[Boatanchors] Question: Rotary Switch Application

William Morton w_b_morton at hotmail.com
Sun May 26 13:35:17 EDT 2013

Hello All,

I have a project where my goal is to have one rotary switch act as the main power (i.e. standby), heater, and B+ switch.  Position 1 would be off, position 2 would turn on main power, position 3 turns on filament tap, and position 4 would switch the center tap of the rectifier tube.

I have seen separate toggle switches used for each connection in the past but space is limited.  Other applications I have used just have one switch which turns everything on at one time.  I suppose I could do this for my current project but I figured I would try something new this time around.

I happen to have an old rotary switch with 3 poles, adjustable number of positions, and make before break contacts.  The manufacturer is unknown but it looks similar to, say, a Centralab JV 9002, 9005, etc.

Main power is 120 VAC, heaters are 6.3V total current 4A max, and the rectifier is 5V running at 3A.

Is the use of such a switch safe in this application?  My main worry is whether or not I ought to expect arcing issues when the switch is moved from one contact to the next.  I do not think the current levels would be an issue once full contact is made.  I cannot find specs anywhere for the Centralab style of switch so I would like to inquire among the Boatanchor experts.

Thank you very much in advance for your help.

Best Regards,


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