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BPW34 solar powered led watch

Absolute best watch ever !!!!

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5 years of watch development in one master piece of hardware

https://youtu.be/MieHTr4xJfM

Features:

- BPW34 solar cells ... plastic, small, unbreakable
- ultra High effective step up converter 95% wint minimum 0.4V working voltage
MAX1724 - Thanks for samples form Maxim Integrated
- custom led 4014 display, inspired by https://hackaday.io/whygee https://hackaday.io/project/8693-dypled project
- Supercapacitor capacity gauge

- Supercapacitor can be charged with USB or SUN


Using high voltage 3V 5F supercapacitor from VINATech Co Ltd. ( Thanks for samples ! )
super dimensions 25x8mm

5F is about 5 minutes in highest brightness and 20 minutes in lowest.
In standby abo

At first big thanks Yann Guidon for eagle library for 4014 LED, and great idea with DYP LED project

I understand that this not practical watches, I calling my product
"party watch", not for daily usage but good eye catcher on special
occasions.
Standby time is acceptable, in good condition more than 7 days. If
anybody think that 5 minutes run-time is low? it is abut 300seconds if
you display time
for 3 seconds you can check time 100 times or 350 times in low brightness.

Charging:

Charging is very simple because vinatech scap are 3V, just I use 3V
fixed voltage LDO MCP1700T3002ETT with 10R resistor to limit charging
current + shottky diode
for protection reverse current to LDO .... charging voltage drop to
acceptable 2.95V

Discharging:

Heart is fixed 3V version of MAX1724 extremely low 1.5µA quiescent
supply current Step-Up DC-DC Converter which can work until 0.4V imput
voltage
I can use about 87% of stored energy. In all operation time I have
stable 3.001V for MCU.
I also have on board space for newest MAX17222 ... 300nA Iqc bu I am
unable to solder 6-Pin μDFN
Average consumption is now about 7uA.

MCU:

I am using PICOPOWER Microchip/ATMEL ATMEGA328 stanby consumption with
runing RTC is 0.9uA
Every seconds MCU wake form sleep for add second to counter and flash
led on gauge to show remaining capacity level.
If you press button you can show time, long hold adjust time ...

I am satisfied with results, I have something unique in world ... non
practical but unique ;)

brd - 236.64 kB - 07/20/2017 at 22:32

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sch - 1004.46 kB - 07/20/2017 at 22:32

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Discussions

Jarrett wrote 3 days ago point

How do you find those solar panels? You don't mention how much power they can provide :)

Curious for all sorts of applications

  Are you sure? yes | no

Untitled wrote 07/20/2017 at 21:16 point

Is your PCB open source?  I have a project in mind that would re-use the solar and mpu features of your design.

  Are you sure? yes | no

bobricius wrote 07/20/2017 at 22:33 point

I uploaded board sources in to Files

  Are you sure? yes | no

bobricius wrote 04/21/2017 at 12:04 point

I am using your great library, I am not tested how leds fit (I have no one now), I ordered PCB today I hope that all work as I expect. Of course reflow only, hand soldering is night mare :)

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Yann Guidon / YGDES wrote 04/21/2017 at 11:47 point

So finally you made your own 4014 footprints, but you have to oven-solder them, they are much harder to hand solder this way...

  Are you sure? yes | no

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