Realize voice recording by a simple operation; can enhance the learners' interest and practical ability; Voltage: DC 4~5V; ISD1820 11 feet is positive power supply (VCC); 8, 14 feet to the negative power supply (GND); 1 foot is the recording end (REC), high active, pressthe button AN1 chip AN2 start playback, start playback, the button can be released; 13 feet is the end of the voice instructions (RECLED), w hen in recording status indicator light D2, R1 is limiting resistance; 4, 5 feet by C1, C2 external microphone inputs (MICI); 6 feet to the AGC terminal, then the capacitor C4; 7, 9 feet to the speaker output (SP +, SP -), can directly drive 8ohm speaker above; 10 feet to oscillation resistor R2, changing the value of R2 can change the recording time and quality, the shorter the time entered the sound quality, the longer the sound input worse; Vibration resistance optional (82K 120K 200K), corresponding to the recording time are 8S 12S 20S. R3, R4, R5 is a bias resistor, C3 for the filter capacitor; CZ4 for the external port, the device can be controlled by the port of the module recorder. D1 to supply anti-reverse diode.