Anonymous asked in Consumer ElectronicsOther - Electronics · 8 years ago

Slow down current drop?

I have a 12 siren that is "supposed" to sound like a tornado siren. However the pitch of the siren drops way too fast when I shut the voltage off going to it. So is there anything I can wire into the circuit that would slowly drop the current after it has been shut off resulting in the siren dropping slower? For example when I shut the switch off the current going to the siren would slowly drop to "0"

2 Answers

  • 8 years ago
    Favorite Answer

    Get an electrolytic capacitor and hook that in parallel with the motor leads.

    You need to experiment with capacitor, or do maths to figure out what capacitor you need.

    Or, if you can, install a flywheel on the motor shaft. It will do the same thing pretty well.

  • Anonymous
    8 years ago

    you could put an electrolytic capaciter of say 300 mico farads across the output stage it would charge up to the supply voltage and slowly discharge when the supply V is turned off. A resister in series would limit the current ergo limit the time it takes to discharge say 10 K Ohm. A thermister may work but you would need to work out the exponential curve for the fall in voltage against the time in seconds to do it accurately what ive said will only work on very low currents being drawn otherwise the cap will discharge to quickly and not work.

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