capacitors Preventing sparking

im trying to build a sollenoid motor like this one

http://www.youtube.com/watch?v=e3tcdiO2HCc&feature=channel

and i need to no how to prevent sparking on the switch so that im not constantly having to replace it. ive heard somewhere that a capacitor will prevent a spark on the switch but will it? and how big of one will i need. thanks

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Æ6 years ago
Yes, you can add a capacitor across contact terminals, it's called a snubber. Same as the "condenser" on a an old fashioned car distributor with breaker points. Absorbs the arc/spark. A MOV can be used too, because it looks (measures) like a capacitor. You have to determine the amount of capacitance empirically. Add small amounts, start with .1uF and add additional amounts until the spark has subsided.
aeronut017 years ago
Has anyone mentioned trying a varistor?  The website   www.phonda.com.tw/varistor.htm clearly describes its function.  Basically, its a resistor that varies from almost non-conductive to very conductive depending on the voltage fed into it.  You wire it in parallel to the switch and the next time a spark heads to the switch, the varistor should absorb the spike in electricity.  BTW, a varistor is also called a "metal oxide varistor" or "MOV".  If that doesn't work, try a ZNR (Zinc Resistor), but the MOV should work just fine.
lemonie8 years ago
You could use a solid-state switch, something with silicon in it? L
Well, the semiconductor will burn out from the voltage spikes. it will still require some form of protection.
110100101108 years ago
its parallel to the switch. i guess 0.1 uF 600 V is about ok but not sure
. The condenser from an old (points) automotive ignition should work. . Or get a switch with a higher interrupting current (AIC) rating.
budsiskos (author)  NachoMahma8 years ago
i was planing on making my own switch out of a hacksaw blade so it would be easier to trigger. like the switch shown in this video :53 seconds in



a massive switch won't mind sparking but you should use appropriate materials (so it won't heat cause of high resistance) and isolate well yourself from the switch insides
budsiskos (author)  110100101108 years ago
like gold and copper? its also only using 24 volts
no need to go that far aluminium for example is good conductor but idk if it stands sparks well. iron is not as good so i think it should make more sparks as for heating - use large parts of whatever material. resistance goes down when thickness of parts goes up
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