Project help request: Striking a bell manually, alarm clock.

rjenkinsgb said:

I can see a couple of options for the mechanical system:

A solenoid rather than a motor, to operate the mallet:

The striker for a bell or gong usually needs to be "floating" so it bounces away again after a strike, otherwise it mutes the bell.

By varying the pulse duration to a solenoid you could vary the force and so how hard it nudges the striker, then the striker is "thrown" at the bowl by that impulse and can bounce back, with a spring to hold it against the solenoid when idle.

Varying a pulse time or duration is very simple with a microcontroller, as they pretty much all have internal timers.


A motor could do the same thing, but using it as a rotary solenoid in effect, directly swinging the striker & with spring return rather than continuous rotation.

A normal DC motor may not work well for that, as the brushes would be in the same area permanently, but possibly a brushless motor with one winding directly switched & the mallet mount angle set appropriately could work well?

The electronics & clock side is relatively simple, with an appropriate MCU.

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Inquisitive said:

Use an old electro-mechanical door bell striker kit. Like the ones used in houses?

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Inquisitive said:

Use an old electro-mechanical door bell striker kit. Like the ones used in houses?

Click to expand...