JPS58121995A - Control apparatus of dryer - 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 The present invention relates to a dryer control device that can function more conveniently by accurately detecting the dry state.

Conventionally, in dryers, a method has been adopted in which a pair of electrodes is provided in a drying drum that accommodates objects to be dried to detect the drying state, and completion of drying is determined based on a change in resistance between the electrodes. However, in this case, there are disadvantages such as being affected by the magnetic field from the commercial power source, and malfunctioning due to the influence of static electricity generated by the friction of clothes as drying progresses. The purpose is to save power and prevent malfunctions of dryers by improving the accuracy of dryness detection.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the basic configuration of the present invention. Reference numeral 101 indicates a pair of electrodes provided in the drying drum. When an undried material comes into contact with the drying material, the resistance between the electrodes becomes small and the dry material becomes dry. When a dry object comes into contact with it, its resistance value increases. 102
is a determination circuit that detects a change in resistance of the electrode 101, and for example, a reference voltage for comparison and determination and a determination circuit that detects a change in the resistance of the electrode 101.
It consists of a comparator that takes as input. Judgment circuit 10
The output of No. 2 is input to the first time limit circuit 103 and then to the second time limit circuit 104. These timed circuits 103
, 104 is composed of a CR timer including, for example, a capacitor, a resistor, and a comparator, and the drying is completed only when a signal indicating a dry state is detected for a certain period of time. Therefore, the influence of static electricity, commercial power supply, etc. can be prevented. Reference numeral 105 is a load section connected to the second time limit circuit 104, which displays, for example, the completion of drying or stops the dryer.

FIG. 2 shows a specific electrical circuit in one embodiment,
201 is a commercial power source, which is connected to the transformer 202. The secondary output of the transformer 202 is connected to the rectifier diode 2
03 and undergoes full-wave rectification.

Then, the output is smoothed by an electrolytic capacitor 204. The smoothed output is made into a constant voltage by a resistor 205 and a constant voltage diode 206. This output becomes the power source for the circuit described below.

Reference numeral 101 represents a pair of electrodes as described above, and the resistance therebetween changes depending on the degree of dryness of the material to be dried.

The electrode 101 has a resistor 2o7. Constant voltage diode 1
208 is connected, and the constant voltage diode 208
The voltage at both ends becomes determined by the rating of the constant voltage diode 208 when the drying object has been dried to a certain level or more. This voltage is input to comparator 209. The comparator 209 has a reference voltage that is used as a reference for its judgment, and the resistor 210
, 211 and input. At this time, this reference voltage is set lower than the rated voltage of the voltage regulator diode 208.

Therefore, the output of the comparator 209 is LOW when the object to be dried is wet and the resistance value of the electrode 101 is low, and HIGH when the drying progresses beyond a certain level and the output of the constant voltage diode 208 becomes lower than the reference voltage. h.

The output of this comparator 209 is connected via a resistor 212 to a resistor 213 . It is input to a circuit made up of a capacitor 214. At this time, the resistor 212 is set to a sufficiently lower value than the resistor 213. When the output of the comparator 209 is High, a resistor 213 is connected to the capacitor 214.
Charging is done via Further, when the output of the comparator 209 is LOW, discharge occurs via the resistor 212.

The voltage across capacitor 214 is input to comparator 215 . Comparator 21sKif, father, resistor 2
The voltage divided by 16 and 217 is input as the reference voltage.

Now, when the voltage across the capacitor 2140 is charged higher than the reference voltage, the output of the comparator 216 is inverted and becomes High. Furthermore, even if the comparator 209 is temporarily reversed due to the influence of static electricity or commercial power, the output of the comparator 209 will return to LOW by the time the comparator 215 reverses. Capacitor 21 via 212
Since the charge of 4 is discharged, there is no change in the output of the comparator 216. In other words, it continues to show an undried state. Therefore, malfunctions due to temporary resistance changes between the electrodes 101 or the influence of commercial power can be prevented. Furthermore, it is also possible to prevent malfunctions due to partial drying of the object to be dried.

The output of comparator 215 is connected to capacitor 219 via resistor 218. The capacitor 219 has a resistor 2
20 is also connected. The output of the comparator 215 determines whether the capacitor 219 is discharged via the resistor 218 or charged to the capacitor 219 via the resistor 220. That is, it is charged in a dry state, and discharged in an undried state. The voltage across the capacitor 219 is input to a comparator 221 together with a reference voltage divided by resistors 222 and 223.

Now that the drying condition has stabilized, the output of the comparator 215 is Hi.
When the capacitor 219 is charged through the resistor 220 and exceeds the reference voltage, the output of the comparator 221 is inverted for the first time and becomes LOW, and the light emitting diode 225 of the load section 105 indicates the completion of drying. do.

In the above embodiment, a CR timer is used as the timer, but any timer may be used as long as it is a timer.

In addition, it goes without saying that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope of the invention.

As described above, according to the present invention, the dry state can be detected accurately and inexpensively without being affected by external influences. Furthermore, malfunctions due to partial drying of the object to be dried can be eliminated.

Therefore, it is possible to provide an extremely useful dryer that can prevent undrying or overdrying and also saves electricity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the present invention, and FIG. 2 is a specific electrical circuit diagram of one embodiment thereof. 101... Electrode, 102... Judgment circuit, 103... First time limit circuit, 104... Second time limit circuit.

Claims (1)

[Claims] an electrode disposed within the drying drum; a determination circuit that detects a change in resistance between the electrodes; a first timer circuit connected to the determination circuit and reset by the output of the determination circuit; A dryer comprising a second timer circuit connected to the output side of the circuit and set and reset by the output of the first timer circuit, and the end of drying is detected by the output of the second timer circuit. control device.