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.

Fire Fly drawing

Status
Not open for further replies.

spike47

Member
Hi

I am attaching a drawing for a flickering LED solar charged , I am wanting to change the supply voltage to 2.4v ( from 2 x 1.2v Ni-MH ) and using 2 x solar panels from the pound shop ( giving out 5.6v ! ) , driving a flickering LED 1.8v to 2.2v .

What would I have to change to obtain my result ! .

cheers

spike
 

Attachments

  • solar-light-circuit.jpg
    solar-light-circuit.jpg
    49 KB · Views: 130
Here is a link to some designs to step up from 1.5 volts to drive an LED. They should do waht you want with some component value changes.

Les.

Hi

Thanks for your reply , that is no goog to drive a flickering led because it gives a pulse which seems to not drive a flickering led , have tried it , I probably will use just one solar panel .


Spike
 
I do not know if a flickering LED needs a voltage higher than 2V which is a 2-cells almost dead Ni-MH battery. I think a solar panel that produces 5.6V has too much voltage for charging the 2-cells battery to 2.8V.

All my solar garden lights that drive a color changing LED use a 1N5817 Schottky diode feeding the positive pulses to a 0.1uF filter capacitor and the LED. The same color changing LED is used in little lights that are powered from 4.5V button cells battery in series with a 51 ohms resistor. Of course the solar garden lights use a single AAA Ni-MH battery cell that is charged from a series 1N5817 diode from a 2V solar panel. The voltage stepup and switching of the LED on in the dark and off in the daylight are in an IC. Sometimes the IC is in a 4-pins SIP and others are a blob on board.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top