On/Off Rocker Switch Query

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Joined: Fri Sep 30, 2016 2:52 pm

On/Off Rocker Switch Query

Post by scsibear » Fri Sep 30, 2016 3:12 pm

Hi everyone
I'm stuck on my first project and was hoping someone could advise me on some understanding of this switch issue i have.

I bought a vintage parametric equalizer from the US, naturally it's a 115v unit which i am converting to UK 240v, i have the new torroidial tranny and everything is as it should be.
My problem is the actual on/off rocker switch (2 pins) What i want to know is can i use the switch that is already in the unit ? will it handle the 240v or is it specifically made for 115v only.
The switch is a Swan series 40, there is no serial number on the switch at all (made in the 70's) all that's on it is the swan name and series 40 also the confusing part there's a 12v stamp on it !

My confusion is how can it be 12v but take 115v mains ? am i missing something important here ?
can i use the same switch to power on/off this unit at 240v or should i get one specified UK 240v instead

any advice or pointers to help me understand this is much appreciated


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Joined: Sun Sep 06, 2015 11:34 am

Re: On/Off Rocker Switch Query

Post by magpie » Thu Oct 06, 2016 9:37 pm

The switch manufacturers would have given data on their products, but given the age of what you have I would guess they are no longer available. The low voltage is only an indicator of what it will do but if you had the whole information, it should also show it can be used on 115v and 240v ac. The current it would carry will depend on the load ie...inductive or resistive. As you cannot be sure what the condition of the contacts are, I would suggest that you could alter the wiring,and use the switch to close a small 240v relay to carry the load.To make sure I would I would test it by putting 240v on the switch with a lamp as load, and small fuse for protection.If you have access to a Variac transformer then you could wind up the voltage from zero.

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Re: On/Off Rocker Switch Query

Post by David » Fri Oct 07, 2016 9:28 pm

Assuming the switch switches the mains input, I would certainly replace it with one rated for 240v. The amperage is dependant on the load (as magpie says) - can you post a photograph of the existing switch in situ? Is there a notice on the unit which shows its consumption in watts? If so, divide the watts by 240 to give you the working current. Increase the figure by 2 or 3 times for a safety margin. If the equaliser is a small(ish) domestic type unit, I would expect a rating of some 2 amps and upwards would be OK. Suitable switches should be very easy to find - try RS or Maplins.

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Re: On/Off Rocker Switch Query

Post by Elechobby » Sun Oct 30, 2016 1:53 pm

Hi, scsibear
The company sell switches, and they probably will help your question of you call them. 'RMCybernetics', I bought from them through ebay a while ago, good to use in UK. BTW, they are in UK so quite fast shipping to me

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