I have a very simple power supply circuit, consisting of a 220V:22V transformer, full bridge rectifier (1n4007 diodes) and a smoothing capacitor (electrolytic, 4700uF). The output voltage should sit around 28V. For some reason, the output voltage is often around 0.5V. This is the case even when there is no load attached. I’ve checked all my connections, checked that my diodes are working with a multimeter, checked that the peak forward current doesn’t go over the maximum using LTspice, replaced the capacitor (I replaced the 4700u with two 10000u in series to five around 4700u but this made no difference).
The circuit I’m ultimately trying to build is quite complex but I can’t even get the power supply to give a 28V output. Any ideas why this is the case?