Switching problem

[jjj]

I'm having yet another switching problem:
I want to make footswitch, which turns on an effect. The problem is that, when the effect is switched on, it requires to activate the switch another time to turn the effect off.

I want to eliminate the latter. That means, I want to press the pedal only for as long as the effect is needed and when I let the pedal go, the effect should turn off.

That also means that the switching circuit needs to automatically activate the switch another time to turn the effect off.
How can that be done?
Click Image to Enlarge Image Hosting

[Enzo]

Is this the same pedal we were working on recently or is this something else?

This is exactly what you did to that pedal. You want to turn the flip flop into a straight switch.

[oc disorder]

You need a non latching momentary push switch.
How many connections does the switch require and are you trying to modify an existing pedal ?

One way would be to use a relay which would need a power supply and a single pole momentary switch.
The relay could be wired to completely bypass the effect (aka trew bypass sick of that phrase now..do heart surgeons do true bypass ? I digress..)which would have to be left on...

Holding your foot on the button keeps the relay closed
taking foot off opens relay bypassing the effect.

Thats a basic quick way although there could be some clicks or pops when the relay switches.
Should be info on the net re relays.
addendumAhh course ENZO is spot on thought it was uinrelated

Well using a relay eliminates flip flop theory.......

[jjj]

Hi Enzo,

I was thinking the same... but no, it's nothing to do with the TR2.
This time it has to do with www.live-styler.de PC Key Control 244/245, which
now allows me to switch the YamahaStyles accompaniment via 2 switches (from the PC-Keyboard) from major to minor or seventh chords.
So it's a totally different ballgame.
The trouble is that when I want to switch the accompaniment from major chord to minor or 7th chord, I need to press the PC switch another time to cancel the chosen minor or 7th chord, before I can switch back to a major or over to a 7th chord.
I hate that, because there's no time for it; also it would be pretty confusing.
That's why I want to only have to press the knee lever once for either minor or 7th and when I release (or don't touch) the lever, the lever stays invariably in (the center) major chord position.

[jjj]

Hi oc disorder,

It's actually a knee switch. To simplify it I called it a "foot switch".
It has to do with www.live-styler.de PC Key Control 244/245, which now allows me to switch the YamahaStyles accompaniment via 2 switches (from the PC-Keyboard) from major to minor or seventh chords.

The trouble is that when I want to switch the accompaniment from major chord to minor or 7th chord, I need to press the PC switch another time to cancel the chosen minor or 7th chord, before I can switch back to a major or over to a 7th chord.
I hate that, because there's no time for it; also it would be pretty confusing.
That's why I want to only have to press the knee lever once for either minor or 7th and when I release (or don't touch) the lever, the lever stays invariably in (the center) major chord position.

If everything fails, I'll have to use two 3-position momentary switch, like the mechanical switch shows... but maybe there's a more lasting electronic solution?

Another problem I'll have will be: how to get the two PC Kbd switches wired up?

[Steve Conner]

There's a program called Autohotkey that allows you to transform one keypress into a sequence of keypresses. If your controller is based on a PC keyboard, you can use this to add a "cancel chord" command.

[jjj]

Hi Steve Conner,

Thx for that kick! That's some lateral thinking! Autohotkey... I'm going to chase that up.

[jjj]

A L A R M... E R R O R ! ! !

Sorry, I have to start again...
The way it looks, I need to reveal "the whole, boring story" how I want to apply this switch/ switches.

It's actually not a footpedal, but a knee lever control, which has to do with www.live-styler.de PC Key Control 244/245. Confusing and boring, I know!

Now it allows me to switch the YamahaStyles accompaniment via 2 switches (from the PC-Keyboard) from major to minor or 7th chords.

The trouble is that when I want to switch the accompaniment from major chord to minor or 7th chord, I need to press the PC switch another time to cancel the previously chosen minor or 7th chord, before I can switch back to a major or over to a 7th chord.

I hate that, because there's no time for it; also it would be pretty confusing.
That's why I want to only have to press the knee lever once for either minor or 7th and when I release (or don't touch) the lever, the lever stays invariably in (the center) major chord position.

I also just realized that my previous mechanical switch was wrongly drawn, because PC-Kbd keys can only be momentarily switched!!
That means: first, when I press the knee lever the PC-Kbd key has to be briefly activated (to turn on the effect) and when I release the knee lever, the same PC-Kbd key has to be another time briefly activated (to turn off the effect).

[jjj]

Hurray!!!
You won't believe it, but I successfully connected the two PC-Kbd switches with two wires on each key. I was a watchmaker job!
I unscrewed the cheapo-China Kbd and then measured the connection between key contact pad and the terminal to the chip of the two plastic circuit layers.
The hardest was to solder hair-thin wires onto the
crowded, narrow tracks to the chip.
I used a low heat solder iron with a fine tip, pre-soldered the wire as well as the track and then just quickly soldered them together.
Now I have got a plug with 4 terminals on the keyboard hanging and it works a beauty!
So, my 45 years of hobby electronics fiddling experiences payed again off.

I wished I could buy a conductive glue. I have to search the Internet for it. Maybe there exist such a thing?

[oc disorder]

http://www.wireglue.us/ naturally !

[jjj]

http://www.wireglue.us/ naturally !

Thx for that! I found that, too. Even thought of filing up some silver and do my own Lab tests, by mixing some silver dust with a tiny drop of UHU glue or water-based glue. Also, using graphite powder... as one chap did.
Here in Chile town (Quilpue), where I live... I'm remote from modern civilization. Here only the basics are available.
At least fruits, veggies, bread, wine and women are bueno y cheap ! You can't have it all.

[jjj]

I thought my switching problem is solved, but now I'm thinking a step further:
how about implementing this switch into my 120-button accordion bass?
That would allow me to press any bass & minor/7th button to control the Live-Styler.de (YamahaStyles) accompaniment. That would be surely better than having to knee a lever!

For that I would need electronic switching. Of course I could do it electro-mechanically, but that would require more power and would be noisier.

So, my question now is: How to render this mechanical switch (below) electronic?
(I'm not sure if the PC-Kbd switches respond to fast pulses?)

[Enzo]

You would need to make a "one-shot" that is triggered by both rising and falling edges on the control input.

[jjj]

Hi Enzo,

Yes, it got to be something, which turns the switch momentarily on, when I activate and then another time momentarily on, when I deactivate the switch, as the mechanical SW would do it.

Ideal would be a collection of all possible switching options, because it's always the same dilemma. Long time ago, I saw such circuits, which showed the electronic equivalents of mechanical switches.
You Enzo, can device such a solution out of the blue, because you have got the knowledge. I can only search through piles of electronic circuits, in the hope to find something suitable.