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10 years, 9 months ago.
What can the Digital output pin drive
I want to find out what spec I need to specify to switch a 12v DC device on and off?
I believe the Digital output pin is 3.3v so on is at 3.3v and so switch device input would need to switch at 3.3v?
Cheers Charlie
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2 Answers
10 years, 9 months ago.
The output is 3V3 (or even a bit less). However it is not just the voltage that matters, but also the current you need to supply to the switched device. A standard output pin can source or sink just a very small current (milli Amps). You will definitely need a buffer/driver to control a 12V device. A simple transistor or FET may do depending on the device specs. You may also add a relay for additional current and electrical isolation. Several examples are available on the mbed site (eg http://mbed.org/users/4180_1/notebook/relay-breakout-boards/)
9 years, 4 months ago.
You can use a relay.