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Re: Need funny footswitch


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2/12/2006 7:44 PM
Andrew M
Re: Need funny footswitch
Do you have a copy of "The Ultimate Tone"? There is a section in the Switching Methods chapter (pg 9-59) about "Alternate-Action Switches Used as Momentaries in 2-Way Foot-Controllers".  
 
Andrew.
 
2/13/2006 1:21 AM
Rick Erickson

quote:
"There is a section in the Switching Methods chapter (pg 9-59) about "Alternate-Action Switches Used as Momentaries in 2-Way Foot-Controllers"."
 
 
Let me guess - there's two capacitors in series with the switch contacts of a DPST, and a resistor across each of the caps to drain them. The common terminal of the switch goes to ground and the caps join together at the jack tip contact. Adjust values to get desired results. If you do this with a momentary switch you get an interesting effect - fast operation of the switch gives you normal push to set - push to reset action. But if you hold the switch down for a couple seconds and then release it the effect will cancel, as if you had pushed the switch twice.  
 
RE
 
2/13/2006 8:36 AM
Andrew M

Its not that fancy. The center terminal of a DPST is tied to a low voltage, the other two contacts are tied high through a resistor. The output is normally low, but when the switch is pressed it momentarily goes high as the switch changes position. ( I guess this would be a break before make switch?)  
 
I guess a picture is worth at least 48 words.  
 
A.
 
2/13/2006 3:53 PM
Rick Erickson

quote:
"The center terminal of a DPST is tied to a low voltage, the other two contacts are tied high through a resistor."
 
 
Yeah, I follow that. I've used the capacitor trick in a couple different applications. It's a neat trick to get a pulse from a push-on push-off type switch, or to momentarily sink a voltage to ground.  
 
RE
 
2/15/2006 1:21 PM
TEM Why not just
open up the switch and remove the latch?  
 
Charlie
 
2/15/2006 3:30 PM
Rick Erickson

quote:
"open up the switch and remove the latch?"
 
 
Tech: Your power supply has a short.  
 
Customer: Well - can't you lenghten it?
 
2/15/2006 3:33 PM
Rick Erickson

quote:
"lenghten sp"
 
 
lengthen  
 
Darn dyslexia!
 

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