■ Function Description
1. Working voltage: 1.35V – 5.00VDC
2. Sound: Down Bi Bi Sudden sound
3. BZ1, BZ2: inverted click output : a. BZ1 -- duty = 1/3 : b. BZ2 -- duty = 1/6
4. KEY : LEVEL HOLD mode, connected to VDD
5. Rosc : External resistance adjustment speed
6. LAMP: positive output - connected to NPN 8050 transistor, lit with Bi Bi
7. LED: Negative output - Connect to NPN 8050 transistor, light off with Bi Bi