Wicked switches

[Radamus]

I recently purchased the parts necessary for the momentary switch (w/ flip flop, inverter) set up in the wicked switches article (http://www.geocities.com/thetonegod/switches/switches.html). I went into a store to find all of the parts and I couldn't remember what I needed, so I wound up buying 4025's instead of inverting circuits. The 4025's work, they're just three in Nor gates, so I have to connect three inputs and I have an unnecessarily large IC. I printed out the stat sheets for the 4025, 4066, and 4013. I just had a few questions about the process.

1. There is either voltage from Q or Q'. Which one is supposed to be the "on" setting?

2. A general question about IC's: There's Vss and Vdd. Which one connects to hot and which one connects to ground?

3. I know the 4066 is supposed to be 9v, but what voltage should I give the others, and what kind of resistance do I need to make that happen?

4. I bought really cheap momentary switches, but they seem to be small and somewhat fragile. I'm not necessarily looking to "stomp" on it, but does anyone have recommendations for something maybe a little better that doesn't approach the cost of a DPDT or 3PDT?

5. Is there any benefit to having one switch dedicated to turning the power to the circuit on and off? It seems like most circuits just leave the power connected all of the time, and I was confused as to whether this drained the battery or not. If I'm using 9v batteries, I want to make them last.

Thanks in advance.

[GibsonGM]

Hi Conrad,

Try searching Google for "LM4025 spec PDF" or something like that. It will list the supply voltage.  Use the actual numbers on the chip.
"on" and "off" are just relative (opposite) logic states...I would not worry about which state is on or off if you are using a momentary switch...
Vss think of as 'supply', or +
Vdd think of as drain, or -.

Many chips won't take more than 5v, check that spec sheet.  To lower it, you'd need to make a voltage divider or use a Zener diode...searching for a Wiki or tutorial on "voltage divider" will get you good results.

I've seen plans for adding a big pad to engage the small momentary switch, try over at GEOFEX...that's the way Boss and those guys do it.   Switches don't use additional power so no worries, altho I would not have an 'on/off' switch on my effects, just a pain in the @ss. 

Hope this gets you started!

[Radamus]

I checked all of the spec sheets. They have wide ranges of acceptable voltages, but I just don't know enough about electronics to know if I should apply the full 9 volts or less. The reason I want to know on and off is so I know when the LED should come on. I suppose I can just put it together and figure it out from there. And the power question was directed at the entire circuit always having power, but mostly not having signal. Is this a waste?

Thanks for the recommendation about the switch. I'll check that out now.

[any]

1. There is either voltage from Q or Q'. Which one is supposed to be the "on" setting?

2. A general question about IC's: There's Vss and Vdd. Which one connects to hot and which one connects to ground?

3. I know the 4066 is supposed to be 9v, but what voltage should I give the others, and what kind of resistance do I need to make that happen?

4. I bought really cheap momentary switches, but they seem to be small and somewhat fragile. I'm not necessarily looking to "stomp" on it, but does anyone have recommendations for something maybe a little better that doesn't approach the cost of a DPDT or 3PDT?

5. Is there any benefit to having one switch dedicated to turning the power to the circuit on and off? It seems like most circuits just leave the power connected all of the time, and I was confused as to whether this drained the battery or not. If I'm using 9v batteries, I want to make them last.

1. hook up led's to the 4013's q and 'q outputs (+ side of the led to 9v through a 5k resistor), switch power on to the circuit
and see wich led is lit. That's the output that goes low when the circuit is switched on. Since the 4066 switches are inactive on low, you want that one to be the
bypass setting. (so it comes on with the effect bypassed.)

2. Vdd=Positive supply +voltage
    Vss=Negative supply, ground

3. From what I know, all Cmos (i.e. 4000 series) is designed to work on 5 volt although some tolerate higher voltages, like the 4066.

4. I'd say make your own actuator (the thing pressing the switch) out of whatever you have around the house, as long as you have control over
the amount of travel. Then use a tactile switch or similar for the momentary, basically the way switches in a Digitech pedal work.

5. The common rule is to connect the negative side of the battery to the "ring" of the input jack (which means it should be a stereo jack)
this way power is switched on by inserting a cable and off when the cable is pulled. Use a switch if you want just a spst between the
negative battery lead and ground.

Cheers

[Radamus]

I've spent about two hours trying to assemble one of the wicked switches, and what has occurred to me is that it is a real pain in the ass. SO I had a thought. The downside to using a DPDT is that you can't easily connect an LED to it. The downside to using the wicked switch method is that it requires connecting various little stubby legs from three 14 pin IC's to one another. Or, you can use a DPDT to control a 4066 and an LED. The middle pin on one side connects to hot and the two positions connect to the control elements of the 4066. The other side of the DPDT makes an LED work.

I found that the wicked switch method uses three 25-30 cent IC's, perf board space (50-70 cents), a momentary switch, and, possibly, an actuator, totaling above two dollars. Some sites have DPDT's for that price. Add on 30 cents for a 4066 so as not to have to do a millennium bypass.

So the questions I have now are:
1. Am I doing something really wrong that would make soldering the IC's harder than it should be? Does anyone prefer this method? Why?
2. Will the idea about the DPDT work? What would it take? What are the downsides?

I'm going to finish this wicked switch, but, if the alternatives are good, I don't think I'll be making another.

Thanks in advance.

[any]

I found the wicked switches to work fine, I would actually use sockets for the IC's so you can swap them if they ever go bad.
It might eat up some board space, but it's more flexible, easily scalable (hook up a second 4066 to double your switching)
and in parts still cheaper then a 3pdt switch which eventually will wear out.

Then again, I usually use a 2PDT or 3PDT for my bypass switching.