JPS6097719A - Timer circuit - Google Patents

Abstract

PURPOSE:To obtain a timer circuit for calcination by switching a charge start switch of a capacitor constituting a time constant circuit depending on the temperature change so as to obtain accurately the operating time required for an object to be controlled. CONSTITUTION:A relay 81 is energized at application of power and switches 13, 14 are turned on, then upper and lower heaters 8, 9 are energized, calcination is started and an auxiliary heater 16 heats a normally closed switch 45 comprising a bimetal. When temperature rises up to a prescribed temperature by the auxiliary heater 16 and the normally closed switch 45 is turned off, a capacitor 44 starts charging via resistors 42, 43 and when the charging voltage exceeds a prescribed, an FET62 is turned on, a transistor (TR)63 is turned off, a TR62 is turned off finally, the switches 13, 14 being contacts of the relay 81 are opened and power application to the heater is stopped. The time until the switch 45 is turned off is decreased by remaining heat for the next calcination, and the calcination time is decreased as a whole even if the time constant of the time constant circuit is constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a timer circuit, and particularly to one used in a roasting apparatus.

[Technical background of the invention and its problems]

When continuously cooking in a roasting device, the so-called interval t< JL, time force tkE from the first roasting to the next roasting
Since the residual heat from the first roasting affects the next roasting, the degree of roasting differs between the first roasting and the second roasting.

Therefore, in order to shorten the roasting time from the first roasting time to the second roasting time and make the roasting condition uniform, conventionally, a time constant circuit determined by a capacitor and a resistor is provided so that the capacitor pressure reaches the set voltage. In a timer circuit that releases the power supply when the capacitor reaches the set voltage and releases the power supply, a constant voltage element is installed in the discharge path that discharges the charge of the voltage capacitor at the same time, and prevents the capacitor from completely discharging and closes the terminal Some models shorten the roasting time by keeping the voltage at a constant value and starting charging from this predetermined value from the second time onwards.Also, if two capacitors are installed, when the set voltage is reached, one is completely discharged and the other is charged. There is a method that shortens the roasting time by maintaining the terminal voltage of the capacitor at a predetermined value without discharging the capacitor, and starting charging from this predetermined value from the second time onwards.

However, with such a device, it is not always possible to accurately control the roasting time from the second time onwards because the temperature in the roasting chamber of the roasting device is taken into consideration.

It's not easy.

[Purpose of the invention]

The present invention has been made in view of the above points, and provides a timer circuit that detects the temperature of a controlled object using a timer and allows the operating time of the timer to be freely varied to accurately obtain the required operating time. The purpose is to

[Summary of the Invention] The timer circuit of the present invention has a time constant circuit determined by a capacitor and a resistor ht, and when the terminal voltage of the capacitor reaches a set voltage, the timer circuit releases the power supply. A switch is provided to open and close the capacitor to regulate when charging starts, and the timer operation time is made variable. By changing the start time of charging the capacitor earlier or later, the time when Marugame is completed can be changed, thereby making the overall timer operating time variable.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the spear 10 and Figures 2 and 2.

In Figure 1, (11 is the roasting device 6)
11 has a roasting chamber inside and a door that can be opened and closed (
2) on the front, and a heater power switching knob (3) on the front of the roasting device (1) on one side of this door + 21. -I inner knob (61) and timer circuit operation knob (71)
is the provision.

An upper heater (8) and a lower heater (9) are provided above and below the roasting chamber, respectively.

, Figure 172 is the electrical circuit of the roasting device 11). switch (tsu and power switch +131
(The above upper heater (8) via a parallel circuit with 141,
Lower heater (91 and heater power selector switch U51
is connected to the auxiliary heater (161), and the timer switch (121 is formed mechanically), and the timer time setting knob (4) is connected to the timer switch (121).
Closed during the time set in . In addition, the above power switch
31 (111) kt above timer circuit operation knob (7)
Press down to open the heater power selector switch α9.Furthermore, the heater power selector switch α9 is set to the heater power selector knob (3).
The contact point (0) (town is ψ) is changed by operation. Also,
The auxiliary heater 061 is the upper and lower heaters t81.
It is designed to generate heat in proportion to +91 ftK of heat generation.

An electronic timer circuit section is formed between the power switch (131 (14)) and one end of the AC power supply IL11, and this multiple timer circuit section consists of a DC constant voltage power supply, a time constant circuit, and an output circuit. It is equipped with

The above DC constant voltage power supply has a resistor of 1211, a parallel bleeder resistor C131b: 41t2"i, and a continuum of 4tQ (I
lQn is formed by 2!1 and a diode c3α in a tie. Note that a series circuit consisting of a light emitting diode L'311 and a resistor G3 is connected between the (@ end and the @ end of this DC constant voltage power supply), and this light emitting diode BlI is placed inside the lamp cover (5). Position it and display the trace.

The time constant circuit is connected between the (-1-1 terminal and the (→ terminal) of the DC constant voltage power supply, and is connected through a diode +411 to a resistor (c), a regulator, and a capacitor.
are connected in series, and a switch (451) formed by a discharge path and a heat sensitive element is connected to this capacitor.
are each connected in parallel at ℃. The volume f4:ll is adjusted by the volume knob 16) to set a time constant. Further, the discharge path has a resistor 161 (
471° NPN type transistor (49, PNP type transistor +491 and a capacitor made of gloss).Furthermore, the above switch (451 is made of bimetal), and the above auxiliary heater ue is installed nearby and closes when the temperature is low. This auxiliary heater (Ie) is designed to open when heated.

The above output circuit consists of the above volume sir and capacitor t441.
When the power is turned on, the N-channel junction type FET (li21) is connected to the connection point with the resistor ill through the resistor ill and is turned on by the charging pressure of the capacitor port 4). Above FET fli21
The main components are NPN type transistors t631 and I41, which are turned off by the on operation of , and PNP type tosi transistors. And top%5 F B T l
The train of 121 is connected to the base of the NPN transistor Ili, ]i via the resistor 6Q (connected to the terminal and also to the resistor 17) (via the resistor 6υ), and is connected to the base of the NPN transistor Ili, ]i via the resistor (1 C (→ It is connected to the sentry, and also ";
Note FET (The source of Ii21 is connected to (
→ It is connected to the end and also connected to the emitter of the NPN type transistor. In addition, the collector of the NPN type transistor is connected to t+l II through the resistor σD.
℃ is connected to I, and the above P is connected via resistor +73.
It is connected to the base of the NP type transistor 6. Furthermore, the PNP type transistor transmitter is connected to the (→ end), and the collector is connected to the base of the NPN type transistor (64; via the resistor (13);
Furthermore, it is connected to the (→ end) via a bias resistor 5a.

The collector of the PNP type transistor 4 of this output circuit is connected to the (-1-1 terminal) through a parallel circuit of an electromagnet (811 and a diode), and the above-mentioned discharge is connected through a resistor. A PNP transistor (connected to the base of 481, forming a
The emitter of the PNP transistor 09 is connected to the (@ terminal).

In addition, when the electromagnet υ is excited, it is connected to the power switch (130) via mechanical means (not shown).
41 in a closed state.

Next, the operation of this embodiment will be explained.

When using the timer circuit, first press down on the timer circuit operation knob (71) and turn on the power switch t131 (141
is closed and the upper heater (
8) and the lower heater (9) are energized to start roasting at point 0 in FIG. 115. At the same time, the light emitting diode (311) lights up to indicate energization, and the auxiliary heater (16) turns on the bimetallic switch (
Heat all four. However, at this point, the switch (49) remains closed because the temperature is still low.

In addition, when the power switch (131) is closed, the DC constant voltage circuit produces an output, causing current to flow through the time constant circuit and the output circuit.Here, the capacitor (44) of the time constant circuit
) is connected in parallel with the switch (451), which is the auxiliary heater (1
Although the capacitor G14) is heated by the capacitor G14), it remains closed until it reaches a predetermined temperature, so that charging of the capacitor G14) is not started and the terminal voltage of the capacitor G14) is maintained at approximately Ov. Therefore, FET6z of the output circuit is in an off state, and conversely, each transistor l131 t641
e51 is turned on, the electromagnet (8υ) is energized, the power switch σ31 (141) is kept closed, and roasting continues.

When the switch (C) is heated to a predetermined temperature by the auxiliary heater 11e that heats in proportion to the temperature rise by the upper heater (8) and the lower heater (9)K, the switch (451) is opened at will. Since the state is reached, charging of the capacitor (44) is started.

In this state, when the time set in advance with the volume knob 16) has passed and the terminal voltage of the capacitor U41 reaches a predetermined value, the FET 13 turns on and the KNPN transistor IJl turns off, and at the same time, the
The NP type transistor (; 9 and the NPN type transistor become OFF state. Therefore, the excitation of the electromagnet rs11 is released at point C, and the power switch (131 (141) is opened to finish the roasting. At the moment when the transistor changes from the on state to the off state, the voltage between the collector and emitter of this NPN transistor H changes from "L" to rHJ Kf, which enters the base of the NPN transistor □a forming a discharge path, and this NPN type transistor oa is turned on, which further turns the PNP
The type transistor (49) is also turned on, and the charge in the capacitor (441) is instantly discharged from the discharge path.

If we look at the graph of the figure that contradicts the above static condition, we can see that the roasting time (T, J
! The time is the sum of the time for which the switch 14j is closed (T2) and the time for charging the capacitor (441) (T1).

Next, subsequent to the first roasting, the second and subsequent roastings are performed in the same manner as before with a certain interval time (T4). In this case, residual heat from the first roasting remains, so the time (T5) from point d where roasting starts to the point where the switch (451) formed of bimetal as a heat-sensitive element is heated to a predetermined temperature and opened is The charging time for the capacitor (441) is shorter than the first time (T6), so the charging time for the capacitor (441) is earlier than the first time (T6), but the overall charging time (T6) is the same as the first time (T3). The roasting time (T7) is short (T7).In this way, the roasting time from the second time onwards depends on the length of the time (T5) until the switch (451 reaches the predetermined temperature and is opened), that is, the temperature of the capacitor 141. It is determined by how late or early the charging starts, and the time (T,) until the switch (451 reaches a predetermined temperature and is opened) depends on the amount of residual heat in the roasting chamber. Furthermore, since this remaining P days depends on the length of the interval time (T4), the roasting time (T, ) from the second time onward will be adjusted according to the 4-digit one-pal time (T4). It is possible to make the degree of baking even after the second time.

In this adjustment, the temperature rise in the roasting chamber is indirectly sensed via the auxiliary heater tte, so that the roasting time can be adjusted accurately.

Next, another embodiment will be described based on the circuit diagram shown in Figure A-11. Note that the same parts as in the previous embodiment are given the same reference numerals, and the explanation will be omitted.

In this embodiment, a switch (191) made of bimetal as a heat-sensitive element is connected in series to the photoelectric path of a capacitor (incorporated) forming a time-determined 12 circuit, and an auxiliary heater (161) from the heater circuit is connected in series. The switch OD is disposed near the switch !υ, and the switch OD is opened when the temperature is low, and is closed when heated by the auxiliary heater tte.

Then, when the power switch f131Q41 is turned on, each heater f81 +91 K is energized to start roasting, and the auxiliary heater 1161 heats the switch 0υ in proportion to the heating by the heater 181191. However, at this point, the switch (9υ) remains open due to the low temperature, so the charging path to the capacitor 141 is opened, and charging to the capacitor (441) does not start and the terminal voltage of the capacitor (2) decreases. is maintained at approximately Ov.Therefore, as in the previous embodiment, 1'Cff1 is maintained by the electromagnets υ.
The source switch α3 (141) is maintained in the closed state to continue roasting.

When the switch eυ is heated and reaches a predetermined temperature, it becomes open, the charging path to the capacitor 9a is closed and charging starts, and when the terminal voltage of the capacitor 144 reaches a predetermined level, the FET 13 turns on and at the same time other Transistor tli3) [+41 (+51 is turned off, the excitation of the electromagnet is released, and the power switch (
13 (141) is opened, and the capacitor (44) is discharged to complete the roasting.

And after the second time I! ! As in the previous example, in the case of i-baking, the amount of residual heat corresponding to the interval time causes the time it takes for switch C It will become shorter and the degree of baking will be uniform with the first time.

In addition, in this embodiment, since no current is passed for a certain number of time constants until the start of charging the capacitor (4υ), power consumption can be saved compared to the previous embodiment.

Each of the switches (C) 0υ described above is formed of bimetal, but may be formed using other heat-sensitive elements to open and close in response to temperature changes.

In addition, each of the above switches (c) ωυ is connected to an auxiliary heater (
161 to indirectly sense the roasting temperature, it is also possible to directly sense the roasting temperature without providing such an auxiliary heater ubl.

〔Effect of the invention〕

According to the present invention, since a switch is provided that opens and closes in response to changes in the temperature of the controlled object and regulates when to start charging the capacitor of the time constant circuit, the overall timer operation time depends on the temperature of the controlled object. It can be made variable depending on the situation, and the required operating time can be obtained accurately.

Furthermore, since it can be formed by simply adding a switch that opens and closes in response to temperature changes, the structure can be simple and inexpensive.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a roasting device using an embodiment of the timer circuit of the present invention, Fig. 2 is a circuit diagram showing the electric circuit of the roasting device, and Fig. 2) shows the roasting time and capacitor terminal voltage. Graphs and diagrams showing the relationship between the two are circuit diagrams showing other embodiments. (Company)...Resistor, (4:9...Resistance and °C volume, 04)...Capacitor, +451 (9υ...Switch.

Claims (1)

[Claims] (1) In a timer circuit that has a time constant circuit determined by a capacitor and a resistor and releases the power supply when the terminal voltage of the capacitor reaches a set voltage, the timer circuit opens and closes in response to temperature changes to determine when to start charging the capacitor. A timer circuit characterized by having a regulating switch. 12) The timer circuit according to claim t-1, wherein the switch is formed of a heat-sensitive element that opens and closes in response to temperature changes, and is provided in parallel with the capacitor. Claims 1-
The timer circuit described in Section 1. 14) The timer circuit according to claim 2 or the opposite claim, characterized in that an auxiliary heater is provided near the switch to heat the object in proportion to the temperature of the object controlled by the timer.