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Researching New Sequencer Power circuit

A project log for Rittenhouse 520 Sequencer

Replacement sequencer for a Rittenhouse 520 doorbell

michaelMichael 01/21/2021 at 17:420 Comments

Assuming that someone has tried to do something like this before, Google once again comes to the rescue to find a possible solution for my issue.  after some researching I found this very helpful site that gave me a solid background upon which to create my new sequencer:

https://lowpowerlab.com/2015/04/13/doorbell-moteino/

Really easy to follow documentation on how to create a rectifier circuit, as well as a doorbell press detection circuit!  really helpful and simple. So working through what I found I decided that I could probably leverage a lot of what was found in this tutorial, with a few modifications. Because the chime I have requires a constant 16VAC power supply, I already had a power source I could tap into to power the sequencer.    I decided to beef up the rectifier to a full-bridge style chip, I settled on the DF01M for its small packaging and more than adequate output, paired with a 100uF, 50V capacitor to smooth the voltage output.


This was my first foray into some more semi-serious circuit design, as before this it was incredibly simple stuff.  Once I had all that wired up I added a D24V25F5 buck converter from Pololu to drop the voltage to something the ESP32 could handle, and tested the circuit to make sure the output was at the level I expected.  Amazingly it worked!  A few tweaks to the circuit to add an power LED indicator and we had created a stable power source.

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