I need to switch an AC signal (0.3 to 1 V) with a 3.3 V MCU and I have no idea on how to proceed. Could someone point me in the right direction or propose a circuit? My last idea is to use a relay, but because of speed and noise I would prefer an IC, not a mechanical solution.
\$\begingroup\$
\$\endgroup\$
3
-
2\$\begingroup\$ Ground referenced? Current? \$\endgroup\$– winnyCommented Sep 14, 2022 at 21:23
-
\$\begingroup\$ I basically have 2 current sensor sct013a, max 10ma that can be connected to my device and I need to switch between this 2 coils as I have a single input. I try with a dg2730 Vishay but no luck \$\endgroup\$– mapomapoCommented Sep 14, 2022 at 22:12
-
1\$\begingroup\$ That answered none of my questions. Please draw a schematic of what you have and how you intend to connect it. \$\endgroup\$– winnyCommented Sep 15, 2022 at 8:05
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
You could use a DPDT analog switch IC or some logic to make one. There are many varieties and sources for them. I do not know your resources so I will not venture a guess. I would switch the signal after the burden resistor because at that point you can keep it below +- 3V3/2 and have your protection where it will cause the least amount of error. The signal from the sensor is an AC signal so you will have to offset it about mid supply with your external circuit. There are a lot of circuits published on the web, a lot of them very similar. Most are for 5V but you can scale the resistance to what you need. I used "arduino 2 sct013a sensor circuit" as my search term. If you use two analog inputs instead of one it will simplify your external circuit and make it more reliable but many microprocessors to not have that many. There are also many inexpensive A/D modules that you could use. If my memory is correct some use the 1-wire protocol. I do not know which MCU you are using there are lots that fit your description and most are not arduino.
