Dual Tone Air Raid/Security Siren

thingiverse

The main reason sirens get noticed is to alert people in the vicinity of a crime or urgent situation occurring.\nA 5:6 frequency ratio, known as an untempered minor third, enables this siren to stand out more due to two distinct tones sounding simultaneously.\nDesign improvements include reduced complexity by reducing parts for simpler assembly, switching from manual hand cranks to electric motors, and using two tones instead of just one.\nBelow is a list of components required for self-assembly: **Non-Manufactured Parts** * 2 x 3mm dia x 10 mm length fine thread socket cap screws - Total: $0.66 * 2 x 3mm dia split lock washers - Total: $0.50 * Johnson electric motor, 13.6 V, 6290 RPM (part number 9167AJ) - Cost: $3.95 * 12 V, 4 amp AC-DC power supply - Cost: $2.99 * 2mm hex wrench - Cost: $0.30 **Printed Components** * Stator part - Cost: $5 * Rotor part - Cost: $6 Total Construction Cost: $19