After looking for more items around the house which could be charged from the new solar system, we decided to try converting the Logitech Harmony 885 remote control chargers to run from 12 volts.

The Logitech charger runs at 8 volts and uses around 0.4 amps when charging the remote controls.

Using a LM2825N-ADJ Integrated Power Supply 1A DC-DC Converter from National Semiconductor, 2 surface mount resistors and 1 surface mount capacitor we made a small pcb to fit inside the base of the charger which would accept an input voltage from 9V to 40V.

The remote was modified with the addition of a small magnet in the base and in the charger a reed switch was added to allow the remote to automatically turn on the charger when it was placed in the charging cradle. This greatly reduces the energy these chargers normally use as they are designed to run from a plug in mains adaptor which is normally left connected 24/7.

The circuit diagram and pcb design came from the National Semiconductor datasheet on their website (PDF format).More...

After moving my monitors around on the office desk to make way for some new kit, I found that the best place would be if one of the screens was fitted flush against one of the brick walls in the office.

I made this VESA compatible monitor mount from a single piece of aluminum plate after seeing the commercial ones have a much larger standoff than I needed.

Materials Used: 1 x 120 x 120 x 6mm aluminum plate
2 x 4" screws (countersunk)
2 x brown wall plugs

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Putting it all together

Built the first of four panels today and got it installed on the roof. I am still waiting for the 12v 15amp cable roll for the other three panels, which I ordered over a week ago and the supplier isn't answering emails so it looks like I may have lost my money and will have to find it elsewhere.

The photo below shows the thicker tabbing wire used to join the rows of cells

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Soldering Cells

After purchasing a flux pen from Maplin, we started the long job of tinning all the cells, front and back and the fitting the tabbing wire between the cells to join 36 together for each solar panel.

The photo below shows the rolls of tabbing wire, the flux pen and a pack of 50 cells

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