JPH0556044B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a switch circuit for ventilation fans used in bathrooms and toilets.

[Background technology] Traditionally, the light switch and the ventilation fan load switch for bathrooms and toilets were placed separately, and the user operated the switch each time. I was worried that I might forget to turn it off again. Also, conventionally,
Some bathroom ventilation switches have used current transformers, but the problem with using current transformers is that they are expensive.

Furthermore, as a switch for this kind of delay,
There are devices that use a mainspring or an oil dart pot as a delay element. However, this type of device is greatly affected by the surrounding environment such as temperature and magnetism, and cannot be delayed in operation after the switch is turned off. In addition, in the case of a spring type, a setting operation of winding the mainspring is required, and there is a problem that an oil dash pot cannot provide a long delay time. There was also a device that used an oil dart pot, and when the switch was turned on, the lighting load and the ventilation fan load started operating at the same time, and when the switch was turned off, only the ventilation fan load was turned off after a delay. However, in such a case, there are problems such as the cold in winter and the noise of the ventilation fan being loaded during use.

[Object of the Invention] The present invention has been provided in view of the above-mentioned points.
When turned off, the ventilation fan load operates for a certain period of time and then automatically stops the ventilation fan load.It also prevents forgetting to turn on or turn off the ventilation fan load, and is a two-terminal ventilation fan that can be easily installed in existing equipment. The purpose of this invention is to provide a switch circuit for

[Disclosure of the Invention] Examples of the present invention will be described below with reference to the drawings.
Figure 2 shows a block diagram, and Figure 1 shows a specific circuit diagram.
A series circuit of lighting load 1 and switch SW is connected to . By switching the switch SW to the on side terminal, lighting load 1 is turned on, and the switch
The lighting load 1 is turned off by switching the SW to the off-side terminal. A ventilation fan load 4 is operated after the lighting load 1 is turned off, and the lighting load 1 and the ventilation fan load 4 are installed in a bathroom, a toilet, or the like. 3 is a timer circuit, which includes timer IC 2, capacitors C ₄ , C ₅ , and resistor R ₄
It is composed of etc. This timer circuit 3 creates a certain delay time (time for operating the ventilation fan load 4) after the switch SW is turned off. Note that capacitor C ₄ is for smoothing, and resistor R ₄ ,
Capacitor _C5 is for time constant and determines the oscillation frequency of timer IC2. 5 is a power control circuit connected in series with the ventilation fan load 4;
TRAC, diode bridge DB, capacitor
It consists of C ₁ , resistor R _{1 ,} etc. capacitor
C ₁ and resistor R ₁ are for noise prevention, NL is a neo lamp for position display, and ZNR is a surge absorber. A switching circuit 6 controls the power control circuit 5 using a signal from the timer circuit 3, and is composed of a thyristor SCR, transistors Tr ₁ and Tr ₂ , a Zener diode ZD, a resistor R ₂ , capacitors C ₂ and C ₃ , etc. . Capacitors C ₂ and C ₃ are for noise prevention. Further, the ground lines of each circuit 3, 5, and 6 are connected to an alternating current power supply AC via an off terminal of a switch SW.

Next, the operation will be briefly explained using the block diagram of FIG. First, in order to turn on the lighting load 1, when the switch SW is turned from off to on, the lighting load 1 is turned on. At this time, the potential at point P in the figure becomes zero, and the power supply V _DD supplied to the timer circuit 3 through the resistor R ₃ becomes zero. Next, when the switch SW is turned from on to off in order to turn off the lighting load 1, the power supply V _DD is supplied to the timer circuit 3 through P→R ₃ →V. Then, the timer circuit 3 starts a delay operation after the reset state and sends a signal to the switching circuit 6. Therefore, the switching circuit 6 is turned on, turns on the power control circuit 5, and the ventilation fan load 4 starts operating. At the same time, P →
Power was supplied along the route R ₃ →V, but P→
Change the route to S→L→V. In this way, the small amount of voltage remaining across the power control circuit 5 is now directly transmitted to the timer circuit 3. After a certain delay time, the timer circuit 3
stops the signal to the switching circuit 6, and turns off the switching circuit 6 and the power control circuit 5. Then, the power supply V _DD is again supplied to the timer circuit 3 via P→R ₃ →V.

Incidentally, a block diagram of the timer IC 2 used in the timer circuit 3 is shown in FIG. The output of the oscillation circuit 7 is counted by the counter circuit 8, and the output of the counter circuit 8 is input to the output circuit 9.
The output circuit 9 outputs an H level output while the counter circuit 8 is counting the oscillation output of the oscillation circuit 7. Here, OS1, OS2, and OS3 are terminals that connect a resistor and a capacitor that determine the oscillation frequency. The oscillation frequency is determined by the resistance R ₄ shown in Figure 1,
Determined by capacitor _C5 . A reset circuit 10 stops the oscillation circuit 7 and clears the counter circuit 8 by inputting a reset signal. For the delay operation time of the timer circuit 3, the number of pulses counted by the counter circuit 8 is set in advance, and when the set number of pulses is counted, an L level signal is output from the output terminal OUT of the timer IC2. Therefore, the delay time of the timer circuit 3 is determined by the resistance R ₄ and the capacitor connected to the oscillation circuit 7.
This can be adjusted using _C5 . Note that for timer ICs that do not have an auto-reset circuit that resets when the power is turned on, a reset signal is input to the reset input pin when the power is turned on.

When the power is turned on to the timer IC2 as shown in FIG. 4b, the timer IC2 is reset and the oscillation circuit 7 outputs a pulse as shown in FIG. 4a, and the output terminal OUT outputs a pulse. 4
An H level signal is output as shown in Figure c. When a predetermined number of pulses are counted, the oscillation operation of the oscillation circuit 7 is stopped, the counter circuit 8 is cleared, and an L level signal is output from the output terminal OUT via the output circuit 9.

Next, the operation of the circuit shown in FIG. 1 will be explained.
Now, in order to turn on the lighting load 1, when the switch SW is turned on from off, the lighting load 1 is turned on. At this time, the power supply voltage _VDD supplied to the timer IC2 through the resistor _R3 becomes zero. Next, when the switch SW is turned from on to off in order to turn off the lighting load 1, power is supplied through the resistor _R3 , and the timer IC2 enters a delay operation after being in the reset state. In other words, since the timer IC2 outputs an H level signal from the output terminal OUT during the delay operation,
This signal causes the base current of the transistor Tr ₂ to flow, turning on the transistor Tr ₂ . When the transistor Tr ₂ turns on, the transistor Tr ₁ also turns on, triggering the thyristor SCR via the Zener diode ZD and the resistor R ₂ . When the thyristor SCR becomes triggered, the thyristor SCR becomes conductive and therefore the try-on
TRAC is also triggered and becomes conductive, power is supplied to the ventilation fan load 4 from the AC power source AC, and the ventilation fan load 4 is driven. At this time, only a low voltage v is generated across the conductive thyristor SCR, as shown in FIG. In this state, power cannot be supplied to the timer IC2 through the resistor _R3 , so the voltage across the thyristor SCR is directly transmitted to the timer IC2 by utilizing the conduction of the transistor _Tr1 . Then, after a certain delay time, the timer
IC2 outputs an L level signal and turns into a transistor.
Turn off Tr ₂ and Tr ₁ . Then, at the next AC zero cross point, the thyristor SCR and the triax TRAC are turned off, and the ventilation fan load 4 is turned off. In other words, the ventilation fan load 4 operates for a certain period of time (delayed operation time) after the switch SW is turned off. Therefore, when the user turns off the switch SW to leave the bathroom, the ventilation fan load 4 operates for a certain fixed period of time. In this way, forgetting to turn on or turn off the ventilation fan load 4 can be prevented,
I forgot to turn on the ventilation fan load 4, which caused damage to the bathroom.
It can prevent mold from growing in the bathroom. FIG. 6 shows the above-mentioned timing chart. FIG. 6a shows the operation of the switch SW, FIG. 6b shows the lighting load 1, and FIG. 6c shows the ventilation fan load 4. In addition, by using a pulse count type IC to set the delay time,
It not only has high time accuracy but also allows for miniaturization, and even with a long timer, the delay time can be checked in a short time.

FIG. 7 shows a perspective view of a switch body using this circuit, in which a body 11 housing each of the circuits described above and a cover 12 placed over the top surface of this body 11 are assembled using an assembly frame 13. A switch operation plate 14 for turning on and off a switch SW is swingably provided on the cover 12.

[Effects of the Invention] As described above, the present invention includes a switch that connects a lighting load to an AC power source through an on-side terminal and a common terminal, and a switch that connects a ventilation fan load and a switching element through an off-side terminal and a common terminal of this switch. A power control circuit in which a series circuit is connected to the AC power supply, an input terminal of a diode bridge is connected between both ends of the switching element, and a power supply terminal is connected to the output terminal of the diode bridge via a resistor to supply power. A switch element connected between a timer circuit that creates a certain delay time from the output terminal of the diode bridge and the output terminal of the diode bridge is turned on by a delay signal during the delay time operation of the timer circuit, and the switching element of the power control circuit is turned on. A trigger signal is applied via the diode bridge to perform on-control driving, and another switch element connected in parallel to the resistor is turned on to maintain power supply to the timer circuit via another switch element. It consists of a switching circuit that turns off the power control circuit and turns off the ventilation fan load using a time-up signal, so when the switch that lights the lighting load is turned from the on state to the off state, the timer circuit operates for a certain delay time. The power control circuit is controlled by the signal from the switch via the switching circuit to drive the ventilation fan load. Therefore, one switch can perform appropriate operations for the lighting load and ventilation fan load in a bathroom or toilet, for example. It has the effect that it can be carried out. In addition, since semiconductor elements such as timer ICs and switching elements are used instead of current transformers as in the past, cost reduction and miniaturization are easy.
Since the ventilation fan load is not driven while the bathroom or toilet is in use, it has the effect of not being cold in winter or making noise from the ventilation fan load, and since it is configured as above, the ventilation fan load can be controlled on and off. Power for the timer circuit can be obtained from both ends of the switching element of the power control circuit, making it possible to use a two-terminal structure that is inserted between the off terminal of the switch and the non-power side end of the ventilation fan load. This has the advantage that the wiring of the ventilation fan and the operation circuit of the ventilation fan can be easily modified.

[Brief explanation of the drawing]

Fig. 1 is a specific circuit diagram of the present invention, Fig. 2 is a block diagram of the same as above, Fig. 3 is a block diagram of the timer IC as above, Fig. 4 is a timing chart of same as above, and Fig. 5 is a thyristor SCR as above. FIG. 6 is a timing chart showing the operating condition of the above switch, and FIG. 7 is a perspective view of the main body of the switch. 1 is a lighting load, 2 is a timer IC, 3 is a timer circuit, 4 is a ventilation fan load, 5 is a power control circuit, 6
indicates a switching circuit, SW indicates a switch, and AC indicates an alternating current power supply.

Claims (1)

[Claims] 1. A switch that connects a lighting load to an AC power supply through an on-side terminal and a common terminal, and a series circuit of a ventilation fan load and a switching element connected to the above-mentioned AC power supply through an off-side terminal and a common terminal of this switch. a power control circuit in which the input terminal of a diode bridge is connected between both ends of the element;
A timer circuit whose power supply terminal is connected to the output terminal of the diode bridge through a resistor to create a certain delay time from power supply, and a switch element connected between the output terminal of the diode bridge to delay the timer circuit. It is turned on by a delay signal during time operation, and a trigger signal is given to the switching element of the power control circuit via the diode bridge to perform on-control driving, and another switch element connected in parallel to the resistor is turned on, thereby causing another switching element to turn on. A switch circuit for a ventilation fan comprising a switching circuit that maintains power supply to a timer circuit through a switch element of the timer circuit, and turns off a switching element of a power control circuit based on a time-up signal of the timer circuit to turn off a ventilation fan load.