 3 is opened, the constant voltage power supply circuit 1
0 is turned on, the time constant circuit 23 and the detection level setting circuit 34 of the switching circuit 31 are energized, and the time constant circuit 23 is connected to the fixed resistor 24 . Thermistor 25. variable resistance 26
The capacitor 27 is charged by the resistive force formed by the capacitor 21 and the closed circuit of the capacitor 21. and switching circuit 31
A constant voltage divided by the resistance divider circuit of the detection level setting circuit 34 is applied to the gate of the PUT 42, but the gate voltage is lower than the voltage across the capacitor 27 of the time constant circuit 23, and the base current of the transistor 32 flows, the Ti magnetic coil 30 of the relay 29 is energized, and the electromagnetic coil 3o
is excited, and the ON operation of the switch 3 is maintained.

When the resistance value of the variable resistor 26 is constant, the time constant circuit 23 charges the capacitor 27 according to the resistance value of the thermistor 25, and the voltage across the capacitor 27 is output to the PUT 42.
When the voltage becomes higher than the 1-voltage, conduction occurs between the anode and cathode of the PUT 42, the capacitor 27 is discharged through the resistor 41, and the base voltage of the transistor 32 decreases.
This transistor 32 becomes non-conductive, the electromagnetic coil 3o of the relay 29 becomes de-energized, and the switch 3 is turned off.
As a result, contacts 3a and 3b are opened, power supply to heater circuit 2 is interrupted, and roasting is completed. At the same time, the energization display element 22 is also turned off.

Next, when roasting is continued by turning on switch 3,
Roasting is performed as described above, and the thermistor 25 of the time constant circuit 23 is heated at the residual heat temperature from the previous roasting in the roasting chamber 51.
The resistance value of the capacitor 25 decreases, the charging time of the capacitor 25 becomes shorter than the previous time, the conduction time of the PUT 42 also becomes shorter, the switching circuit 31 turns off the relay 29 in a shorter time than the previous time, and the roasting ends.

In this way, due to residual heat in the roasting chamber 51, the resistance value of the thermistor 25 of the time constant circuit 23 is lowered, and as shown in the charging characteristic of the capacitor 27 of the time constant circuit 23 shown in FIG. ℃), the next roasting time is T2 compared to the first roasting time T1, and the next roasting time is shortened by time T3.

Further, the resistance value of the thermistor 36 inserted into the detection level setting circuit 34 of the switching circuit 31 changes with changes in ambient temperature, and the setting level of the switching circuit 31 is changed, so that the PUT 42 obtains a gate voltage according to the ambient temperature. . In other words, as shown in Fig. 2, the charging voltage characteristics of the capacitor 27 of the time constant circuit 23 change more slowly at low temperatures (5°C) than at room temperature (20°C), and at high temperatures (35°C). The characteristics change rapidly, and when the temperature is low, the first roasting time T4 and the next roasting time T5 are too long, and when the temperature is high, the first roasting time T6 and the next roasting time T7 are too long, but it is difficult to detect. By raising the detection level of the switching circuit 31 using the thermistor 42 of the level setting circuit 34 when the temperature is high and lowering the detection level when the temperature is low, substantially uniform roasting can be performed regardless of the ambient temperature.

Further, the resistance value of the negative characteristic thermistor 25 of the time constant circuit 23 changes greatly with respect to temperature changes, and the time difference between the next roasting time T2 and the first roasting time T1 is large. By connecting a resistance element 28 having a high resistance with respect to the resistance value at room temperature, it is possible to reduce the I'J difference T3 between the first roasting time T1 and the next roasting time T2.

Furthermore, as shown in FIG. 4, the temperature characteristic of the negative characteristic thermistor 36 of the detection level setting circuit 34 of the switching circuit 31 is such that the resistance value becomes extremely high at low temperatures, and the operating voltage of the PUT 42 decreases too much. Since a resistance element 40 with a high resistance value J of the thermistor 36 at room temperature is connected to the resistance element 40, the resistance characteristic a of the thermistor 36 corresponding to the resistance of the time constant circuit 23 is changed as shown in FIG.
is corrected by the resistance element 40 so that the roasting time at low temperature does not become short.

Further, the roasting time is adjusted by adjusting the variable resistor 26 of the time constant circuit 23, and also by adjusting the PUT4 of the switching circuit 31.
Adjustment of the reference voltage applied to 2 is performed by a variable resistor 37.

Further, when the roasting is interrupted in the middle of the roasting, the cancel switch 43 is turned on, and the base voltage of the transistor 32 of the switching circuit 31 decreases.
2 becomes non-conductive, the electromagnetic coil 30 of the relay 29 becomes de-energized, the switch 3 turns off, and the heater circuit 2
The energization is interrupted and the roasting ends.

In addition, when roasting for a relatively long time without electronic control, the timer switch 44 energizes the heater circuit 2 for a set time.

Further, in the embodiment described above, a negative characteristic thermistor 3G was used as the temperature compensation element of the detection level setting circuit 34 of the switching circuit 31, but a positive characteristic thermistor is used when connecting between the gate and cathode of the PUT 36 of the switching circuit 31. . Further, although a negative characteristic glue mistor 25 is used as the temperature compensation element of the time constant circuit 23, a positive characteristic thermistor may be used depending on the connection position.

(Effects of the Invention) According to the present invention, a temperature compensation element whose resistance changes according to temperature changes in the roasting chamber is connected to the time constant circuit as a resistance component, and a switching element detection level setting circuit of the switching circuit is connected to the temperature compensation element whose resistance changes according to temperature changes in the roasting chamber. Temperature 7i where resistance changes according to temperature change
! Since the i-compensation element is installed, the roasting time can be automatically adjusted from the first roasting time to the next roasting time according to the residual hot water level in the roasting chamber, and this roasting time can also be adjusted by the ambient temperature. Therefore, it is corrected according to the ambient temperature to ensure uniform roasting.

Further, according to the present invention, the switching circuit of the switching circuit is composed of a PIJT and a transistor, and this PUT
A resistance element with a resistance value greater than the resistance value of this temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the switching element detection level setting circuit inserted into the gate of the switching element. The operating voltage of the detection level setting circuit is corrected by correcting the sudden resistance change of the compensation element, and roasting can be made uniform even at low temperatures.

Furthermore, according to the present invention, a resistance element whose resistance value is greater than the resistance value of the temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the time constant circuit, so that the time difference between the first roasting time and the next roasting time is corrected. This allows for more uniform roasting.

Further, according to the present invention, the temperature characteristics of the temperature compensation element are corrected to compensate for sudden resistance changes of the temperature compensation element at low temperatures, and the operating voltage of the detection level setting circuit is corrected. By correcting the difference in roasting time, more uniform roasting can be achieved.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention. Fig. 1 is a circuit diagram of the timer design of the roaster. Fig. 2 is a perspective view of the roaster. Fig. 3 is a diagram of charging characteristics of the capacitor of the time constant circuit. , FIG. 4 is a temperature characteristic diagram of the thermistor of the switching circuit, and FIG. 5 is a correction characteristic diagram of the thermistor. 1...power supply, 4,5...heater, 23...time constant circuit,
25.36...Thermistor as a temperature compensation element, 27
... Capacitor, 28.40... Resistor, 29... Relay, 31... Switching circuit, 32... Transistor,
34...Detection novel setting circuit, 42...PU$, 3z

Claims (4)

[Claims] (1) A switch connected between the power supply and the heater, a time constant circuit consisting of a capacitor and a resistor to which voltage is applied when the switch is turned on, and a time constant circuit that is turned on when the switch is turned on, and a capacitor of the time constant circuit. A switching circuit that is turned off when charging a set voltage, and a relay that holds the switch in the on state when the switching circuit is on and turns off the switch when the switching circuit is off, and the time constant circuit has a resistance component. A temperature compensating element whose resistance changes according to the temperature change in the roasting chamber is connected as a temperature compensating element, and a temperature compensating element whose resistance changes according to the ambient temperature change is provided in the switching element detection level setting circuit of the switching circuit. A roaster timer device featuring: (2) A switch connected between the power source and the heater, a time constant circuit consisting of a capacitor and a resistor that is applied when the switch is turned on, and a capacitor in the time constant circuit that is turned on when the switch is turned on. a switching circuit that is turned off when charging a set voltage, and a relay that holds the switch in the on state when the switching circuit is on and turns off the switch when the switching circuit is off, and the time constant circuit includes a resistor. a humidity compensation element whose resistance changes according to the temperature change in the roasting chamber is connected as a minute, and a temperature compensation element whose resistance changes according to the ambient temperature change is provided in the switching element detection level setting circuit of the switching circuit; The switching element of the switching circuit is composed of a PUT and a transistor, and a resistance element whose resistance value is larger than the resistance value of the temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the switching element detection level setting circuit inserted into the gate of the PUT. A timer device for a roaster that is characterized by: (3) A switch connected between the power supply and the heater, a time constant circuit consisting of a capacitor and a resistor to which voltage is applied when the switch is turned on, and a time constant circuit that is turned on when the switch is turned on and the capacitor of the time constant circuit is turned on. A switching circuit that is turned off when charging a set voltage, and a relay that holds the switch in the on state when the switching circuit is on and turns off the switch when the switching circuit is off, and the time constant circuit has a resistance component. a temperature compensating element whose resistance changes according to the temperature change in the roasting chamber, and a temperature compensating element whose resistance changes according to the ambient temperature change is provided in the switching element detection level setting circuit of the switching circuit; A timer device for a roaster, characterized in that a resistance element whose resistance value is greater than the resistance value of the temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the time constant circuit. (4) A switch connected between the power supply and the heater, a time constant circuit consisting of a capacitor and a resistor to which voltage is applied when the switch is turned on, and a time constant circuit that is turned on when the switch is turned on and the capacitor of the time constant circuit is turned on. A switching circuit that is turned off when charging a set voltage, and a relay that holds the switch in the on state when the switching circuit is on and turns off the switch when the switching circuit is off, and the time constant circuit has a resistance component. a temperature compensating element whose resistance changes according to the temperature change in the roasting chamber, and a temperature compensating element whose resistance changes according to the ambient temperature change is provided in the switching element detection level setting circuit of the switching circuit; The switching element of the switching circuit is composed of a PUT and a transistor, and a resistance element whose resistance value is larger than the resistance value of this temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the switching element detection level setting circuit inserted into the gate of this PUT. A timer device for a roaster, characterized in that a resistance element whose resistance value is greater than the resistance value of the temperature compensation element at room temperature is connected in parallel with the temperature compensation element of the time constant circuit.