Author Topic: 424 limit switch size  (Read 24 times)

Jawno

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424 limit switch size
« on: July 08, 2019, 02:47:41 PM »
Wondering what size limit switches I should buy. Most of them I've been looking at are rated at 15A, 125-250 volts. That seems way too large to me but I'm just a beginner. Is that a maximum? Any info would be appreciated. I bought some on ebay but when they came they were so small I couldn't find screws to mount them. I'd like something that uses about a 6-32 screw or something similar for mounting. Thanks in advance for any help you can give me.

12strings

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Re: 424 limit switch size
« Reply #1 on: July 11, 2019, 12:28:37 AM »
When connected to PMDX boards, limit/home switches are switching voltages in the 5 to 12VDC range (mostly 5VDC), at current in the maybe 10's of milli-amp range.  So look for the DC rating of the switches, not the AC rating.  But pretty much any switch should do.

I've heard stories about heavy duty switches rated for many amps at AC or DC voltages having reliability issues at low DC voltages and currents because the switches rely on a bit a arcing when the contacts make and break contact in order to clean off any corrosion on the contacts.  And at low currents there isn't any (or enough) arcing to clean to contacts.  I cannot say how "real" this phenomena is, or how big of an effect it is, or how much current rating qualifies as "heavy duty".  Or whether it is just an old machinists tale the guys in suspenders tell the younger folks :) 

Jawno

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Re: 424 limit switch size
« Reply #2 on: July 11, 2019, 10:44:53 AM »
Thank you 12 strings for the reply.