|Restoring Lena-Contact-Sailing Home-Sailing Logs-Uphill photo Tour|
Nice new panel - cost a bomb, well - enough, despite a sale price.
Good quality and not too big for a 30w. Only just after going for this - I found a , rare I might say, unbiased article on the efficiency of solar panels ( produced by some research dept in Ghambia !! ) - their feeling were that, although good quality crystaline ( like mine ) were the most efficient in full sun - the Amorphous types. although bigger for the same wattage, were much less effected by partial shading.
With a bit of sun out the back grden - just about ! I rigged it up to test out just what happened with regard shading.
Firstly, in very weak January sun, 3.00pm - this thing was giving me .75 amps through the multimeter,half its rated full capacity. I was impressed by that. Not so impressed on the shading issue. I tried various shadows with an eye on the ammeter.
A thin long shadow, about half the width of one cell, diagonal or straight, right across, made no major difference. However, once just 'one' of the forty cells was completely shaded, this dropped output drastically - in fact, little difference between one shaded and 'half the panel' shaded.
It would seem in hindsight, I would have been better with amorphous panels for UK type weather. - though this ones great quality - but I think I need to rethink where its going. I had the sprayhood top in mind, but I think it will be best used up on the foredeck - maybe reloacating it in when underway - maybe on the side rail.
Gps Alarm/Juction Box.
Wanting to add the extra alarm for the garmin alarms - this Pietzo buzzer is from Maplins and chucks out 107 db ! - the garmin has a dedicated wire for the purpose. This whole thing has consumed a vast amount of my time, mainly because Garmin said it needed a relay with, - ' max 100mA coil current'. Since I knew nothing about electronics - I had to to a bit of basic self tuition - which has been well worthwhile.
Proud of it now - but I have cursed this little box.
This is the second version - using a little circuit I etched myself. Ten pcb terminals for each individual data wire, plus Garmin 12v+ and 12v+ feed in/ground feed in. I have to put the gromits in the base yet - to correspond with my existing holes. The serial port is on the top right side. The cream connectors are pcb terminal plugs, for the serial port wires, re-set wires and buzzer.
I've used a double coil latching relay - where the primary fires the coil to make Com and NO ( sounds buzzer - and stays there, latched ) then the secondary, fired by the re-set button, flips it back to where it was.
These pietzo buzzers cost next to nothing - a single tone 100 dB is about 1.50 and the above three tone, variable ( three jumper wires ) about 3.50. See here for the circuit layout - and etching the board.