Hi
I have a Solar panel at pick showed 4.98V (+/-) on my meter.
I have a circuit that works with one AAA battery showing 1.54V on my meter.
I need to power the circuit with the solar panel, so I take it that I need a current regulator using a transistor... I think... (???? I'm not sure as my knowledge in electronics is around non-existing)
What I see as a problem is that the solar Panel is at it's pick only in bright sun, what happens if it delivers only, say, 3.9V (cloudy moment)? Will the regulator keeps it at 1.5V anyways? or it will drop below?
Solar panels provide very little current, just connect it via a rectifer diode (to prevent the battery feeding back through the panel) directly to the battery. You might try connecting your meter on the amps range in series with it, to measure the charging current - you'll probably find it's already low enough without any clever electronics.
Hi, and thanks again...
I can't use a battery for this project, it have to be green power only.
And I hooked it up, it shows digits on the display, but as I press a button, it goes dead, as you said, not en ought current.
Just so you'll know, its a simple of-the-shelf egg timer with a digital display and 3 buttons - Min. Sec. and start/stop. and a buzzer
I don't really need the digi-display, you think it will change anything if I'll give it up? will the current be enough in that case? will it run and buzz?
Do you have any idea on how to power this timer with solar power? or how to raise the current for the one I have?
What's not green about a rechargeable battery? - it stores and saves any spare energy, the alternative (wasting it as heat) is far less 'green'.
And I hooked it up, it shows digits on the display, but as I press a button, it goes dead, as you said, not en ought current.
Just so you'll know, its a simple of-the-shelf egg timer with a digital display and 3 buttons - Min. Sec. and start/stop. and a buzzer
I don't really need the digi-display, you think it will change anything if I'll give it up? will the current be enough in that case? will it run and buzz?
I found out the circuit uses 7.5mA at most.
My solar panel is not strong enough to hold it, found on the internet a better solar panel (100mA @ 1.5V) - I'll get it.
Are you going to carry the sun around with you?
What powers the timer when there is no sunshine?
Solar panels deliver their rated current only at noon, on the equator so the sun is directly straight up, only when the panel is aimed directly at the sun, on a bright sunny day.
A window will cut the current in half.
Two hours before noon or after noon also cuts the current in half.
Aiming at where the sun was two hours ago also cuts the current in half.
Clouds cut the current to nearly nothing.
Are you going to carry the sun around with you?
What powers the timer when there is no sunshine?
Solar panels deliver their rated current only at noon, on the equator so the sun is directly straight up, only when the panel is aimed directly at the sun, on a bright sunny day.
A window will cut the current in half.
Two hours before noon or after noon also cuts the current in half.
Aiming at where the sun was two hours ago also cuts the current in half.
Clouds cut the current to nearly nothing.