... and alarm circuit 4.Infrared scatters on surface of smoke when smoke enters darkroom of detector 5.Photoelectric diode ... purpose of alarming is achieved Smoke alarm specifications: 1.Power supply: 9V DC Block battery/PP3 2.Quiescent current ... fire and security alarm products, including smoke detector, co detector, gas detector, heat detector, water detector, etc. more information, please contact with ...