JPS58176497A - Control device for fan - Google Patents

Abstract

PURPOSE:To improve the safety of the fan by a method wherein restarting of the fan is stopped in case a signal showing approach or contact of an user or some substance having equivalent electrical and mechanical properties is sent from a blade guard continuously for a predetermined period of time or more. CONSTITUTION:The motor 14 for the fan is unabled to be restarted for the approach detecting signal continued longer than a given time and is brought into a condition waiting for a next command by a method wherein a reset circuit 12a, putting a stop mechanism 13 into an operating condition when the signal from a detecting circuit 11 is continued for a predetermined period of time or more and maintaining the motor in a stopped condition, is provided in the device. Thus, the motor will never be restarted automatically because the user has forgotten to cut the electric source therefor even in case a detecting sensibility is varied by the atmosphere of circumstance and the motor is left stopped or the motor continues the stopped condition due to a reason coming from the place of installation or some other reasons except the user.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an electric fan, and an object of the present invention is to improve safety.

Conventionally, when approaching or touching the blade guard of an electric fan, the blade motor suddenly stops, but if the blade guard continues to approach or come into contact with it, the blade motor will stop for a long time, and from the user's perspective, the fan will be turned off. It is determined that there is
There were times when I made an unexpected mistake.

The present invention solves the above-mentioned conventional drawbacks, and embodiments thereof will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a time chart showing the operation of a conventional electric fan control device. In FIG. It's gone. This shows that the blade approaches or contacts the blade guard only for a time Δt1 from the width tl. B is the time during which DC current is applied to the electric fan motor and the brake is applied.In order to apply DC current to a single-phase induction motor used in an electric fan and bring it to a sudden stop, a fairly large current must be applied, and there is no excess time. If it is too long, there is a risk of burning out the motor. Therefore, the brake application time Δt2 is set to about 1 second.

C shows the rotation state of the electric fan motor, which is stopped by applying the brake at time 3 vane time t1, and even after the brake is released at time t3, the electric fan remains stopped until time t4, and restarts at time t4. to start. The period from time t3 to t4 is a cooling period for the motor, and if the stub operation is repeated many times, the temperature of the motor will gradually rise and eventually burn out, so even if it is repeated, it will always be at time t5. Consideration has been given to providing a cooling period during ta4. The time during this period is about 3 to 5 seconds. By the way, if the proximity detection time is △
If t1 is longer than Δt3, the electric fan starts rotating after time Δt1 has elapsed, that is, at the same time as the contact detection is released. This means that the contact detection sensitivity of the electric fan has become extremely high for some reason, and the hysteresis of the detection circuit has also affected the user's approach and contact, causing the electric fan to stop abruptly. Despite this, the detection signal does not disappear and the fan remains stopped, and if the sensitivity decreases for some reason, it may restart as I remembered. Most proximity detection methods involve placing a high impedance between the blade guard and the power supply and using the signal as a minute current that flows from the power supply to the ground through the user, so it is not affected by the external environment, especially humidity. This kind of phenomenon is not uncommon.

In addition, in ordinary homes, the curtains may stop due to contact not only by the user but also by curtains, etc. If the curtains are in contact with the wind or the like and the contact is released for some reason, the curtains will start spinning again.

When it is stopped, the appearance is exactly the same as when the fan is not in use and is stopped, so I thought that the fan was stopped.
They can sometimes turn around after you go out or go to bed, causing unexpected disasters. It is said that exposure to the wind from an electric fan while sleeping is especially bad for the health of babies and the elderly.

2, E shows the proximity detection signal and the operating state of the motor in one embodiment of the present invention, and the detection signal continues from time t5 to t7.

As in Figure 1, the fan does not rotate while the detection signal continues, but when time Δt6 has passed since the detection signal first entered,
The feature is that even if the proximity signal disappears at time t7, the 1:7 signal to Mo5 continues to be stopped. This time t6
If the detection signal continues beyond , the fan will not restart even if the detection signal disappears after that. This solves all the problems mentioned above. By the way, t5
The problem is how long the time Δt6 from t6 to t6 should be. Generally, when moving an electric fan, the user approaches or touches the electric fan. Of course, the stop mechanism may also work. The electric fan's power cord is about 2 meters long, so either way you can only move it within this range. I tried many operations, such as when replacing it on a table, but it was about 10 to 1
It is possible to move to most places in 5 seconds or more.

In other words, if the detection signal remains on for 10 to 15 seconds or more, there is no problem even if the electric fan is completely reset and put into a standby state. FIG. 3 is a block diagram showing the configuration of a control device that performs these operations. 10 is a blade guard, 11 is a detection circuit that detects approach and contact with the blade guard, 12 is a determination circuit that receives a signal from the detection circuit 11 and controls the time for operating the stop mechanism 13, and 13 is a DC current. A stop mechanism 14 including a power source is a motor for rotating the blades of the electric fan. 12
& is a reset circuit that activates the stop mechanism 13 and maintains the motor in a stopped state when the signal from the detection circuit 11 continues for a predetermined time or longer, as shown in FIG. For proximity detection that continues past time t6,
This function disables the motor from restarting and puts it in a state where it is ready to wait for the next command.

As described above, according to the present invention, even if the detection sensitivity changes due to the surrounding environment and the device stops and continues to stop, or even if the device continues to stop due to a cause other than the user due to the installation location, the user can turn the power on. This feature is highly effective in terms of energy saving and safety, as there is no need to automatically restart the device if you forget to turn it off.

[Brief explanation of drawings]

FIG. 1 is a time chart showing the control operation of a conventional electric fan, FIG. 2 is a time chart showing the operation of a control device in an embodiment of the present invention, and FIG. 3 is a block diagram of the same circuit. 7 Page 10...Blade guard, 11...Detection circuit, 12...Judgment circuit, 12+a...
Reset circuit, 13...Stop machine L14...
····motor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure t, tx tJt< Figure 2

Claims (1)

[Claims] A stop mechanism that applies direct current to the motor that rotates the blades to quickly stop the rotation, a detection circuit that detects when a user approaches or touches the blade guard, and a time period for operating the stop mechanism with a detection signal from the detection circuit. A judgment circuit that determines the timing of the blade guard, and an approach from a user of the blade guard or an object with equivalent electrical and mechanical properties. < is a fan control device that includes a reset circuit that stops restarting the fan, resets all operations, and enters a standby state when a contact signal continues for a certain period of time or more.