Wind up radio solar mod
This is my first instructable, so please bare this in mind when building as I may have missed some things.
Also the pictures have been taken with a mobile phone! Sorry!
I was inspired by the solar radio mod by gotwind but I wanted to mod my wind up dynamo powered radio (with light).
Step 1: Parts
I have used 2 old solar garden lights, a soldering iron, solder & the radio.
Once you have got your lights, save the battery from each, remove the solar cell from the top & then remove the LED, 2 large resistors, diode & wires form the circuit board.
The LED & resistors will be used to replace the bulb in the built in flash light section.
Step 2: Bulb Replacement
Remove the case of the radio & extract the bulb (This may be glued in & will need to be eased out).
Notice how in an effort to cut costs, the same coloured wires have been used for both positive & negative connections!
Once the bulb is out, fit the LED in its place (I connected wires to it first to identify the polarity (Flat edge to negative)) along with the resistors & then connect it to the original bulb wires (As I did not have a meter I had to trace the circuit path on the board for + & - connections)
I tested the first part of the mod with standard alkaline batteries to make sure it worked.
Step 3: Solar Panel Connection & Wiring
Connect the red & black wires to the battery terminals, these will be used to attach the solar cell to charge the batteries. Notice the Diode that was removed from the garden light circuit, this is to stop any reverse current leaking back into the solar panels.
The connections are from Solar positive, into the diode with the stripe pointing to Battery positive. i.e the solar call is in parallel with the battery.
This model of radio has a handy label over a cut out hole, ideal to run the wires out of.
The Batteries are fitted (Please DO NOT use alkaline batteries with a solar panel fitted), ready for use / charging.
Finally the solar cells are attached to the connecting wires & the radio can now relax in the sun while charging..
Step 4: Results & Improvements
The 1.2v 600mAh batteries power the radio ok.
The charging times are a bit long, this may be due to voltage loss through the IN5817 Diode that cane with the garden lights.
The LED is much better than the original bulb & the battery lasts much longer as expected.
As I did not touch the dynamo circuit or battery I can always rely on that during the long winter nights.
This mod could be adapted to charge the internal 2.4v 400mAh Ni-cad battery in conjunction with the hand cranked dynamo, just move the wires from the solar cells to this battery (include the diode as well!).