Could someone please indicate what the significance is of a 9V AC - AC adapter other than it’s low voltage and therefore relatively safe for numpties like me.
The only adaptor I have close to a 9V AC - AC is an Ikea transfomer for one of their small (20W) light fittings. The adaptor is marked up as Primary 220 - 240V ~ 50Hz and 0.1A with secondary of 11.5V ~ 10 to 20W.
At this stage I’m just looking to obtain AC voltage and will move on to current later so I worked through the “9V AC - AC adaptor” tutorial. I hacked the Arduino library and sketch just to provide voltage and it came out pretty much spot on except it was double the actual voltage. So a further hack to halve the values and the figures look ok.
Is this a pure fluke and it’s simply not possible to get the correct figures with the “Ikea” adaptor I have?
I only have 0.1 μF and 100 μF caps which are both 10 times too big / small compared with the 1 μF to 10 μF range recommended. I plumped for 0.1 μF as it’s says the cap size is not critical but open to suggestions. I have 5 off 100 μF so I guess I could get that down to 20 μF in series if it’s important until I pick up some 10 μF caps.