The circuit can also be used for security, the contact line VT1 gate installed in the door handle b

Takanori Hashimoto view of the world music musical brass door knockers toys IC chip doorbell IC chip IC toy duck voice IC voice chip called horse called world music six Christmas 12 Christmas 18 Christmas 20 phone ringing doorbell ring ding dong application circuit chip core company "bite , boom "sound of the doorbell electrical schematics. It is the use of a time-base circuit and peripheral components of the manifold. It's a beautiful sound realistic alignment simple brass door knockers and easy, low cost, a 6V battery can be laminated over three months, low power consumption. Figure IC is the time base circuit manifold 555, which constitutes astable multivibrator. Press the button AN (mounted on the door), oscillator, the oscillation frequency of about 700Hz, the speaker issued a "ding" sound. At the same time, the power to charge C1 through the diode D1. When you release the button, C1 will discharge through the resistor R1, sustain oscillation. However, due to the AN is disconnected, the resistor R2 is in series circuit, the oscillation frequency changes, is about 500Hz, the speaker "dong" sound. Until the voltage on C1 into oscillation can not be maintained until 555. Wrap the length of the "boom" sound can be changed by changing the value of C1. Without battery two-tone doorbell Http://www.atchip.com With increasing penetration of telephones, have home phone home more and more, but most residential telephone usage is low, use the telephone home feeders supplied 48V (60V) DC feed for electronic doorbell work energy is economical brass door knockers and practical. Now introduce a two-tone doorbell without the battery circuit. brass door knockers Schematic circuit as shown, is not difficult to see that the circuit diagram is a variant of conventional telephone ringing circuit. a, b are the home telephone line positive and negative at both ends. AN doorbell button is normally open, waiting at the phone, press the AN, PBX provides 48V (or 60V) voltage brass door knockers DC feed through VD1, R1 to charge the capacitor C1, when C1 terminal voltage Vc reaches of IC1 When the voltage from the control, IC1 start-up sent two-tone electronic ringing the buzzer B sound, inform the owner when guests are coming. And when the phone is in use, the figure a, b between the voltage from the control voltage brass door knockers is less than the lower reaches of IC1, this time, even if you press the doorbell button is not working AN This is because the value compared with R1 large, much larger than the impedance of the telephone. It has no effect on normal telephone calls when the AN pressed. No adverse effects on the PBX, only when the doorbell for incoming calls during busy. Analysis and improvement of a doorbell ring core public brass door knockers an intercom doorbell circuit shown, it works as follows: When the hook hook switch HS usually 1,2 contacts connected with AC220V power supply, V1 with DC output, this voltage is only for charging the battery, also added to the music of the IC feet. Such as click S, the music IC's foot triggered , feet musical output, amplified by V2 push speaker sound while driving through R5 Y2, Y3. After the hook, hook switch HS 1,3 contacts connected, call the circuit is powered, then can be intercom. The doorbell due to the high audio amplifier IC2 (LM386) gain, easy to Y2, Y3 produce howling. Actual verification by the author, as long as Y2, Y3 parallel across a few pF of small capacitors, howling can be removed. Without music doorbell button This paper describes a button without music doorbell, doorbell come before long standing, you can automatically send the doorbell. Music doorbell circuit schematic as shown in the drawings. IC1 and other components infrared transmitter circuit by IC1, RP, R1, C1 constitute a multi-harmonic oscillation frequency component data shown in the figure, the oscillation frequency of about 40kHz, output current is 100--200mA, can drive emits infrared light-emitting diode D1 40kHz modulated brass door knockers infrared pulses. IC2 is the infrared receiver chip, high sensitivity, high gain, good output waveform, and has a frequency discriminator function. D2 receives the infrared receiver frequency to 40kHz infrared pulse is converted to an electrical signal fed to the first IC2 pin , amplified, and C5, L tuning detector and the internal circuit IC2, after shaping, the output pulse from the first signal pin . When the ring core equity, IC2 first pin output low battery, D3 deadline, music IC IC3 no trigger pulse, no music signal output, speaker B does not sound. When someone standing in front of the block D1 transmit infrared signals, brass door knockers IC2 first potential instant brass door knockers feet from low to high, triggered by D3 IC3 output brass door knockers music signal, driven by V amplified speaker sound. IC1 use NE555, IC2 is μPC1373, IC3 selection of music IC 9300 series. D1 available SE303A or AC80E type 5mm round infrared light-emitting diode, D2 available PH302 square infrared receiver diode. V for 9013NPN tube, β 100. B selection YD58--1 type, 8Ω / 0.25W small-caliber brass door knockers speakers. L with 0.08mm high strength wire, on a small transistor brass door knockers radio IF transformer skeleton can be tightly wound 30 turns. Two kinds of non-button doorbell music doorbell ring core companies are required to install the installation, and thus there is trouble to install and easy to lose damage and other problems. Composite switches instead of mechanical trigger switch make music doorbell, you can overcome these drawbacks. Figure 1 is a vibration. When someone knocks hand, the piezoelectric ceramic sheet YD is mounted inside of the door is subjected to vibrations generated by a voltage brass door knockers corresponding to the audio, and the composite tube BG2 BG1 switch is turned on, the circuit CIC music playing a piece of music that is being triggered. Piezoelectric ceramics is appropriate to use a larger diameter, brass door knockers with 502 bonding glue to the center of the door biased brass door knockers position. brass door knockers Figure 2 is a touch. When your fingers touch the circuit with point A, human induced voltage of the composite tube BG1 and BG2 conduction, music circuit CIC triggered by some music that is played. Touch a metal plate available electrode A moderate size can be fixed on the door. Touch Touch doorbell doorbell ring core chip companies described in this article, instead of mechanical switches with touch mode, it is simple and reliable, practical and interesting. How it works: electrical schematic diagram as shown. 555 IC operates from a single steady state, usually feet and legs are low. When touching something metal sensor chip M, the body's sensing signal through 0.1μF capacitor added to the 555 IC feet, flipped into the temporary brass door knockers state of the circuit, then feet high output directly added doorbell trigger end chip, the chip is triggered and driven by transistor speaker sound. feet while also goes high, the power supply through 100KΩ resistor 4.7μF capacitor charging, when the voltage on the capacitor charge to two-thirds of the supply voltage, the circuit and flip, temporary steady end, pin goes low again level. M once again be touched when the work process again and again. So every touch once M, the doorbell is triggered once. feet 0.01μF capacitor capacitance of interference to prevent false triggering of the doorbell. Component selection and production: doorbell chip used in this circuit, "ding-dong" (AC80F) brass door knockers chip, which is triggered every time, although after pin goes low, it can still send three consecutive "ding-dong" sound. Such as the selection is needed in order to trigger high end has been vocal chip (such as music chip), should be adjusted RC time constant feet to adjust the temporary state of the time, so feet high enough the chip after issuing a complete music becomes low. It should also promote the power transistor chip measure the doorbell base potential, such as static (no sound) is low, then use an NPN transistor as a push tube, the purpose brass door knockers is to prevent static dynamic consumption and extend battery life. Touch the best piece of lead time is too long to use shielded cable and ground the shield. The circuit is made as simple as installing correctly to work properly. The circuit can also be extended to touch switches, touch alarm and other practical circuits. Simple two-tone electronic doorbell Http://www.atchip.com brass door knockers
Works :( ring core companies) principle voice circuit. It consists of a voice sensor, a receiving brass door knockers amplifier, the emitter output, a music integrated circuit, light emitting diodes, speakers, and other components. The external control signal generated by the sound from the electret condenser microphone BM into electrical signals, and is coupled via a capacitor C1 to the voltage amplifying brass door knockers transistor VT1. VT1 output signal via a diode VD2 driver transistor VT2 conduction, so that the power supply voltage is applied to the music integrated circuit IC feet (trigger side), music IC foot music signals emitted by the VT3 amplified to drive the speaker BL loud music sound. And some Meanwhile, brass door knockers light emitting brass door knockers diodes VD3, VD4 the size of the music frequently flashing, like a doll two shining eyes. Regulating circuit resistance potentiometer RP, you can change the BM operating voltage, and thus play a role in changing the voice sensitivity. Capacitor C2 is to prevent false triggering, avoid inrush current impact face settings.
Installation and use: (1) If the family has music doorbell, you do not have to make circuit housing, according to the diagram add control circuit can be. (2) electret microphone BM, mounted outside the frame, highly visible brass door knockers human height brass door knockers may be. For the BM kept clean, available a small cloth cover and marked "Voice" word, you can decoration, but also compelling. Ring core company (3) In order to prevent outside interference caused brass door knockers by misuse of sound work, to adjust RP, so BM with appropriate sensitivity to human mouth off about 30mm electret microphone BM can trigger doorbell appropriate. (4) light-emitting diodes for voice doorbell, only a light tube, which was installed in a conspicuous place outside. When people sound like LED display, then tell outsiders, please rest assured the circuit is working properly. (5) If as children's toys, the choice of a hollow plastic or fluffy toys, will VD3, VD4 into the two eyes, as long as the children's voice, brass door knockers eyes flashing doll will sing, quite fun. (6) when the child does not play, remove the battery. The best selection of 4.7K potentiometer with switch, the switch can be adjusted so that the static power consumption can be saved.
Touch music doorbell KD-482 used in quartz whole point, as in its external plus a few electronic brass door knockers components installed, you can touch-type music composition brass door knockers doorbell. Circuit operating current of 60mA, the quiescent current is almost zero. The circuit is shown below. brass door knockers VT1, VT2 composed touch sensitive switch. When light hand touching the metal sheet A, the injection brass door knockers of the body to the gate of a sensing signal VT1, so that the drain current decreases VT1, the resistance between drain and source is increased, C becomes the high potential point, VT2 conduction, light-emitting diode VD1. At this point D goes low, KD-482 is a low level of the SW end of the oscillation triggered by the VT3 amplified signal to drive the speaker BL sound. Leave the hand A, VT1 of the drain current becomes large, the drain, the gate-source resistance is reduced, C goes low point, VT2 off, VD1 extinguished, D goes high potential point. BL after the broadcast finished a song will automatically stop.
Component selection: field-effect transistor VT1 can also be used in addition to other outside 3DJ6E junction field effect transistor, but requires saturation drain current of less than 1mA. Light-emitting diodes VD1 models brass door knockers can be arbitrarily chosen, for the better, VD1 voltage should choose to work at 2 ~ 2.5V. High luminous brass door knockers efficiency of the arc tube. The area of the metal sheet is about 300mm. Debugging: circuit connected in the figure, the first negative and the SW end of the power of using a metal wire short answer (KD-482 is low trigger), BL released music can be. The control circuit is only a minor adjustment, not before touching A, will play in the DC 1V stalls multimeter to measure b VT2 base and emitter voltage across e should be less than 0.7V, then hand touch A, this time pointer greater than or equal to 0.7V. If not reach this value, may be appropriate to change the resistance R2 or R3, the two resistors best fit adjustment.
The circuit can also be used for security, the contact line VT1 gate installed in the door handle brass door knockers or door locks and other metal parts, when the hand of a thief can contact the police. This circuit can be used to touch upon change children's toys. KD-482 of the E, E 'buzzer connected at both ends of the original ceramic pieces, such as to improve connect two light-emitting diodes VD2, VD3 (as shown below), and light-emitting diodes brass door knockers VD1 mounted in the middle of the forehead just like three eye, not only sets the sound. Light and color in one of the new and interesting, but also would bring children's favorite. Wherein VD1 is used to control the light and dark, VD2. VD3 is with the size of the music rather frequently flashing.
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