Power switch options

[pitchinwedge]

Your new diagram looks correct, another way to correctly install a snubber is in parallel with your load (the power transformer). However, your calculated values are off. A common combination is a .1uF X2 safety capacitor in series with a 4.7R 1W resistor.

Most importantly the capacitor needs to be at least X2 rated, this will help avoid catastrophic failure of the capacitor. Older amps commonly used 2500V ceramic capacitors and they were known to occasionally blow apart.

Gads, those formulas must be way off! Anyways, I found some parts based on your comment. Will these work?

0.1µF ±20% 400VAC Ceramic Capacitor Y5V (F) Radial, Disc
4.7 Ohms ±5% 1W Through Hole Resistor Axial Flame Proof, Fusible, Safety Wirewound

Thanks for the help!

 

[akimmet]

You neglected to mention if the capacitor you chose is safety rated. Make sure the capacitor you chose is X1 or X2 rated! Your snubber needs to absorb voltage transients in excess of 1000V, a standard 400V capacitor is likely to fail.

In .1uF, X2 film capacitors are usually much less expensive than X2 Ceramic capacitors.

 

[pitchinwedge]

Yes, the spec sheets rated X2 for 1500v. Thanks again, will try to install it next week.

 

[elobilo]

A common combination is a .1uF X2 safety capacitor in series with a 4.7R 1W resistor.

Would these values also be OK for 230v supplies?