Read 24 Vac signal with a Raspberry Pi
Electrical Engineering Asked by Riccardo Minati on July 25, 2020
I want to read a 24 Vac signal coming from my old automatic gate with my Raspberry Pi. The signal tells me if the gate is OPEN->24 Vac or CLOSED->0 Vac. Raspberry Pi input are 3.3 Vdc tollerant. My first idea was to use a rectifier to get a DC signal and then use a voltage dividers to get the 3.3 Vdc. The second one was to use a octocoupler to achieve the same results. Has anyone any suggestion on what type of such devices should I use to achieve my goal?
Best regards
Ric
One Answer
Instead of using a slightly larger number of inexpensive multiple-sourced parts, you could consider using a part designed for this kind of application, the TI ISO1211.
See Figure 3. I think values of Rsense = 560 ohms, Rthr = Rshunt = 1K and C = 100uF/50V would work, but check that yourself. It will run off the 3.3V Pi power supply.
You might want to use a bridge rated at a bit higher voltage.
Answered by Spehro Pefhany on July 25, 2020
Add your own answers!
Ask a Question
Get help from others!
Recent Answers
- Joshua Engel on Why fry rice before boiling?
- Jon Church on Why fry rice before boiling?
- Peter Machado on Why fry rice before boiling?
- haakon.io on Why fry rice before boiling?
- Lex on Does Google Analytics track 404 page responses as valid page views?
Recent Questions
- How can I transform graph image into a tikzpicture LaTeX code?
- How Do I Get The Ifruit App Off Of Gta 5 / Grand Theft Auto 5
- Iv’e designed a space elevator using a series of lasers. do you know anybody i could submit the designs too that could manufacture the concept and put it to use
- Need help finding a book. Female OP protagonist, magic
- Why is the WWF pending games (“Your turn”) area replaced w/ a column of “Bonus & Reward”gift boxes?