I've got the power!

In messing with bits for a door entry / alarm system, everything is currently powered with 12V. However, these little ESP8266 processors are 3.3V.

Obviously I need a regulator, and as I am making these up using a milling machine, a small self contained module I can solder on to a PCB as a single component is the obvious choice. Back to Amazon, and I find something simple and cheap :-

It has three 0.1" pitch leads, and so easily mounts on the PCB. It has an offset with a header as it has components both sides. Works well though.

However, I noticed it gets a bit warm. Not really a huge surprise, but even when just powering from 5V in my Galaxy keypad design it still is a touch warm.

So I did a bit more research and found these tiny switch mode supplies, Pololu D24V5F3. A few pounds more expensive, also available from Amazon, but really really nice:-

  • Still a very small design 0.4" by 0.5" (yes, bloody inches!).
  • Components only one side, so can mount flush to my PCB making easy for something like an ESP-01 to fly over it and save more space.
  • Cool. I mean really cool. They say 2mA, and given that my ESP-12F plus RC522, running off 12V on one of these is 30mA total, I am impressed. I was seeing 140mA previously.
  • It also has a shutdown input - which I suspect I could use with a button on a battery powered device so you can power up and then have s/w power down. I wonder if I can even do something clever with sleep mode on an ESP8266 shutting down its own power while it sleeps - may need a capacitor somewhere in that :-)
  • Will accept from around 3.5V up to 36V as input!
  • They do other voltages, and current ratings as well, and step-up regulators.
Actually a D24V6F3, the D24V5F3 are on order
Basically, I am working through the total maze of too much information trying to weed out the good from the bad and work out what sort of components are good. I think this comes in to the "good" category for voltage regulator.

1 comment:

  1. These mini buck regulators are amazing. I have the single-chip version replacing the 5V linear regulator in my ZX81 and Spectrum --- they run so cool that I can dispense with the entire heat sink.

    That one was expensive, but I also have a box full of the adjustable ones from banggood; twiddle a pot on top and they'll generate a stable voltage from anything from 2V to about 30V. They cost practically nothing, and they're ideal for powering random low-power electronics as you can plug them into pretty much any source and it'll work. The ones I have are limited to about 100mA, though; above that they start to flake out.


Comments are moderated purely to filter out obvious spam, but it means they may not show immediately.

Shelly Plus i4DC GPIO

As previously posted , I am quite impressed with Shelly stuff anyway, but the new "Plus" range has allowed some interesting develo...