So, I get a call today, the gate at home is not working. Come home, with the light drizzle a portent of things to come. Rain desperately needed to relieve the drought we currently are experiencing, but to do this the rain needs, like the rain in Spain, to fall in the plains, or more appropriately, 200km inland in the catchment areas for the dams that supply water to the metro.
Luckily I have a spare power supply and battery, and after a brief diagnosis, I change the Centurion power supply out for another one that I know works. Freshly charged battery installed along with the power supply, with the drizzle now coming down and threatening to turn into the current light rain. With the Supervisor holding an umbrella over the box, to keep the water out, I put the knitting into the box, slid the cover on and put the screws back, after a brief pause to find the one that dropped into the grass below ( well, it was only 30cm away, so very brief) and a final check on the voltage ( 13.8V and somewhat stable, so good.
Indoors I took the old power supply apart, and the fault is rather obvious. That probably is the reason the battery and power supply is putting out 4.6V. Strange thing the maglock is fine with that, while the remote receivers and relays probably stopped being responsive at around 8V. Maglock is not letting go at 4V, holding the gate firmly shut.
So there are 2 ERA capacitors, 220uF 35V on the secondary side. Well, one is a 220uF 35V capacitor, with quite good ESR, but the other is rather not, it is best described as a 33pF capacitor, which is not really good in a SMPS.
Look in the box of bits, and out pops some slightly used Rubycons, 560uF 35V, out of a scrapped LG inverter aircon that sent off the compressor and the IGBT block in spectacular fashion just out of the 2 year warranty. Lots of good caps on those boards, so I removed a few inot a box. Tested, and both are 600uF and ESR of under 0.1 ohm, so these were the replacements.
In they go, and I do a smoke test. It does keep the smoke inside, so there is nothing else wrong, and also puts out 14.26V, and charges the somewhat flat battery when connected, 12.6v and rising at the moment.
