JPS5822024Y2 - Ventilation fan alarm switch mechanism - Google Patents

Description

[Detailed description of the invention] This invention consists of a switching circuit and an alarm circuit that automatically operate the ventilation fan when using gas appliances, etc., and also drive the alarm when the ventilation fan manual switch is not turned on. This invention relates to a ventilation fan alarm switch mechanism.

Conventionally, there was an interlocking switch mechanism that linked the ventilation fan to ventilate when using gas appliances, etc., but even if the interlocking switch worked, the ventilation fan would not operate if the ventilation fan body switch was in the "off" state. There were drawbacks.

This invention was made to improve the above-mentioned drawbacks, and supplies power to the ventilation fan through a half-open contact that operates in response to a pressure switch operated by gas pressure and an internal switch for manually switching the ventilation fan. In an electric circuit, a transformer is connected in series with a ventilation fan so that the transformer core is magnetically saturated with a minute current in the power supply circuit and the secondary voltage is approximately constant, and an alarm that switches depending on the presence or absence of the secondary voltage. The present invention provides a ventilation fan alarm switch mechanism in which a circuit is connected between the half-open contact and the changeover switch.

Hereinafter, embodiments of this invention will be described in detail based on the attached drawings.

FIG. 1 is an electric circuit diagram according to this invention, and the electric circuit for driving the ventilation fan 1 is formed by a power source 2, an automatic changeover switch 3, a body switch 4, and a transformer 5 for detecting a load.

The secondary circuit 6 of the transformer 5 includes a base 7a of a transistor 7, a base limiting resistor 8°, a rectifying diode 9, and a reverse voltage applying diode 1 of the transistor 7.
0 is connected.

Further, the collector 7b of the transistor 7 has a rectifying diode 11. It is connected to one end of the electrical circuit via a resistor 12, and the branch line of the collector 7b is connected to the other end of the electrical circuit via a resistor 13.14 and a capacitor 15 connected in parallel to this resistor 14.

Further, the automatic changeover switch 3 of the electric circuit has a manual side terminal 3a and an automatic side terminal 3b.
An alarm device 16 such as a buzzer is connected to the thyristor 17 via a thyristor 17, and the gate N7a of the thyristor 17 is
It is connected between the resistors 13 and 14 described above.

On the other hand, a gas pressure switch 18 that operates in response to gas pressure from gas appliances, etc. is connected to a transformer relay 19, and a normally open contact 20 connected to this transformer relay 19 is connected to the automatic side terminal 3b of the automatic changeover switch 3. has been done.

FIG. 2 is a characteristic diagram of the transformer 5, in which the transformer core is magnetically saturated where the negative secondary current is small, thereby reducing changes in the secondary voltage.

The operation of the electric circuit of the ventilation fan according to the invention constructed as above will be explained.

First, when using a gas appliance with the automatic changeover switch 3 positioned at the automatic side terminal 3b, the gas pressure switch 1
The contact point 8 is closed, and the ventilation fan 1 is supplied with power and starts rotating.

At this time, a load current flows through the primary side of the transformer 5, and a voltage as shown in FIG. 2 is generated in the secondary side circuit 6 of the transformer 5.

Due to this voltage, a voltage is applied to the base 7a of the transistor 7 through the base limiting resistor 8 and the rectifying diode 9, so the transistor 7 becomes conductive, and if the internal resistance of the transistor 7 is ignored, the potential of the collector 7b will be the same as that of the emitter. Since the potential becomes "zero" which is the same as the potential, no current flows through the gate 17a of the thyristor 17.

Therefore, the alarm device 16 such as a buzzer is not activated since the cyrisk 17 is not energized.

Here, if the body switch 4 of the ventilation fan 1 is disconnected, the motor of the ventilation fan 1 has a failure, or the electric circuit of the ventilation fan 1 has a breakage or other failure, the transformer 5 Since no load current flows to the primary side and no voltage is generated in the secondary side circuit 6, the base 7a potential of the transistor 7 becomes zero, and the transistor 7 becomes non-conductive.

Therefore, the rectifier diode 11. Resistors 12, 13 and 14, capacitor 15
Since a voltage divided by the voltage is applied and a current flows through the gate N7a, the thyristor 17 becomes conductive, and the alarm 16 such as a buzzer is activated, so that the ventilation fan can be automatically operated when the gas appliance is used.

If the automatic changeover switch 3 is switched to the manual side terminal 3a, the ventilation fan 1 can be operated arbitrarily regardless of the operation of the gas pressure switch 18, so that it can be used as a normal indoor ventilation fan.

As described above, according to this invention, if the ventilation fan is stopped when gas appliances are in use, an alarm is issued, and by connecting a transformer to the circuit through which the ventilation fan's load current flows,
As described above, a stable secondary voltage can always be supplied to the switching circuit regardless of the magnitude of the load current, that is, regardless of the type of ventilation fan.

In addition, compared to the method of detecting load current using a constant voltage drop of a diode, there is no waveform distortion of the power supply, and there is no effect such as voltage fluctuations on the ventilation fan motor.
It can ensure stable rotation, and has a practical effect as a ventilation fan alarm switch mechanism.

[Brief explanation of drawings]

Figure 1 is an electrical circuit diagram showing an embodiment of this invention;
The figure is a characteristic diagram of the transformer based on this invention. 1... Ventilation fan, 2... Power supply, 3...
...Automatic changeover switch, 3a...Manual side terminal, 3b...Automatic side terminal, 4...Instrument switch, 5...Transformer, 6 ...Secondary side circuit, 7...Transistor, 7a...
・Base, 7b...Collector 8...
・Base limiting resistor, 9... Rectifying diode, 10... Diode for applying reverse voltage, 11...
... Rectifier diode, 12, 13, 14...
...Resistor, 15...Capacitor, 16...
...Alarm, 17...Sirisk, 17a...
...Gate, 18...Gas pressure switch, 1
9...Transformer relay 20...Normally open contact.

Claims (1)

[Scope of utility model registration request] In an electrical circuit that supplies current to a ventilation fan through a normally open contact and a manual/automatic changeover switch that operate in response to a gas pressure switch that responds to the gas pressure of a gas appliance, etc., a transformer core is applied to the electrical circuit with a minute current. Connect a transformer in series that saturates the voltage so that the secondary voltage is almost constant, and connect a switching circuit that drives an alarm such as a buzzer depending on the presence or absence of the secondary voltage to the automatic side terminal of the manual/automatic changeover switch. A ventilation fan alarm switch mechanism characterized by being connected to form an alarm circuit.