On Sat, 23 Jan 2016, tony duell wrote:
Incidentally, some machines have those sealed metal cans containing filter capacitors, inductors and sometimes discharge resistors [2]. Has anyone ever had the capacitors in one of those fail?
Actually, yes. I had one fail in one of my scopes. I don't recall the brand/series right now, but it is apparently a known issue with that particular series of filters. I still need to replace the same filters in the other scopes since they will most like do the same thing eventually.
[2] I wish the manufacturers would print a schematic on the can, or at least in an available data sheet. If I measure a 1M leak to earth from the live pin (say), I want to know if it's a deliberate discharging resistor or a leaking capacitor.
Most of the IEC320 input filters I've used have a schematic on the can or in the datasheet. They are usually also careful to denote the medical-rated filters which lack the Y-type safety capacitors between the two supply terminals and ground.
