Check the listing for details. Siren Sound Generator COB. Condition: New. Listed at 0.99 USD. Description: This 18mm x 15mm Chip-on-Board PCB contains a standard alarm siren as used in personal alarms, drivers for piezo horn sirens, cars & toys. It has a wide power supply of between 2V to 5V. (However, one factory does use it with a 9V battery in a personal alarm with no apparent failures.) It has automatic power down & a standby current is less than 2 uA. The chip will tolerate a wide range of component values. A suggested circuit is given below. R1, The oscillator resistor was 47K; R2 3K3 and R3 5K6. With a good choke coil or transformer, and a good piezo resonating chamber sound outputs of over 105dB at 1 meter are obtainable. This is the first time these die form IC's have been generally available to the hobbyist market. Specifications: Siren sound generator PCB size: 18mm x 15mm 2V to 5V operation Standby current of < 2uA Contains a standard siren driver The pinouts are as follows: Pin Position Pin Function -------------- ---------------- 1 VDD Positive 2 to 6V 2 Oscillator Resistor 3 Oscillator Resistor 4 Not connected 5 Push button trigger to Ground 6 Ground 7 Buzzer Output