6 gas alarm circuit diagrams, working principles


Gas alarm circuit diagram (1)


When using gas fuel, you must pay attention to safety. If accidents (such as water overflow) cause gas to turn off, and the kitchen will cause a lot of gas leaks when unattended, it is easy to form fire and personal injury accidents. If the gas turning the alarm is used, once the gas turns off, it will make a alarm sound to remind people to deal with it in time. The circuit of the gas turning the alarm is shown in the figure. The circuit is mainly composed of the alarm and music integrated circuit Y976 and a small amount of separate components.

The alarm integrated circuit Y976 The function of each foot is: 1 foot is OUT out of the alarm signal output end; 2 and 3 feet are set to SL and S2 for the alarm sound. When SL and S2 are suspended, the alarm sounds are 4 / s BP BP. The sound of the machine; when the SL is grounded, the S2 is suspended, the sound of 1 sound / s BP machine; when the SL is suspended, the S2 ground is grounded, the “beep” sound of 1 sound / s; EN, when EN is low -power, the circuit does not work; when the EN end is high level (not less than 0.4VDD) or suspended, the circuit work output alarm sound; Change the value of the external resistance between 6 and 7 feet, which can adjust the frequency of the alarm sound; the 8 pin is the power supply positive VDD).

In the circuit, RG is a photoresistor resistor, which is used to detect whether the burning flame is. When burning is normal, RG is low -resistant by the flame light, and its resistance value is generally below LOKQ. It provides sufficient base bias current to the triode VT through the RP and the VT is used to make VT saturated. The setting of the collector output is low, so that the envelope of the alarm integrated circuit A is in a low level, so the collection of block A does not work, and there is no alarm sound output. If the gas extinguishes due to an accident, the RG immediately shows a high resistance. It is not enough to maintain VT with the RP. In the level, the piezoelectric speaker B emits a alarm of 4 -sound / s similar to the alarm of the BP machine to remind the owner to deal with it. RL and C form a short -term delayed circuit, which has the effect of inhibiting flame fluctuations that may cause errors on circuits.


Gas alarm circuit diagram (2)

The alarm circuit is simple and reliable. When the flammable gas reaches the dangerous concentration, the internal resistance of the gas -sensitive element becomes small, the current flows through the potentiometer W increases, the thyristor SCR is triggered, the bee tweee issues alarm, the thermal resistance RT RT is RT, and the thermistor RT RT is RT. Make temperature compensation.


Gas Alarm Circuit diagram (3) Photosami gas alarm

The soup overflowing the soup with gas or liquefied gas is easy to extinguish the stove fire, and the gas leaks the room, causing serious losses of life and property. Installing a gas alarm can effectively prevent the occurrence of accidents. The commercially available gas alarm uses gas leakage alarms. Here is a novel light -sensitive gas alarm that uses music cards to send vocal audio. The materials are small, simple to make, and small power consumption. Generally, as long as the component is reliable, no debugging is required after the production is successful. Essence

working principle:

When the gas stove is burned normally, the alarm is in a standby work. DG1 Photosamidity triode is in a low -resistance state by the flame. BG2 is turned on, and the music vocal sheet is not working at a low potential, and the speaker does not sound. Once the gas stove suddenly flames, the light -sensitive triode loses the light irradiation, its internal resistance is increased, BG2 turns from saturation to the end, and the music integrated block triggers work. Gas poisoning accidents occur.


Gas alarm circuit diagram (4)

As shown in the figure, the gas turning the alarm circuit is composed of flame detection circuits, amplifying plastic surgery circuits, and alarm circuits. The anti -phase device in the circuit is CD4069.

Gas alarm circuit diagram (5)

Gas gas alarm circuit diagram: This device is in a detection state after litting gas. Once the gas stove is turned off by itself, it can automatically ignite and issue a music alarm.


The principle of circuit is shown in Figure 1 The switch S is connected with the gas stove. When the gas is turned on, the switching S is closed. If the gas is not ignited at this time, the light -sensitive resistance R2 is in a high resistance state. The transistor VT1 is turned on to trigger the work of music integrated circuits and emit music. At the same time, the pulse voltage with a peak of 120VPP output of the transformer T1 is charged through the R5 via C1, and the VD1 is charged by C2. When C1 reaches a certain voltage, triggers VD2 is turned on, and the thyristor is conducted, so that the charging C2 is discharged through the primary and thyristor of the T2. As a result, 5-10kV high voltage in T2’s secondary induction, discharged from the tip of the discharge needle, and ignited gas. After the gas was ignited, the light -sensitive resistance was reduced by the flame irradiation resistance, resulting in the delay of VT1, stopped after the music was played, and the discharge also stopped. It can be seen from the circuit analysis that when the gas flame is extinguished again, the circuit will automatically ignite continuously and issue a music alarm.

This device consumes small electrical electricity, and generally two batteries can be used for more than half a year. The switching S can be installed with an appropriate itinerary switch with the gas stove switch. The music integrated circuit can use any one of the music for about 10 seconds. The optical resistance uses the MGL -45 type. It is fixed in a round tube during production, installed at 10cm from the flame and aimed at the flame. T1 uses the output transformer of a semiconductor radio, which is used upside down. VD1 uses a rectifier diode with more than 200V. VD2 is a trigger tube. The values ​​of C1 and C2 determine the discharge intensity and speed. 3CTS1 with a small touch current, 400V with resistance to 400V. T2 can be restructured with a 12 -inch TV line, remove the original low -voltage part, and use φ = 0.35mm high -intensity paint cables to around 15 turns on the original skeleton; the secondary high -voltage package can be removed from the rectifier. The discharge needle is made by the bicycle bar. It is appropriate to grind the tip at one end, and the two discharge needles should be 5mm. Diversion the switching S is connected to the gas, and adjust the R1 to make the VT1 intercept and turn on and. The igniter is installed in the free position of the gas stove, and the discharge is targeted at the quasi gas spray port.


Gas alarm circuit diagram (6) TRS-109 gas leakage alarm circuit diagram