JPH0449699Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a heating control circuit having a timer means and suitable for use in heating appliances, for example.

(B) Conventional technology Conventionally, heating appliances have had heating control circuits that operate on "high" for a predetermined time after turning on the power, regardless of the set temperature, and then operate to maintain the set temperature after a predetermined time. There are also heating control circuits that operate only during a predetermined period of time and then stop operating.The predetermined period of time is usually set to be variable so that the user can select the optimum conditions. , For example, Jikko 40-430
It is disclosed in the publication No. The device disclosed in this publication uses a timer knob to select the amount of time measured by the timer, and its configuration is usually based on the second
As shown in the figure, a selection switch 2 is switched by a timer knob 1 to select the amount of time measured by a timer 3. However, in such a configuration, for example, when the selection switch is set to the "5 hour" position, for some reason this selection switch may change.
When it is in the OPEN state, it will be in a continuous heating state,
The user could heat the product more than necessary, posing a risk of burns or the like to the user.

(c) Problems to be solved by the invention In consideration of the above-mentioned drawbacks, the present invention aims to stop the operation of the heating means after a predetermined time when the selection means malfunctions.

(d) Means for Solving Problems The heating control circuit of the present invention is configured such that when the selection means outputs a plurality of timed amount designations or the timed amount designation to the timer setting means for setting the timed amount of the timer means. A guarantee means is provided for setting a predetermined amount of time in the timer means when the timer means is not outputting.

(E) Effect Since the present invention is constructed as described above,
When the selection switch malfunctions or breaks down for some reason and the selection means outputs multiple time measurement amount specifications or no time measurement amount specification, a predetermined time measurement amount can be set in the timer means by the guarantee means. It is something.

(f) Embodiment An embodiment of the present invention will be explained based on FIG. 1.
11 is a heater (heating means) embedded in a carpet (not shown), 12 is a temperature detection means for detecting the temperature of the carpet, 13 is a temperature setting means for setting a desired temperature of the carpet, and 14 is a drive described later. When the “H” level signal is output from the RS-F・F22, the temperature detection means 1
2 and a heating control means which controls the energization to the heater 11 based on the output of the temperature setting means 13 and stops the energization to the heater 11 when an "L" level signal is output; 16 is an automatic reset type switch for starting and stopping heating; 17 is a T-F-F with the switch 16 connected to the C terminal; it operates at the rising edge of the input signal; The output signal of the OR gate 21E of the timer setting means 21, which will be described later, is input from the R terminal via the OR gate 18, and is set to "L" in the reset state.
It is designed to output a level signal.

19 is a timer means for measuring a predetermined time;
Its configuration will be detailed below. 19A is an oscillator,
For example, a commercial power supply frequency is full-wave rectified to obtain 100Hz or 120Hz. (Here, it is assumed to be 120Hz.) 19B inputs the output signal of the T-F・F 17 to the S terminal, and inputs the output signal of the above-mentioned initial circuit 1 to the R terminal.
For oscillator switching, the output signal of 5, the inverted output signal of T-F・F17, and the output signal of OR gate 21E, which will be described later, are input via OR gate 19C.
This is an RS-FF, which operates on the rising edge of the signal. 19D is the oscillator 19A and RS-
The AND gate 19E inputs the output signal of F/F19B from the C terminal to the AND gate 19D.
Input the output signal of T-F・F from the R terminal.
This is a frequency divider circuit that inputs the output signal of 17, divides the frequency by 120, and outputs a 1 second pulse. 19F
is a counter that inputs the output signal of the frequency dividing circuit 19E from the C terminal and the output signal of the T-F・F ₁₇ from the R terminal, and counts the output pulses of the frequency dividing circuit 19E. An "H" level signal is output from the _O2 terminal after 3 hours from the terminal, and an "H" level signal from the _O3 terminal after 5 hours.

20 is a selection means for specifying the amount of time measured by the timer means 19 to a timer setting means 21, which will be described later, and has a movable contact (a) and four fixed contacts (b), (c), (d), and (e). It consists of a selection switch 20A, and an adjustment knob 20B mechanically connected to the movable contact (a). The four fixed contacts (b), (c), (d), and (e) are "continuous" (the timer means 19 clocks infinity), "5 hours", and "3 hours" in that order. , is a contact point for specifying "1 hour".

Reference numeral 21 denotes a timer setting means for setting a time measurement amount in the timer means 19 based on the output signal of the selection means 20, which will be described in detail below. 21A is the _O3 terminal of the counter 19F and the 5 of the selection switch 20A.
21B is an AND gate that inputs the output signal of the time fixed contact (c), 21B is an AND gate that inputs the output signal of the O ₂ terminal of the counter 19F and the 3-hour fixed contact (d) of the selection switch 20A, and 21C is the counter 1
The output signal of the O ₁ terminal of 9F is inputted from one input terminal, and the output signal of the 1-hour fixed contact (E) and the guarantee means 21F, which will be described later, is inputted via the OR gate 21D. The OR gate 21F inputs the output signals of the gates 21A, 21B, and 21C, when the selection means 20 specifies a plurality of time measurement amounts or when no time measurement amount is specified, sets the time measurement amount of one hour to the timer means 19. It is a means of ensuring that This guaranteeing means 21F has an AND gate 21F-1 which inputs the output signals of the 5-hour fixed contact (c) and the 3-hour fixed contact (d) of the changeover switch 20A, and the output signal of the continuous fixed contact (b). AND gate that inputs from one input terminal and inputs the output signals of fixed contacts (c), (d), and (e) for 5 hours, 3 hours, and 1 hour from the other input terminal via OR gate 21F-2 Input the output signals of 21F-3 and the 1-hour fixed contact (E) from one input terminal, and
AND gate 21F-5 which inputs the output signals of fixed contacts (C) and (D) for time and 3 hours from the other input terminal via OR gate 21F-4, and the respective fixed contacts (B) and (C). , (d) and (e), and the AND gates 21
OR gate 21 inputting the output signals of F-1, 21F-3, 21F-5 and NOR gate 21F-6
It consists of F-7.

23 inputs the output signal of the T-F・F 17 from the S terminal, and inputs the output signal from the initial circuit 15 from the R terminal.
, the output signal of the OR gate 21E of the timer setting means 21, and the inverted T-F.F1.
The driving RS-FF receives the output signal of No. 7 via the OR gate 23, operates at the rising edge of the signal, and outputs the signal to the heating control means 14 as described above.

The operation in the above configuration will be explained. When you first turn on the power, T-F/F17 and each RS-
F・F19B, 22 are reset, and the oscillator 19
The output signal of A is not given to the frequency dividing circuit 19E, and is not provided to the heating control means 14 for driving RS-F.F22.
Since the "L" level signal is applied, the heating control means 14 maintains the state in which power supply to the heater 11 is stopped. Here, for example, the selection switch 20
When the movable contact (A) of A is connected to the continuous fixed contact (B) and the switch 16 is turned on, T-F/F17 outputs an "H" level signal, so each RS-
The F/Fs 19B and 22 are set and output an "H" level signal, and the frequency divider circuit 19E and counter 19F are reset. Therefore, the heating control means 14 starts controlling the energization of the heater 11 based on the output signals of the temperature detection means 12 and the temperature setting means 13. Also, the output of the oscillator 19A is transmitted to the frequency dividing circuit 1.
9E, the counter 19F performs a counting operation, but since an "L" level signal is given to one input terminal of each of the AND gates 21A, 21B, and 21C of the timer setting means 21, the counter 19F performs a counting operation. The output signal of is ignored for driving
RS-F.F22 will maintain the set state. Now, if you turn on switch 16 again,
The T-F.F17 outputs an "L" level signal, the respective RS-F.F19B and 22 are reset, and the output signal of the oscillator 19A is sent to the frequency dividing circuit 1.
9E and the heating control means 14
energization to the heater 11 is stopped.

Next, connect the movable contact (A) of the selection switch 20A to the one-hour fixed contact (E), for example, and turn the switch 16 on.
When turned ON, the same process as above is followed, but
When one hour elapses after the switch 16 is turned on, an "H" level signal is output from the _O1 terminal of the counter 19F, so the AND gate 21C outputs an "H" level signal, and T-F/F17 and each
RS-F・F19B, 22 will be reset, and the output signal of the oscillator 19A will be sent to the frequency dividing circuit 19.
E is no longer applied, and the heating control means 14 stops supplying electricity to the heater 11.

Therefore, when the movable contact (a) of the selection switch 20A is connected to the 5-hour fixed contact (c), for example, if the switch becomes open due to poor contact, etc.
When turned ON, the same process as above is followed, but
Noah gate 21F-6 of safeguard 21F is “H”
A level signal is being output, and switch 16 is turned on.
When an "H" level signal is output from the _O1 terminal of the counter 19F after one hour has passed, the T-F.
F17 and the respective RS-F/F19B and 22 will be reset, and the output signal of the oscillator 19A will no longer be given to the frequency dividing circuit 19E, and the heating control means 14 will stop supplying electricity to the heater 11. .

Also, when the movable contact (a) of the selection switch 16 is connected to the continuous fixed contact (b), for example, if the continuous fixed contact (b) and the 5-hour fixed contact (c) are fired for some reason, When switch 16 is turned on,
Since the AND gate 21F-3 of the guarantee means 21F outputs an "H" level signal, the heater 1 is turned on one hour after turning on the switch 16 as described above.
1 will be stopped. Therefore, if any of the fixed contacts connected to the movable contact (A) is shot, any of the AND gates 21F-1, 21F-3, and 21F-5 of the safeguard 21F will be set to "H" level. The signal will be output, and the heater 11 will be turned on one hour after the switch 16 is turned on.
This will result in the power being cut off.

Incidentally, if an LED or the like is connected to the output terminal of the OR gate 21F-7 of the guarantee means 21F via a driver circuit, it is possible to detect an abnormality in the selection switch 20A.

(g) Effects of the invention Since the invention is constructed as described above,
When the selection switch malfunctions or breaks down for some reason and the selection means outputs multiple time measurement amount designations or no time measurement amount designation, a predetermined time measurement amount can be set in the timer means by the security means. , the operation of the heating means can be stopped after a predetermined period of time. Therefore, there is no risk of burns or the like to the user, and the failure of the selection switch does not make it completely unusable, but it can be used for at least a predetermined period of time until it is repaired.

[Brief explanation of the drawing]

Figure 1 is an electrical circuit diagram of the heating control circuit of the present invention.
FIG. 2 is an electrical circuit diagram showing a method of selecting a timer in a conventional heating control circuit. 11... Heating means (heater), 14... Heating control means, 19... Timer means, 20... Selection means, 21... Timer setting means, 21F... Security means.

Claims (1)

[Scope of utility model registration request] A heating means for heating an object to be heated, a timer means for measuring a plurality of predetermined times, a timer setting means for setting the amount of time measured by the timer means, and a selection switch for specifying a desired amount of time for the timer setting means. and heating control means for controlling the heating means based on the output of the timer means, wherein the timer setting means is configured such that the selection means outputs designations of a plurality of timed amounts. 1. A heating control circuit comprising: a guarantee means for setting a predetermined time measurement amount in the timer means when the specified time measurement amount is output.