Hazardous area warning device

Photocoupler

Circuit Operation Principle The danger zone warning circuit consists of a voltage regulator circuit, a pyroelectric infrared detection trigger circuit, an electronic switch circuit, a voice circuit, an audio power amplifier circuit, a low frequency oscillator and a flash drive circuit, as shown in Figure 8-121. Show.

The voltage regulator circuit is composed of a three-terminal voltage regulator integrated circuit IC2, a resistor R3, a Zener diode VS and a filter capacitor Cl, C2.
The pyroelectric infrared detection trigger circuit is composed of pyroelectric infrared detection module ICl, transistors Vl, V2, resistors Rl, R2 and potentiometer RP.
The electronic switch circuit is composed of an electronic switch integrated circuit IC5, resistors R9, R10 and a capacitor C8.
The audio power amplifying circuit is composed of a power amplifying integrated circuit IC4, resistors R6-R8, capacitors C4-C7 and a speaker BL.
The low frequency oscillator circuit is composed of a time base integrated circuit IC6, a resistor Rli, a Rl2, a capacitor C9, a ClO, and the like.
The flash drive circuit is composed of a transistor V3, resistors R13-Rl5, field effect transistors VF1", V" and indicator lamps HL1, HL2.
+l2V voltage is directly supplied to IC4, 1C5 and V2; the other is regulated by IC2 to +5V, which is supplied to IC1; and one way is regulated by R3 and VS is regulated, and +3V voltage is supplied to IC3.
The ICl is composed of a high-sensitivity infrared sensor, a high-gain low-noise amplifier, an automatic temperature compensation circuit, a signal comparison and discrimination circuit, a delay circuit, and a high-low-level driving circuit.
In the static (in person detection area), lC1's 1 pin outputs low level, 2 pin outputs high level, transistors Vl and V2 are both turned off, the language circuit does not work, the speaker BL does not sound; the electronic switch circuit is off In the off state, the low frequency oscillator has no working power and does not work, and HLl and HL2 do not emit light.
When someone stuns the detection area of ​​ICl, I1's pin 1 changes from low level to high level, making Vl turn on, IC3 is triggered to work, and the output signal (O/P end) outputs the voice signal through IC4. After zooming in, the speaker BL is driven to emit a "xx dangerous, never close" language alert. At the same time, the 2 pin of ICl changes from high level to low level, so that V2 is turned on, the electronic switch inside IC5 is turned on, the low frequency oscillator gets the working power and oscillates, and the output frequency from the 3 pin of lC6 is 2Hz low-frequency pulse signal makes HLl and HL2 alternately flash (when the signal is positive pulse, VFl is turned on, HLl is lit; when the signal is negative pulse, V3 and VF2 are turned on, VFl is cut off, H愧 is lit ), a flashing reminder signal is issued.
Component selection
Rl-R7, R9-Rl5 select 1/4W carbon membrane resistor or metal membrane resistor for use; R8 selects 1/2W metal membrane resistor for use.
The RP uses a small potentiometer or a variable resistor.
Cl, C2, C4-C6, C8 and C9 all use small aluminum electrolytic capacitors with a withstand voltage of lOV or higher; C3, C7 and ClO use polyester capacitors, monolithic capacitors or CBB capacitors.
Vl selects S9014 or 3DG9014 type silicon NPN transistor for use; V2 and V3 select S9012 or 3DG9012 type silicon PNP transistor.
VFl and VF2 use 2SK1530 or IRFl390 type field effect transistors.
ICl selects HN9llL pyroelectric infrared detection module (detection distance is lOm, azimuth angle is 100°); lC2 selects LM7805 type or 78叨5 type three-terminal integrated voltage regulator; IC3 selects internal storage "xx dangerous, please do not approach "The language integrated circuit; IC4 selects TDA2002 type audio power amplifier integrated circuit; IC5 selects WH8778 type electronic switch integrated circuit; IC6 selects NE555 type time base integrated circuit.
BL uses 8Ω (or 4Ω), 3-5W electric speakers.
HLl and HL2 use l2V light bulbs for motor vehicles.