On Thursday, October 29, 2020 at 9:09:46 AM UTC-5, Peter W. wrote:
However, aren't we wasting energy in a resistor system, rather than
clamping voltage using a (say) a zener or is it the same thing?
The resistor is on play only when the button is being pushed. So the amount of energy 'wasted' is negligible.
The buzzer is rated up to two (2) volts. Which suggests that a 1.5 ohm resistor will accommodate voltage swings from the battery and still protect the buzzer.
Resistors are far less complicated (and thereby more reliable) than a diode, more so if that diode is a zener. The idea is to pass enough current to trip the bell solenoid, yet not damage the buzzer.
I am not so sure batteries, buttons, buzzers and bells understand the concept of "subtle" on the one hand. They may understand "elegant" on the other hand. On the gripping hand, they certainly understand "simple".
I am trying to limit the number of parts involved with the least complicated, most efficient solution that uses what is already in place, and also does not involve brain-damage.

Enjoy!
Peter Wieck
Melrose Park, PA

There you go Petey! See, it's not so hard to be helpful. Just don't inject to much of your inner thoughts when you reply. Give only pertinent information like in this example.