MultiFA-S RPi zero DC UPS/PSU & MultiFA-L general purpose DC UPS/PSU - Page 1
Forum section: electronics / projects

author: soubitos
author_rank: Frequent Contributor
timestamp: January 18, 2020, 01:17:56 pm
content: After a long time, several prototypes, a few hundred sales of previous variants, i think this is one of the two best forms for this kind of product.Unfortunately, i cannot fully test either of the two versions completely because i am still missing parts for both (expecting replacement for a lost package) .... I couldnt resist though and had to test what i could.Top is MultiFA-SInput 5-40V2.4A maxCharger 1S-1A maxPower Path (DC UPS function)I2C Fuel gauge2 intependent outputsA. 5V1.6A (cont.)B. 3.3V0.8mA maxIt is designed in RPi Zero format and can be used for one as a DC UPS but can also be used on its own for anything else plus, there is a matching logic board (same size/format board with atmega328pb, rtc, its own buck/boost for battery power and available IO and an OLED)Bottom is MultiFA-LInput is 5-28V4A maxCharger 1S Li-Ion/LiPO 2A maxPower pathI2C fuel gaugeOutput here is a simple boost converter in SEPIC configuration so its adjustable from 0.6-24V (5V1A-12V0.25A) which can also be configured as a versatile LED driver for led with forward voltage from as low as a couple volts and up to 24V and with current from 20-500mA (can go higher).This is also in RPi Zero size but not intended to be used with one...It is though possible to use with the same logic board.Test results are frankly as expected, i am very pleased and i hope they sell well too...I am considering the possibility of a crowd-funding for them so i can reduce their cost and make a lot more than i plan but that is consideration.... perhaps if i get enough encouraging comments i do just thatIn this photo, Model S on top is charging while Model L is driving a 500mW led (with 100mA so i can take a photo !!)Further testing gives aprox 77% efficiency driving a 12V6W led (with aprox 2.4W though, didnt want to take it further as its already too difficult load for it!)

author: sokoloff
author_rank: Super Contributor
timestamp: January 18, 2020, 01:30:02 pm
content: Quote from: soubitos on January 18, 2020, 01:17:56 pmI want to be encouraging, so please take this feedback with that in mind.I had to take more than 2 minutes to puzzle out what these things even are. As in "what broad product category is he talking about here?"It seems like it's a "power supply" or "battery charger" or maybe a "portable power supply for Raspberry Pi". (It's kind of all of those things, really, but figure out,from the customers' perspective, what the value proposition is and how to describe and market to them.Making and selling a successful product are two largely distinct activities. It's not enough to have great tech; you also have to be able to explain it to a customer and help them understand how their life is better if they have $20 less and 1 more MultiFA in their life.Best of luck!

author: soubitos
author_rank: Frequent Contributor
timestamp: January 18, 2020, 01:36:21 pm
content: Thank you for taking the time and i really appreciate your comment...Well, i am planning a much better presentation and especially model L will be presented in action so people can understand what it is and what it can do, its not so easy sometimes, esp if english is not your native language

author: soubitos
author_rank: Frequent Contributor
timestamp: January 19, 2020, 09:48:53 am
content: dont see much interest......