• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

UL - triode switch

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
A lot of SE pentode amps have a switch to change from triode to ultralinear taps on the output transformer. In principle, most switches can't handle the voltage from plate to ground which can often be around 450 V quiescent, plus the AC swing which could easily give 700 V. Do people worry about this, or have bad experiences with terminal to ground shorts? I couldn't find real specs for the max. breakdown voltages for common AC line switches, but even 220 VAC switches wouldn't need to handle more than about 300V max. Are there common switches designed for this that won't cost a load of money? I don't really want to get a lethal shock off my UL-anode toggle switch.

Eric
 
An inductive DC load is about the worst case scenario for a switch (does not cross through 0 like AC, arcs stay lit easier). Most switches are rated for AC, not DC, or are rated lower for DC. The rating has more to do with the contacts and their breaking and making than the insulation. I would be wary of switching hot, do not do it if its break before make. Doing so may be hard not just on the switch, but the OPT.

Example of a relatively cheap 480VAC switch. Break before make.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.