Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

current regulator

Status
Not open for further replies.

etgalim

New Member
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?

Thanks for your help...

ET:)
 
Well, I hope I'm getting it right...
Size wise it's 6cm x 7cm or approx. 2.5in x 2.7in (see picture)

I'm not sure about the rating as I took it out of an old dead solar flashlight.

I measured it is bright sun light my meter gave 4.95V, is that any good?

Thank,
ET:confused:
 

Attachments

  • solarPanel.JPG
    solarPanel.JPG
    59.8 KB · Views: 156
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.
 
Thanks...

Do I have to connect it with a battery?
Can't I power the circuit with only the solar panel?

???

Thanks,
Itay
 
Nigel Goodwin said:
Use a battery - it's a very cheap and easy solution, and will allow it to work over a far longer period.

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?

Thanks,
Itay
 
etgalim said:
Hi, and thanks again...
I can't use a battery for this project, it have to be green power only.

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?

Assuming it's an LED display?, it will be taking far too much power for your puny little panel.

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?

Much bigger panel!.
 
Hi Thank a lot for all your help.

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.

Thank again...
Itay
 
get a slightly higher volt panel and use a rechargeable battery as it is quite likely that at times the solar panel will not deliver enough power
 
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.

Good luck.
 
audioguru said:
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.

Good luck.

exaxctly there can be no solar powered device without a backup battery
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top