UM3561 Tone Adjustment

[Suraj143]

Guys I want to make a fire alarm sound.The below circuit I made & it works.

The only problem is its tone is in high pitch,I need a more weight tone as fire siren modules has.

How to get more low frequency tone?

 

[ronsimpson]

How to get more low frequency tone?

If you want a lower frequency try replacing the 200k ohm resistor with a higher value. Example a 400k resistor will probably drop the time by one octave. A 330k is a good place to start.