Simple hobby design help

[Steve1977]

Hello All! I just joined and would like some electronic design help. I hope I chose the right thread to put my question. I am somewhat familiar with simple circuits, circuit values, and what most components do. I went to school in the Navy, but that was 20 yrs ago and we never really troubleshot components themselves, or designed our own circuits. That being said, I don't know what info I need to give you, so I will give you what I do know. I need a solar powered, LED, over night use circuit. I am making a Star Wars decoration for the garden and I want the Millennium Falcon lights to go on when the sun goes down. I have round solar cells that are perfect size for the 5 engine spaces on the back and want to stick with them. They put out .5 V each @ 140 mA. Everything else can tailor to them. I would need a total of 7 LEDs, a photocell and rechargeable batteries and whatever resistors/diodes/transistors necessary. Any ideas? Thanks

 

[D.A.(Tony)Stewart]

You must show a datalink to all parts so we can read the specs. PV, LED battery

It won't run for long if the LEDs draw 700 mW ea. I can suggest better LEDs after I read your datasheets.

 

[Steve1977]

Hello D.A., thanks for your reply. I don't have parts any selected except for the solar cells. Here is a link to the solar cells I purchased, if this is what you need. Thanks. https://www.amazon.com/MECCANIXITY-...f_=pd_bap_d_grid_rp_0_1_ec_pd_hp_d_atf_rp_2_i

 

[danadakk]

I would think you would want to drive then in parallel, so if one or more
LEDS/connections craps out does not take down the rest if they were in
series.

If circuit just series solar cells to get V to turn on LEDs then just R's used, then
leds fade on and off at sunrise/sunset. If you want only to come on at a fixed
level then more circuitry needed.

See attached.

 

[dick_freebird]

Your solar cell is your sensor. You want to charge
when "lit" and when charge fails, throw current
onto LEDs instead. That could be something
simple like a reed relay with the LED hanging
off the NC terminal (C=batt, coil from cells to gnd).
Low current coil ought to be tolerable loss (10mA
from ~ 1A cell current?). Blocking Schottky from
cells to battery, and a battery that likes repetitive
overcharging and deep discharge both.