Touch sensitive switching

[jishnudg]

Hey, guys, I just came across this amazing product -

http://www.thetonegod.com/acute_modestscream_overview.html

and I was wondering how the bypass switching works on this..I've had a lot of trouble sourcing true bypass 3PDT switches in my builds and was wondering if this could be a good alternative?
Thanks,
J.

[jishnudg]

Alternatively, could a relay bypass coupled with an LDR setup function (instead of a momentary footswitch) as an alternative to the 3pdt footswitch?

[Mustachio]

Check out tonegod's wicked switches.

http://www.thetonegod.com/tech/downloads/downloads.html

I etched a board for one of these and haven't populated and tested it yet, but it looks promising. But there are a bunch of threads here on the forum about them. Give it a look and search.

[slacker]

Direct from the horse's mouth http://www.diystompboxes.com/smfforum/index.php?topic=91786.msg784338#msg784338 this would then control a relay for true bypass switching or electronic switches, FETS or whatever for non true bypass.

[Jdansti]

Looks cool!  I've looked into capacitive switching but was steered away from it by some of the forum gurus due to the fact that the CMOS devices used in these switches are susceptible to being fried by static or other transient voltages. Maybe Tone God has worked these problems out in his design. 

[amptramp]

You can always go old school:

http://tubularelectronics.com/?p=239

with this schematic:



Replace the 2050 with an SCR and the 50B5 with a power transistor or power MOSFET and you can use a normal regulated supply to do capacitance switching.  Using a 117L7GT / 117M7GT eliminates R3 and the selenium rectifier if you want to remain hollow state.

[jishnudg]

Brilliant But I think I'll try out the Tone God's methods first

[The Tone God]

That The Tone God guy from what I hear is such a jerk...wait a sec.

In the thread slacker linked to I made a mechanical version and a non-mechanical version. The mechanical version is pretty simple. One time I took a bunch pictures but I accedentailly deleted them. I took a new batch of pictures recently and I just need to go through and put together an article. I also need to figure out a better way to post DIY stuff since I have a large load of DIY info in the works.

Anyways the non-mechanical version used a variation of the touch control circuit I use but it is set much more sensitive and there is also alot of algorithm work done by the microcontroller. Still alot of fun.

I seem to remember one builder awhile back using an opto interrupter design for their switching where they had a plunger that broke the light beam. Roger Mayer maybe ?

Andrew

[jishnudg]

An honor to meet you,Andrew, I really like the work you've done on your site

In terms of the switching, I'm kind of interested in using a capacitive plate for it....would love to see a few reference schematics of how the thing is wired up to the rest of the circuit - I'm guessing it'd either be linked to a microcontroller or a latching relay. Any links on that?
Thanks and regards,
J.

[jishnudg]

PS - the schematic posted by amptramp would work, I suppose, but I was looking at something a little simpler...would that be possible?

[The Tone God]

An honor to meet you,Andrew, I really like the work you've done on your site

In terms of the switching, I'm kind of interested in using a capacitive plate for it....would love to see a few reference schematics of how the thing is wired up to the rest of the circuit - I'm guessing it'd either be linked to a microcontroller or a latching relay. Any links on that?

Thanks for the compliment. We have more coming!

The capacitive plate is controlled by a microcontroller. The controller is actually doing alot from generating the clock signal, calibrating (sometimes dynamically on the fly), filtering, debouncing, etc. as well as controlling the relay system, LEDs, and other things. Using the controller go the circuit down to less then 10 parts. It took alot of work so when I decided to ditch the design that kinda hurt. :::sniff sniff::: There is something missing when you don't have something under your foot to smash. It feels...odd. The mechanical plates were a nice compromise. I will post an article of the foot plates when I figure out how I'm going to post future material.

I am planning with doing something with capacitive control for the DIY community as well.

Andrew