JPS5926854B2 - Ventilation fan interlocking device for gas appliances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ventilation fan interlocking device for gas appliances, which automatically operates the ventilation fan in conjunction with the use of gas appliances.
This system aims to improve safety by detecting the presence or absence of load current in the ventilation fan, issuing an alarm when the ventilation fan is not operating, and shutting off the gas.

Conventionally, ventilation fan interlocking devices only operate the ventilation fan automatically in conjunction with the use of gas appliances, or issue an alarm when you forget to turn on the ventilation fan, and shut off the gas when there is a power outage or you forget to turn on the ventilation fan. Because of this, gas appliances could still burn even when the ventilation fan was not working, creating problems in terms of ventilation safety.

The present invention solves the above-mentioned conventional problems.

Embodiments of the present invention will be described below based on the drawings.

1 is a power source, 2 is a power supply circuit, 3 is a combustion detection circuit consisting of a voltage comparator (4) which inputs the output voltage of a combustion detection element 5 for detecting a combustion flame, and 6 is a voltage comparator (2) 7. An oscillator, 8 a delay timer circuit, 9 a delay circuit that receives the AC drive output signal of the voltage comparator (1) 4, and 10 a voltage comparator (3) 11 that receives the output of the delay circuit 9 as an input. 12 is a fuel valve drive unit, and 13 is a fuel valve.

14 is an ignition confirmation detection circuit for gas appliances that receives the AC drive output signal of voltage comparator (1) 4; 15 is a switch that closes in conjunction with the ignition of the main burner (hydraulic responsive switch, etc.); 16 is an ignition confirmation circuit; A relay that operates when the detection circuit 14 and switch 15 are turned on, 17 a relay contact that closes when the relay 16 operates, 18 a ventilation fan, 19 a switch with a built-in ventilation fan (pull string switch), 20 a load current of the ventilation fan 18 The transformer 21 installed in the flowing circuit is a voltage comparator + (4
) 22, 23 is a switching circuit that is turned on when the detection circuit 21 does not detect the secondary output voltage of the transformer 20, 24 is a switching circuit that is turned on when the ignition confirmation detection circuit 14 is on, and 25 is an alarm. It is.

The combustion detection element 5 and the fuel valve 13 are built into the gas appliance, and are ignited by some method to send the combustion flame to the combustion detection element 5.
The fuel valve 13 is provided with a switch 15 which can be pressed and held by operating a cock and which is closed in conjunction with the ignition of the main burner.

26 is a transformer of the power supply circuit 2 and has low voltage terminals 26a and 26b.
has.

27 is a full-wave bridge rectifier diode, 28 is a smoothing capacitor, 29 is a resistor, and 30 is a constant voltage diode.

The power supply circuit 2 is composed of the above components, and has output terminals A, B, and C.
has.

4 is a voltage comparator (1) having power supply terminals 4a, 4b, input terminals 4c, 4d, and output terminal 4e.

31. 32, 33, 34, 35 are resistors and voltage comparator 1 (
It is connected to input terminals 4c and 4d of 4.

The resistances of the combustion detection elements 5 and 36 are connected between the input terminals 4cm4d.

The combustion detection circuit 3 includes a resistor 37 and a transistor 38.

The delay timer circuit 8 is composed of a resistor 39, a diode 40, and a timer capacitor 41.

7 is a voltage comparator 2 with power terminals 7a, 7b and an input terminal 7e.
have.

42 is a resistor, 43 is a capacitor, 44 and 45 are resistors, 4
6 is a resistor, 47 is a diode, 48 is a resistor, 49 is a diode, 50 and 51 are resistors connected to the transistor 38, and resistors 42 and 44 are connected to the voltage comparator (2) using the voltage across the timer capacitor 41 as a power source. oscillator 6 with 7
Configure.

A transistor 38 is driven at the oscillation frequency of the oscillator 6.

52 is a diode, 53 is a resistor, 54 is a timer capacitor, and 55 is a resistor, which constitute a delay circuit 9 which receives the AC drive output signal from the output terminal 4e of the voltage comparator (1) 4.

11 is a voltage comparator 3 having power supply terminals 11a, 11b, input terminals 11c, 11d, and an output terminal 11e.

56, 57, 5B, 59, and 60 are resistors, and 61 is a diode, and the discharge type timer circuit 10 is constituted by the above-mentioned components.

The discharge type timer circuit 10 inputs the voltage of the timer capacitor 54 of the delay circuit 9 to the input terminal of the voltage comparator (3) 11, and the diode 61 connected to the output terminal 11e.
It is connected to the input terminal 4d of the voltage comparator (1) 4.

62 and 63 are resistors, 64 is a diode, 65 is a resistor, 6
6 is a diode, 67 and 68 are resistors, 69 and 70 are transistors, 71 and 72 are resistors, and 73 is a coupling capacitor, forming a power amplification circuit, which is connected to a transformer 74.

75 and 76 are rectifying diodes, 77 is a smoothing capacitor, 78 is a resistor, and the fuel valve driving section 12 is composed of the above-mentioned parts.
It has output terminals RI and E.

14 is an ignition confirmation detection circuit which inputs the AC drive output signal of voltage comparator (4), and includes a diode 81, a smoothing capacitor 82, and a resistor 83 connected to the connection point between diodes 64 and 66 of the fuel valve drive unit 12. and 84, transistor 85
Consists of.

86 is a diode for preventing back electromotive force of the relay 16.

87 is a half-wave rectifier diode connected to the secondary side of the transformer 20, 88 is a smoothing capacitor, 89 is a resistor, 90 and 91 are resistors, 92 is a timer capacitor, 93, 94 .
95 is a resistor, which is connected to the power supply terminal 22a of the voltage comparator (4) 22.
, 22b, input terminal 22C, 22d, and output terminal 22e to form the detection circuit 21.

The switching circuit 23 is constituted by resistors 96 and 97 and transistors 98.

99 and 100 are resistors, and 101 is a transistor, which constitute a switching circuit 24, and are connected to be turned on when the ignition confirmation detection circuit 14 is turned on.

102 is a diode, 103 is a resistor, and 104 is a capacitor. The resistor 103 and the capacitor 104 protect the voltage applied to the alarm 25.

105 is a diode connected to the F terminal of the delay timer circuit 8 in order to block the power supply to the timer capacitor 41 which is the power source of the oscillator 6 when the switching circuit 23 is on, and to stop the oscillation of the oscillator 6. It was established in

106 and 107 are manual switches that operate simultaneously.

Next, the operation will be explained.

The power supply circuit 2 is reduced to a low voltage by a transformer 26, full-wave rectified and smoothed by a full-wave bridge diode 27 and a smoothing capacitor 28, and made constant by a voltage regulator diode 30.

A constant voltage power source is obtained between output terminals A and B, and a low voltage power source is obtained between output terminals CB.

In the delay timer circuit 8, the timer capacitor 41 is charged through the resistor 39, and is stored up to c4.

■O4 is used as a power source, and resistors 42, 44, 45 are connected.

The voltage comparator (2) 7 operates at an oscillation frequency based on the time constant set by 46.48 and the capacitor 43, and the transistor 38 is engaged.

Here, C43゜R4□(!: C43'R45's respective time constants and resistance values R4□, R44, R45,
By appropriately setting R4, 6, and R48, it is possible to obtain an oscillator 6 that operates at a square wave duty 1:1 oscillation frequency.

In the combustion detection circuit 3, when the combustion detection element 5 is not heated, even if the transistor 38 is engaged at the oscillation frequency of the oscillator 6, the output terminal 4e of the voltage comparator (J) 4 is L(
on), the fuel valve drive unit 12 does not operate and the winding 80 of the fuel valve 13 is not energized.

When a thermoelectromotive force is generated in the combustion detection element 5 and an input voltage is applied to the input terminal 4c, the potential of 4c becomes lower than the potential of 4d, so that the output terminal 4e becomes H (off).

However, since the alternating current component of the oscillator 6 is superimposed between the input terminals 4c and 4d, the voltage across R36 is applied alternating current, and the output terminal 4e repeats L (on) and H (off) and is not related to the oscillation frequency. move and operate.

When the output terminal 4e is L (on), the transistor 69 is turned on, and when the output terminal 4e is H (off), the transistor 70 is turned on.
Transistors 69 and 70 are alternately turned on and off, causing alternating current to flow through coupling capacitor 73 to transformer 74.

Full-wave rectification and smoothing are carried out on the secondary side of the transformer 74.
DC power is obtained and the winding 80 of the fuel valve 13 is energized.

By energizing the winding 80, the electromagnet 79 of the fuel valve 13 pressed by the cock operation is attracted and held.

On the other hand, the output terminal 4e of the voltage comparator (4) is H (off).
At this time, the signal is input to the delay circuit 9 through the diode 52.

The voltage of the timer capacitor 54 is divided by the resistors 53 and 55, and increases with a time constant determined by R53, R5°, and C54, and the voltage is applied to the input terminal 11c of the voltage comparator (3) 11.
The reference voltage (1
1d input voltage), the output terminal 11e becomes L.
(on).

When the pilot flame is ignited and 11e is turned on at the set time constant, the reference voltage at the input terminal 4d of the voltage comparator (1) 4 becomes low and reaches the misfire detection level, indicating that, for example, the combustion flame has misfired. In such cases, it can be shut off quickly.

Also, when 4e is H (off), it is input to the ignition confirmation detection circuit 14 through the diode 81, and the capacitor 82
After the pilot light is ignited and the transistor 85 is turned on, in the case of a water heater, the switch 15 is closed in response to the water pressure by flowing water, and the main burner is ignited.

When the switch 15 is turned on, the relay 16 is activated, the relay contact 17 is turned on, and the ventilation fan 18 is energized.
If the ventilation fan built-in switch 19 is on, the ventilation fan 18
starts.

Upon starting, a load current flows through the transformer 20 and an AC output voltage is generated on the secondary side.

The output voltage is half-wave rectified by a diode 87, smoothed by a smoothing capacitor 88, and resistor 89 is used as a load resistance for G, H.
Applied between terminals.

On the other hand, the reference voltage set by the resistors 93 and 94 is applied and set to the single power terminal 22c of the voltage comparator (4) 22, and the resistor 90 is applied to one input terminal 22d after the switch 15 is turned on. .89, the timer capacitor 92 is charged using the resistor 91 as a load resistance, and the voltage at the H terminal increases.

However, since the load current of the ventilation fan flows and a voltage is applied between the G and H terminals, the potential at point H (the potential at 22d) is lower than the potential at 22C.

Therefore, the output terminal 22e of the voltage comparator (4) 22 is L
(on), and the transistor 98 of the switching circuit 23 remains off.

Therefore, the alarm device 25 is not energized and no alarm is generated.

However, if you forget to turn on the ventilation fan built-in switch 19, no load current flows through the transformer 20 and no output voltage is generated on the secondary side, so no voltage is applied between the G and H terminals.

Therefore, the potential of 22d of H terminal is C9□, R9□ and R
8'; J, R, When the capacitor 92 is charged with the charging characteristics set by 90 and the potential of 22d becomes higher than the reference voltage 22c, the output terminal 22e of the voltage comparator (4) 22
becomes H (off).

When it becomes H (off), the switching circuit 23 is biased to the transistor 98 through the resistors 95, 96, 97, and the transistor 98 is turned on.

On the other hand, since the ignition confirmation detection circuit 14 is on, the switching circuit 24 is on, so the alarm 25 is energized and an alarm sounds.

At the same time, the potential at point F of the delay timer circuit 8 is lowered through the diode 105, short-circuited, and the charging current that has been flowing to the capacitor 41 until now is blocked through the resistor 39, thereby stopping the charging current of the capacitor 41.

Then, Vo41 starts discharging and the resistance becomes 42°44.45.
, 46, 48, and the voltage comparator (2
)7, the oscillator 6 is oscillating at the input terminal 7c.
, 7d, so the oscillation is stopped.

Then, the transistor 38 also stops oscillating, and the voltage comparator (
J) The alternating current component is no longer superimposed on 4, and the fuel valve drive unit 1
The alternating current component of 2.\ is not applied, the current to the winding 80 is cut off, the fuel valve 13 is closed, and the gas is cut off.

Even if the gas is cut off, the switch 15 remains on because it responds to water pressure.

However, due to the gas cutoff, there is no input to the ignition confirmation detection circuit 14, the transistor 85 is turned off, the switching circuit 24 is turned off, the power supply to the alarm device 25 is cut off, and the alarm is stopped.

In short, the ventilation fan is started in conjunction with the use of gas appliances, and when the ventilation fan is not working, such as when you forget to turn on the ventilation fan, it activates the alarm and shuts off the gas.

Also, if you notice the alarm and turn on the ventilation fan built-in switch 19, the load current will flow to the transformer 20, and the voltage comparator (4) will flow to the transformer 20.
) 22 becomes L (off), the transistor 98 of the switching circuit 22 turns off, and the alarm 25
・By cutting off the power to \, automatically stopping the operation of the alarm 25, and re-energizing the capacitor 41, the appliance can be used as is without cutting off the gas.

As is clear from the above description, the present invention provides the following effects.

(1) By operating a voltage comparator that inputs the output voltage of a combustion detection element that detects combustion flame, and by superimposing the oscillation frequency of an oscillator and applying an alternating current component to the fuel valve drive unit, all kinds of Safety against parts failure and fail-sale performance can be ensured.

(2) By matching the oscillation frequency of the oscillator 6 with the resonant frequency of the resonant circuit of the coupling capacitor 73 and the transformer 74, a sine wave alternating current can be obtained and the efficiency of the transformer 74 can be utilized to the maximum. It is possible to obtain a large amount of flow with a small transformer.

(3) Since the output voltage of the combustion detection element is applied to the input of the voltage comparator, the voltage comparator can be operated at several mV, so the response speed can be increased.

(4) By detecting the load current when the ventilation fan is not operating, the alarm can be activated and the gas can be shut off, further improving safety, and in the event of a power outage, the fuel valve will not be energized and the gas will be shut off. , which is more secure.

(5) Since the misfire response is faster, the time for gas outflow is shorter than in the past, making it safer.

(6) Even if the switch 15 operates in response to water pressure, the ventilation fan will not operate when only water is used, and the ventilation fan will always be activated after ignition of the pilot flame, so when only water is used, the ventilation fan will not operate. This eliminates the need to operate the ventilation fan unnecessarily.

(7) By turning on the manual switches 106 and 107, the ventilation fan can be operated regardless of the linked gas appliances. Even at that time, if you forget to turn on the ventilation fan switch, the alarm will be activated and the necessary When operating the ventilation fan without using the ventilation fan, the load current to the ventilation fan is detected to further improve safety.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. 2...power supply circuit, meter...combustion detection circuit,
4. voltage comparator (1), 5... combustion detection element, 6. music oscillator, 7... voltage comparator (2)
, 8...delay timer circuit 9...delay circuit, 10...discharge type timer circuit, 11...
... Voltage comparator (3), 12 ... Curved fuel valve drive section, 13
...Fuel valve, 14...Curved ignition confirmation detection circuit, 1
5... Switch, 16... Hat rule, 18...
- Curved ventilation fan, 20... Transformer, 21... Curved detection circuit, 22... Voltage comparator (4,), 23.
...Switching circuit, 24...Switching circuit, 25...Switching circuit, 62-73...
・Constructs a power amplifier circuit, 69, 70... Switching element, 73... Surface coupled capacitor, 74...
...transformer.

Claims (1)

[Claims] 1. A combustion detection element that detects a combustion flame, a voltage comparator 1 that inputs the output voltage of this combustion detection element, and a voltage comparator 2 that superimposes an alternating current component on this voltage comparator 1. and a fuel valve drive unit that operates at the oscillation frequency of the oscillator in response to the operation of the voltage comparator 1 to control the fuel valve, and a delay circuit that receives the AC drive output signal of the voltage comparator 1 as input. and a voltage comparator 3 whose input is the delay circuit, and the output of the voltage comparator 3 is input to the voltage comparator 1.
In addition to providing a combustion safety device connected to the reference voltage terminal of the gas appliance, a detection circuit to confirm the ignition of the gas appliance, a switch that closes in conjunction with the ignition of the main burner, and a relay that is activated upon ignition and ignition confirmation are provided. , the ventilation fan is configured so that the ventilation fan is started by the operation of this relay, and the circuit through which the load current of the ventilation fan flows includes a detection circuit having a voltage comparator 4 that detects the secondary side output voltage of the transformer as input, and the detection circuit is disabled. A switching circuit that is turned on when activated is provided in an alarm circuit connected through the switching circuit that is turned on when ignition is detected by the ignition confirmation detection circuit, and the oscillation of the oscillator of the combustion safety device is stopped. Ventilation fan interlocking device for appliances. 2 In the fuel valve drive unit, when the output state of the voltage comparator 1 driven by the oscillation frequency of the oscillator is L (ON), charging is performed through one switching element and the coupling capacitor, and when the output state is H (OFF), the output state is charged through the other switching element and the coupling capacitor. A patent claim comprising a combustion safety device comprising a fuel valve drive unit which couples a transformer to a power amplifier circuit configured to discharge through a switching element and a coupling capacitor, and obtains a DC component on the secondary side thereof. A ventilation fan interlocking device for gas appliances according to item 1. 3. The power amplification circuit includes a combustion safety device that matches the initial vibration frequency of the IC resonance of the coupling capacitor and the transformer with the oscillation frequency of the oscillator to obtain a sinusoidal alternating current in the transformer. The ventilation fan interlocking device for gas appliances according to item 2. 4 The L (ON) output of the voltage comparator 3 causes the voltage comparator 1 to make the misfire detection level of the combustion flame higher than the ignition detection level of the output voltage of the combustion detection element, and to speed up the misfire detection. A ventilation fan interlocking device for gas appliances according to claim 1, comprising a combustion safety device connected thereto.