Author: Hu Bing Zhao Yang
This recorder can make the reader experience the fun of voice IC. If you are interested, you can use this production to innovate. The following table is the list of this suite component.
First, the working principle of the circuit
This circuit uses an 8 ~ 20S single-segment speech record integrated circuit ISDL820P produced by US ISD. It uses CMOS technology, its basic structure is an oscillator, ahead of a microphone, and automatic gain control. Anti-confusing filter, speaker driver, etc. With high quality, natural voice restore technology, 10,000 voice recording cycles. Automatic power saving, no power consumption information is stored for 100 years, and the operating voltage is 3 to 5V. There are four packages in the package of the integrated circuit. To facilitate the production of success rates, the hard packs of the hard packages are used for the DIPL4 of the 14-pin, and the characters are marked as ISDL820P. Integrated circuit ISDL820P The pin function is: 11 feet are power supply positive (VCC); 8, 14 foot power supply negative (VSS); 1 foot is the recording end (REC), high power is effective, as long as the REC is high when the chip is Start recording; 2 feet is the edge of the PLAYE, when this end is high, the chip starts the play, starting the play, can release Playe; 13 foot is a recording indicator (/ recn), when the recording This end is low, can drive the LED; 4, 5 foot pick microphone input (MIC); 6 foot connections automatic gain control (AGC) end, AGC dynamically adjust the pre-gain to compensate for the wide variation of the microphone input level, Make a lot of volume (from whispering to the hustle), it can remain minimal; 7, 9 foot pick horn output (SP +, SP-), can directly drive 8 Ω or more speakers; 10 foot and oscillator resistance (ROSC This end is connected to the oscillating resistor to VSS.
Serial number
name
Model specifications
Bit number
quantity
1
integrated circuit
ISDL820PY
IC
1
2
microphone
High sensitivity
BM
1
3
led
ψ3, red
led
l
4
Micro Switch
6x6x12 (mm3)
S1, S2
2
5
Resistor
470Ω
R1
1
6
Resistor
1.8k
R3, R4
2
Seduce
Resistor
200k
R2
1
8
Porcelain capacitor
102
C1
1
9
Porcelain capacitor
104
C2, C3, C4
3
10
Electrolytic capacitor
101A,
C5
1
11
speaker
ψ29, 819,
BL
1
12
Circuit board, manual
Be
Be
Each 1
Mean
Fridge front cover, back cover
Be
Be
1 set
14
wire
Speaker 2, positive pole 1, negative electrode 1
Be
4
15
Positive pole piece, negative electrode reed, even
Be
Be
Each 1
16
Self-tapping screws
3x8 (mm square)
Be
2
The following figure is the circuit schematic. The core of this circuit is an integrated circuit ISDL820PY, and there are not many peripheral components. The button switches S1, S2 are picked up, and the microphone is converted to an electrical signal, respectively. R3, R4 is the bias resistance of the microphone. LED is a recorded instruction. Be
Second, the production process of circuitry
1. Full-set-in gas This circuit has 4 fixed resistors, 4 ceramic capacitors, 1 electrolytic capacitor, 1 integrated circuit, microphone, and 1 speaker. Be
2. The resistor in the welded resistor kit uses a common resistor of a 4-color ring.
3. The capacitor in the welding capacitor circuit has a ceramic capacitor and an electrolyte capacitor. Ceramic capacitors have no polarity: the electrolytic capacitor has a polar and long feet is "ten". The short foot is "one", and it is necessary to pay attention to the polarity when the plug is inserted.
4. Welding micro switch welding the micro switch before measuring the switch, when the circuit board is adjusted when inserting. Since the switching handle is relatively long, pay attention to the force to be uniform, prevent damage.
5. The welding integrated circuit integrated circuit is direction. When inserting, the semicircuit slot of the integrated circuit corresponds to the semicircle in the symbol, ensuring the correctness of the polarity.
6. The long feet of the welded light-emitting diode light emitting diode is "+", pay attention to adjust its height while inserting, ensuring that it is good to cooperate with the outer casing, which is a little bit from the hole.
7. The welding microphone microphone is a polarity, which is extremely negative electrode connected to the outer casing. Excessive wires after the welding resistor are connected to the foot. The microphone should be close to the board when inserted on the circuit.
8. Speakers, battery packs and board connecting speakers and battery sheets are first tin before welding, and then connect to the wires, then the wires are connected to the circuit board.
Third, the installation and debugging of the circuit
After the all element is installed, the speaker is placed in the back cover, and the speaker is fixed with a method of hot melt glue or hot melting peripheral plastic. The negative electrode of the inner spring can be properly eliminated to ensure that the battery can be reliably connected. After 2, No. 2, No. 5. This circuit can be successful as long as the welding is correct. The debugging is very simple. Press the "Recording button" does not let go, you can start recording, the total length is 20 seconds, the switch is broken. Take the "playback button" to play. If you don't work properly, please carefully check that the solder joints and the yuan are not wrong, and then work.
Our other product:
