I would say the 2W should be used. I say this because it would be exceptional to spec 2W and there is probably good reason to do so, though I do not know that reason. Often times people with experience with the design reason that a different value will work. Or they find that the component doesn't mechanically fit into the modified design. (I will admit to doing this myself) I suspect that the resistor periodically is dissipating 1W (1W of tolerance). If this is the case, after many cycles, even years, the 1/2W will fail. I will share some experience. I put 2W (12V/0.15A) into a 2W resistor. I went to pick up the board and grabbed it by the resistor and burnt the crap out of my fingers. Overdesigning is good. Cautionary tale: Mrs. Fiorina told the printer mech designers that they make the printers too good and that they should make them cheaper. The company of which she was CEO is not doing so good today.

@NeverDie said in 💬 The Harvester: ultimate power supply for the Raybeacon DK: Edit: This guy found another couple of possibilities as to what the E50D chip might be: https://www.electroschematics.com/pfm-module-circuit-surgery/ I have the same board as this guy. I removed the LED and resistor because they are on the input side, so they are almost useless anyway. For a board such as this, with a promised 0.9v startup voltage on the input side and a promised 5v on the output side, they really should have been attached to the output, not the input, to show roughly when it is that the board is producing useable output. At a 20mv "keep alive" input voltage, the input measures 0.5ma using a uCurrent Gold. That means the keep alive energy is 10 microWatts. Offhand, for the application we've been discussing on this thread, I suspect that number is too high to be practically useful, because at only 20mv input we'd be collecting far less than 0.5ma current from a tiny panel. At least now we know.

It might be possible to power the Arduino off the output pin. Since they are dirt cheap I would just test it. But like the others I would suggest to use the interrupts of pin 2 and 3. For my battery powered 3.3v pro mini I use 3.3v pir sensors without the voltage regulator. The standard 5v pir needs at least 4.5v just to step it down internally to 3.3V. On these I had problems with voltage stability because I stepped it up to 5V. Also the battery lifetime was poor. With the 3.3v pir version this thing runs for months. With the solar panel on top maybe forever.

[image: 1522495412892-img_20180328_162046-resized.jpg] [image: 1522495481563-img_20180328_162106-resized.jpg]

@bisschopsr I now have the schematics posted for all of my boards. I also posted another board for my in-wall scene controller line. Is there any other pics or information that you think might be useful to others for any of these boards?

@ceech I really like this design, however I think it has a problem: According to the datasheet the TPS610986DSET has no feature to disconnect the load at low battery voltages. I think the result will be that e.g. a ESP32 or other power hungry chips will not power up properly. The TPS63031 might therefore be a better fit. btw.: Do you still sell assembled versions of this design? Would you be willing to create a new version with the TPS63031 and probably also with 10 or 20F capacitors or an board to solder your own capacitors. Best regards Tobias

@m26872 said in Encapsulated transformers instead of traditional switching power supplies like Hi-Link: for me the sunny season is too short. I havn't yet tried to use solar batteries in winter so maybe I have the same problems (despite the fact that I'm living 3 degrees south of you), but I have backup solution for very cloudy winter days - regular battery charger.

Hi @koresh - I had a little accident on the AC side :-). I was wondering what values the 2 resistors (TH and SMD) and diode are ? Thanks!

What is the max ampere capacity of 3.3V battery it can charge ? Is there any upper limit like 1000mAh or 3300mAh like that ?

@yury said in 💬 Wall Socket Insertable Node: Looks cool! Do you have experience with capacities switches? I did not play much with them. afraid to use close to AC interference though... You need to use a capacitive IC with active shielding, basically you have an extra electrode around your touch electrode and the touch IC will compare capacitive change of the touch electrode with capacitive change from the shield electrode. If the change is due to electrical interference then both electrodes will be changed in a similar way and the IC will not trigger.

@MiKa which box are you referring to? Generic boxes are available here: https://www.mysensors.org/store/boxes

I like the project. I guess the circuit is not a clone. It costs a lot actually. Is there any other alternatives than cost < 5$ ?

@epierre You can use a Peltier element to power this board. Like this one: http://www.ebay.com/itm/TEC1-12706-12V-60W-Heatsink-Thermoelectric-Cooler-Cooling-Peltier-Plate-Module-/121349774916?hash=item1c41029e44:g:mukAAOSwDNdVrg-U