Re: Plug in surge question
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Older HP equipment does not power up anything until the power switch is turned ON, with the exception of things like frequency standards and counters, which may apply power to the crystal oven and in some units the oscillator. Any line filters before the switch will of course be under power any time the plug is in a live power line socket. These line filters draw a tiny amount from the line (ignoring capacitor failures, which draw more than a ¡°tiny amount¡±).? In fact, a couple of dozen such instruments, connected via power strips to a single outlet, can cause a problem: even though you may use no more that one or two instruments at a time, thus not exceeding current ratings, the line filters all combined can draw enough to pop a GFCI breaker.? The surge you are speaking of can occur as large filter caps charge up. Vacuum tube instruments can also see surges as filaments warm up. HP designs are all rated to withstand such surges when new but a fifty-yo instrument may have aged components in need of replacement. It¡¯s possible to install surge protectors, which limit current in the first few seconds after turn-on. I¡¯ve done that for a couple of large vacuum tube instruments, to perhaps extend the life of the vacuum tube filaments. On Sat, Jun 5, 2021 at 10:24 AM DW <wilson2115@...> wrote: I have understood that initially when you plug in a instrument, depending on the kind instrument there might be a brief power surge. My understanding is the rectifier capacitors are being charged as one example I can think of. --
Jeremy Nichols 6. |
Jeremy Nichols