CN104728150A - Ventilator timing switch - Google Patents

Abstract

The utility model relates to a timer switch capable of turning off the power supply at regular intervals. The on-off of the one-way thyristor is controlled by a timing circuit, and the on-off of the one-way thyristor controls the working state of the ventilation fan.

Description

Ventilation fan timing switch

technical field

The invention relates to a ventilating fan timing switch capable of timing off the power supply of the ventilating fan.

Background technique

At present, the known bathroom ventilator power switch is all manual. The shortcoming of this switch is: when entering toilet, open ventilation fan, finish using, close switch again after a period of time. The disadvantage of using this kind of ordinary switch is: once there is interference from other things, the switch cannot be turned off in time, so that the ventilating fan works for a long time, which not only shortens the service life of the ventilating fan, wastes electric energy, but also causes certain economic losses.

Contents of the invention

In order to overcome the shortcomings brought by the existing switch, the present invention provides a timing switch, which can not only be manually closed in time, but also can automatically cut off the power after a period of time if it cannot be manually closed in time, so as to prolong the service life of the ventilation fan , to save electricity and reduce economic losses.

The technical solution adopted by the present invention to solve the technical problem is: the power supply forms a closed circuit through a manual switch, a ventilation fan, a bridge rectifier diode and a one-way thyristor. Whether the ventilation fan works is controlled not only by the manual switch but also by the one-way transistor, and the on-off of the one-way transistor is controlled by the timing circuit. The timing circuit is mainly composed of NE555, a timing resistor and a timing capacitor. After the timing resistor and the timing capacitor are connected in series, the other end of the timing resistor is connected to the power supply, and the other end of the timing capacitor is grounded. The pin is grounded through an anti-interference capacitor, and pin 3 is the output terminal, which is connected to the control terminal of the unidirectional transistor through an isolation resistor.

The beneficial effects of the present invention are: the timing time is adjusted by adjusting the size of the timing resistor or the timing capacitor, so that the ventilating fan can be disconnected from the power supply within a certain period of time to stop working, thereby achieving the purpose of prolonging the service life of the ventilating fan and saving electric energy . Moreover, the circuit is simple and the performance is reliable.

Description of drawings:

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the schematic circuit diagram of the present invention.

Fig. 2 is the exterior view of the present invention

In the figure 1. Manual switch, 2. Ventilation fan, 3. Rectifier diode, 4. Rectifier diode, 5. Step-down capacitor, 6. Filter capacitor, 7. Discharge diode, 8. Timing resistor, 9. Manifold NE555, 10. Isolation resistor, 11. Rectifier diode, 12. Rectifier diode, 13. Step-down resistor, 14. Unidirectional transistor, 15. Zener diode, 16. Timing capacitor, 17. Anti-interference capacitor.

In Figure 1, the 220V lighting power is supplied to the ventilation fan (2) through the power switch (1), the bridge rectifier diodes (3), (4), (11), (12), and the one-way transistor (14) At the same time, after the 220V lighting power supply is rectified by the bridge type, the voltage is stepped down by the step-down capacitor (5) and the drop-down resistor (13), filtered by the capacitor (6), and the voltage is stabilized by the Zener diode (15) to supply power to the timing circuit.

When the manual switch (1) is closed, the power supply is rectified by the bridge rectifier diodes (3), (4), (11), (12), the capacitor (5) and the resistor (13) step down, and the capacitor (6) filters, The Zener diode (15) supplies power to the integrated block (9) after voltage stabilization. At the same time, the power supply charges the timing capacitor (16) through the timing resistor (8). At this time, due to the clamping effect of the timing capacitor (16), pins 2 and 6 of the integrated block (9) are at low level. At this time, the integrated block (9 ) pin 3 outputs a high level. The high level is added to the control pole of the one-way thyristor (14) through the isolation resistor (10), and the one-way thyristor (14) is turned on at this time, so the ventilation fan (2) passes through the bridge rectifier diode (3), ( 4), (11), (12), one-way thyristor (14), manual switch (1) form a circuit and start working.

As time goes on, when the charging voltage at both ends of the capacitor (17) reaches 2/3 of the power supply voltage, the pin 3 of the integrated block (9) changes from high level to low level, and the low level passes through the isolation resistor (10 ) to the control pole of the one-way thyristor (14), when the AC current crosses zero, the one-way thyristor (14) is cut off, and the ventilation fan (2) stops working.

In Figure 2, the manual switch (1) is used to turn on the ventilation fan or manually turn off the ventilation fan.

Claims (2)

1. A power supply timing switch, manual switch, ventilation fan, bridge rectifier circuit, one-way thyristor and power supply form a loop, the output end of the timing circuit is connected to the control pole of the one-way thyristor, it is characterized in that: the timing circuit is composed of NE555 and timing resistor , Timing capacitor composition. 2. The power timing switch according to claim 1, characterized in that: the anode of the unidirectional thyristor is connected to the negative pole of the bridge rectifier circuit, the cathode of the unidirectional thyristor is connected to the common terminal ground, and the control pole of the unidirectional thyristor is connected through the isolation resistor Connect with pin 3 of the output terminal of the integrated block NE555.