Timeline for Digital pins on Arduino function as both positive and negative terminals?
Current License: CC BY-SA 3.0
5 events
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| Sep 28, 2014 at 14:44 | comment | added | Anonymous Penguin | @Jog a piezo will naturally pull more than 40 mA due to ohm's law with its resistance; that's why there is the resistor (that little yellow/tan thing there on the + line). | |
| Sep 28, 2014 at 2:13 | comment | added | Cloud |
@Jog I don't know how a piezo-electric buzzer alters current flow, so let's just assume it's limited to Vcc / R at the most. Forget about the flow of electrons, just accept that the "conventional current" is flowing from the output of GPIO pin 8, through the resistor and buzzer, into the ground, as part of a closed circuit. If you need more current than the Arduino can supply, just have the Arduino connects to the gate of a power MOSFET (ie: hobbytronics.co.uk/image/data/tutorial/arduino-tutorial/…).
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| Sep 27, 2014 at 14:58 | comment | added | Jog | Great, so then in this particular example, the piezo is being powered by the connection to digital pin 8 correct? And we could reliably assume that circuit current is definitely less than 40 mA and probably lower than 20 mA before we measure it? Also, technically speaking, could we say that electrons are in fact flowing from the board's GND to digital pin 8? | |
| Sep 26, 2014 at 22:54 | history | migrated | from electronics.stackexchange.com (revisions) | ||
| Sep 26, 2014 at 22:52 | history | answered | Cloud | CC BY-SA 3.0 |
