Teach you to make a “smiley face” small pendant

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“Smile” is a classic cartoon that everyone knows and loves with the “face” picture, which represents the friendliness of affinity and reflects the positive energy of society. She always reminds everyone: please keep smiling! No matter what life is, You have to smile every day, keep positive energy every day, just be happy, life is actually not so bad …


Do a high -sensitivity “smiley face” small pendant (see the question map), hang it near the room audio or where people often speak, then as the music or voice sounds, inlaid in the “smiley face” eyes position position. The glow diode will shine with the rhythm of music or sound, allowing you to enjoy the perfect combination of music, flashing and “smiley face”, which can add a lot to the room.

The entire production cost is less than 5 yuan, and it is easy to make. Mind is not as good as action, make it to make with me!

Understand the principle of working

The circuit of the small pendant of the “smiley face” is shown in Figure 1-1. It is actually a sound control flash circuit composed of ordinary separate components. Four parts.

Figure 1-1 “Smile Face Welcome” small pendant circuit diagram

The pick-up circuit is the “sound-electric” converter in the Sports Mes. B. R1 is its power supply bias resistor (also known as the load resistor). When the microphone B picks up the surrounding sound wave signal, it is converted to the corresponding electrical signal. The electrical signal is sent to the base of the crystal triode VT1 via the capacitance C. VT1 and VT2 form a two -stage direct -coupled amplifier circuit. Although the circuit is simple, the design is clever. By selecting the appropriate R2 and R3 resistance values, when the silent wave signal is used, VT1 is just in the leading state. Essence When the microphone B picks up the surrounding sound wave signal and has audio signals injecting the base pole of VT1, the negative half a week of the audio signal will exit the VT1 to the saturated area. , VD2 lights up; when the audio signal is weak or disappeared, it is not enough to exit the VT1 to exit the saturated area, and VD1 and VD2 will return to extinguish. With the changes and rhythm of the surrounding music (or speaking), the light -emitting diode VD1 and VD2 will make synchronous flash.

In the circuit, the resistor R1 determines the static operating voltage and current of the static operator B in the body microphone B. Properly increase its resistance value to increase the acoustic sensitivity of the circuit. R2 is the bias resistor of the crystal transistor VT1. The R3 is both the load resistor of the VT1 and the bias resistor of the VT2. The size of R1 and R3 resistance directly determines the size of the circuit’s static power consumption. Here is intended to choose the resistance value larger to reduce the static current of the entire machine (actual measurement ≤0.46m A), which is relative to the service life of the battery G.

Prepare components

This production shared 12 electronic components. Figure 1-2 shows the physical appearance map of all electronic components. The procurement list is shown in Table 1.


Figure 1-2


Table 1 component list

VT1 and VT2 use 9014 with a large current seductive coefficient β (the maximum allowable current ICM = 0.1A, the maximum allowable power consumption PCM = 310m W), or a 3DG8 silicon NPN small -power crystal triode, which requires β ≥200.


VD1 and VD2 are best to choose φ5mm red light -emitting diode, which requires the two tubes to maintain the consistency as much as possible (the manufacturer should be selected in the same batch and the same specifications) to avoid the phenomenon of two tubes “bright and darker” during light. For example, when using white or Blu -ray glowing diodes, the power supply voltage needs to be increased to 4.5V. Generally, readers do not recommend it.

B selects the CM-18W type (φ10mm × 6.5mm) high sensitivity to the polar body microphone. Its shape and pin recognition are shown in Figure 1-3 (a). The sensitivity of CM-18W is divided into five gears, which are represented by color points: red is -66DB, small yellow is -62DB, rhubarb is -58dB, blue is -54dB, and white> -52DB. Blue or white dot products should be selected in this production to obtain high sensitivity.

B can also be replaced directly with other small-sized small body microphone (such as CRZ2-113F). When selecting the polar microphone, the pointer-type multimeter can be placed in “ω × 1k” or “ω × 100” gear, and according to Figure 1-3 (b), the ground end of the polar microphone is connected to the polar microphone ( Like the shell), the output end D of the black table is connected to the polar microphone. At this time, the multimeter pointer refers to a certain scale, and then use the mouth to blow the body microphone with the mouth. The multimeter should have a large swing. And the larger the multimeter pointer swing range, the higher the sensitivity of the polar microphone. If there is no response, it means that the measurement of the polar microphone has been damaged.

R1 ~ R3 uses RTX-1/8W carbon film resistor. C uses a CD11-16V electrolytic capacitor. G is made in series (plastic battery rack) with two sections 5 of the 5th section 5, and the voltage is 3V.

Figure 1-3 Identification and test of the microphone in the polar body

Start making

The production of the small pendant of the “smiley face” can be divided into four steps: “Smile” shell, welding circuit, power -powered debugging and completion of the assembly. The following is introduced according to the production steps and processes.

The first step, ingenious shell


A “smiley face” shell with an exquisite appearance and proportional proportion is the key to the entire work achieved satisfactory results. The author pastes the cardboard with “smiley” on the plastic wide -mouth bottle cap with a suitable size, and is equipped with the appropriate hanging line and threading, that is, obtain a simple and beautiful shell -the bottle cap is used to install all circuits Essence The specific production process is shown in Figure 1-4.

First of all, according to Figure 1-4 (a), take a plastic bottle cap of about a φ85mm × 15mm. Generally, the empty-mouth plastic bottle or glass bottle that is installed in the home. It’s easy to meet the needs.

Then, take a piece of yellow cardboard (or copy paper), and according to Figure 1-4 (b), the wide-mouth bottle of the bottle cap is buckled on the yellow cardboard (note: under the card paper must be matched with defense The hard cardboard of scratching the desktop, etc., used in the figure is a special PVC-made cutting pad), and use the sharp blade of the knife to cut a circle along the side of the wide mouth bottle, and cut out the yellow circle shown in Figure 1-4 (c) shown in Figure 1-4 (C). Paper. Then according to Figure 1-4 (d), with the help of the oval template ruler and ordinary pencils, “smiley faces” lines on yellow round paper, as shown in Figure 1-4 (e), Use black brushes (or brush) to describe your eyes and mouth. According to Figure 1-4 (F), the two-sided non-dry tape paper is pasted on the back of the yellow round paper on the back of the “smiley face”, and according to Figure 1-4 (g) Cut the excess parts around the round paper. According to Figure 1-4 (h), tore off the protective wax light paper on the double-sided non-dry tape paper, and according to the shown in Figure 1-4 (i), the “smiley” round paper is pasted in the place Selected plastic bottle cap. It should be explained here: If the yellow cardboard is used to use yellow non -dry glue stickers, you can save the steps of pasteting double -sided non -dry tape paper, and the paste effect is more ideal. If the reader can buy a “smiley face” sticker with a suitable size, or use a color inkjet printer to print the “smiley face” picture downloaded online on the photo paper, the effect is better!


Figure 1-4 ingenious “Smile Face” shell

Figure 1-4 ingenious “Smile Face” shell (continued)

Next, according to Figure 1-4 (j), on the bottle cap with a “smiley face”, a small round hole of φ5mm was performed with a round pointed e-iron in the middle of the two “eyes”. , Used to install the emitting diode VD1 and VD2. According to Figure 1-4 (K), a small hole is tied with an awl on the upper and lower side of the bottle cap. According to Figure 1-4 (L), the small round hole of φ10mm is scalded with any side of the lower hole on any side of the lower hole for installation of Zhizi microphone B. The hot holes can be repaired according to the edge of the hole in Figure 1-4 (m) in Figure 1-4 (m). If necessary, you can also use a semi-circular small knife to grind.

Finally, according to Figure 1-4 (n), in the small holes on the upper side of the “Smile” shell, wearing a double-rooted red line with a double-rooted and length of about 12cm from the inside, and on the line head in the shell Put on “dead knots” to prevent “hanging” from falling off. According to Figure 1-4 (O), in the small holes under the “Smile” case, the red thread ears are worn from the outside, and the “dead ears” are used to prevent the “thread ears” from falling off. Essence In this way, a lively and cute “smiley face” shell is ready.


The second step, the welding circuit

The single-hole “hole board” with a size of about 24 mm × 22mm is cut, and welded according to the circuit board wiring diagram given in Figure 1-5 (note: the welding surface faces the reader, the component is on the back of the board). The advantage of using the “hole board” is that the material is simple, the cost is low, and the use is convenient to achieve half the effort. The welding physical objects are shown in Figure 1-6.

Figure 1-5 “Cave Board” wiring diagram


Figure 1-6 Welded circuit

When welding, it should be used to make full use of component pins to connect to the wire, which is required to be bright and neat, and the occurrence of welding, virtual welding, and fake welding should be required to avoid the occurrence of wrong welding, virtual welding, and fake welding. Welding the two fine wires of the 11cm long and black wires of the Extra Skin B is welded on the “Cave Plate”. The red lead is the output terminal of the Sports Mesh B D, the black lead is the grounding end; The two fine wires (red are positive and black are negative poles), which are correctly welded on the “cave plate” and requires the length of the lead to be ≥8cm; The 5mm long pin is kept on the front of the circuit board, so that when the assembly is bended 180 °, it is directly inserted into the “eye hole” opened by the shell; the capacitor C should also retain a 5mm long pin.

Step 3, power -on debugging

In the circuit diagram of Figure 1-1 and the wiring diagram of Figure 1-5, check the welded circuit repeatedly. After confirming the correctness, you can install two in the plastic battery frame according to Figure 1-7 (a). The festival 5 dry battery is conducted. Under normal circumstances, as shown in Figure 1-7 (b), speaking at the Zizi Merchant B with your mouth at a distance of 0.5 to 1m, the light-emitting diode VD1 and VD2 should be shiny with the sound, and with the changes in the sound of the sound, The brightness of the light also changed, indicating that the circuit works well.


If you speak to the Extreme Merchant B, there is no response to the light emitting diode VD1 and VD2, indicating that it is either the battery G is not normal, or the positive and negative polarity of the two emitting diode is all overlap. It is very bright, and most of the crystal triode VT1 or VT2 is wrong. Check it carefully and remove it to make the circuit work normally.


If you need to shout loudly, the light -emitting diode will shine, indicating that the sound control sensitivity of the circuit is too low. This may be that the crystal triode VT1 is in a deep saturation state, and the large audio signal input VT1 base is required to exit it. The solution is shown in Figure 1-7 (C). The resistance value of the resistor R3 can be appropriately reduced or the resistance value of the resistor R2 can be increased, so that VT1 is just entering the saturation state. In addition, when the lead of the Sports microphone B is overwhelmed, the brightness of the diode in the speech is extremely weak, and it should be checked and corrected.

If the sound control of the circuit is too high, a small sound will flash the light-emitting diode, and even the light-emitting diode is in a state of light when silent, indicating that the VT1 does not enter a complete guide state. At this time, it can be according to Figure 1-7 (d). It is shown that the resistance value of the resistor R3 appropriately increases the resistance value of the resistor R2, so that the VT1 can enter the leading state, and the VT1 can also be replaced with a tube with a higher volume β value.

When debugging, the resistance value of the resistor R2 can generally be changed within the range of 510kΩ to 3MΩ; the resistance value of the resistor R3 can be changed within a range of 3 to 20kΩ. However, the resistance value of R3 should not be too small, otherwise the static power consumption of the circuit will increase significantly.

Figure 1-7 Circuit debugging method

Step 4, complete assembly

The debugging circuit should be assembled after taking out the dry battery G from the plastic battery frame.

First of all, according to Figure 1-8 (a), with the help of sharp mouth pliers or tweezers, the two luminous diode VD1 and VD2 that have been welded on the “hole board” are welded on the front of the circuit board. °; then according to Figure 1-8 (b), pinch the circuit board with one hand, pinch the glow diode VD1 or VD2 tube cap, and carefully discount the two emitting diode 90 ° in order to be like Figure 1 in Figure 1 -8 (C), as shown in, can insert the circuit board into the “eye hole” on the back of the “smiley face”.

Then, according to Figure 1-8 (d), insert the φ10mm round hole from the side of the “Smile” housing from the inside out of the “Smile Face” shell.

Finally, according to Figure 1-8 (E), the location of the 3V plastic battery frame and the leading position is set, and according to the simple method of the hot-melt rubber sticks as shown in Figure 1-8 (f), it will be used. The light emitting diode VD1 and VD2, Zhizhi microphone B, battery holder, and lead are selected in the plastic shell with hot melting glue in the “smiley face”. In addition, refer to the method shown in Figure 1-8 (b), and the electrolytic capacitor C on the circuit board is bent from the original upright state to the horizontal state shown in Figure 1-8 (g) to ensure that all components are super high in height. But plastic shell height. OK! A simple and beautiful, different “smiley face” small pendant is made, and you can formally put it into use!

Figure 1-8 “Smile Face” assembly flowchart

Figure 1-8 “Smile” assembly flowchart (continued)


Invest in actual use

The successful “smiley face” work can be hung in the room to receive the sound or the sound of good voice and the ideal decorative effect. Figure 1-9 gives several typical application examples for readers’ reference. Note: When “smiling faces” are directly hung on the TV, speakers, etc., it is best to use a beautiful suction cup plastic or silicone as shown in Figure 1-9 (a) or Figure 1-9 (C). Small hook, this is flexible and not destroyed the shell of the appliance.


Figure 1-4 ingenious “Smile Face” shell (continued)


Because the “smiley” circuit is in a quiet environment, the light -emitting diode VD1 and VD2 are not emitted, and the static power consumption of the entire circuit consumes a small power and the actual static current is ≤0.46mA.Under normal circumstances, the “smiley face” can be used for 1 to 2 months for each ordinary new dry battery.If you do not use the “Smile” pendant for a long time, just remove the dry battery G from the battery frame on the back.

Figure 1-9 several application scenarios

(Circle cards have been added here, please check today’s headline client)

Author: ArticleManager