Hello
I would like to know how did the circuit designer of the circuit in the image calculated resistor R100 value.
I have tried to figure it out by myself but I'm not sure about it. I would like to know if my calculations are right.
My guess is that the 100ohm resistor is to limit the current to ~20mA.
buzzer's datasheet http://www.puiaudio.com/pdf/SMT-0540-S-R.pdf​
The buzzer's datasheet says that Vp-p = 3V, Imax = 100mA.
To use Ohm's law to calculate R100 we have to 'translate' Vp-p to Vrms (kind of avg voltage) so,
Vrms = 0.35355 * Vp-p = 1.06V.
Then by Ohm's law:
R100 = (3.3 - 1.06) / 0.020 = ~100Ohm.
My calculations are right?
Thank you!
I would like to know how did the circuit designer of the circuit in the image calculated resistor R100 value.
I have tried to figure it out by myself but I'm not sure about it. I would like to know if my calculations are right.
My guess is that the 100ohm resistor is to limit the current to ~20mA.
buzzer's datasheet http://www.puiaudio.com/pdf/SMT-0540-S-R.pdf​
The buzzer's datasheet says that Vp-p = 3V, Imax = 100mA.
To use Ohm's law to calculate R100 we have to 'translate' Vp-p to Vrms (kind of avg voltage) so,
Vrms = 0.35355 * Vp-p = 1.06V.
Then by Ohm's law:
R100 = (3.3 - 1.06) / 0.020 = ~100Ohm.
My calculations are right?
Thank you!
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