Building a cap/resistor switch box...which rotary switch?

[spy590]

In my quest to learn the "why" in a lot of these circuits, I've decided to build a little box to assist with testing cap and resistor values. I've seen plenty of kits for this, but I thought it would be a fun little tool to build and I already have a bunch of components laying around. I'm going to use a chunk of bread board with a rotary switch. The bread board will let me swap out a group of values quickly without having any permanent values in this thing.

A couple of questions for the group:

1. For the rotary, shorting or non-shorting? Not sure what is appropriate for pedal circuits.

2. Connecting to the circuit. I'm envisioning a couple of alligator clip leads, but is there something out there that is designed for quick connect to through-hole type boards? Some sort of springy pin type deal would be awesome...I could just "plug" the leads into the appropriate holes on the pcb and test away...

Russ

[jkokura]

I don't know for sure about the first. You could probably google the difference and figure it out if you wanted, that's all I'd do.

About the second, I've thought about this too. There is no 'plug and play' sort of idea like you're recommending. In order for most circuits to work you need to have solid and permenant connection between the parts, and on a PCB that means solder.

There are two ideas I've had. One is to use typical SIL sockets installed to allow you to use a wire to simply 'plug in'. The other is to use a header pin on the PCB, and a socket on the wire. This would be a little stronger connection in my mind. I actually want to build some 'prototyping' enclosures with permanent switching, LED and jacks for me to hot swap PCB's I'm building to test them out. I'd install the header pins on the PCB.

In both of those ideas though, you'd have to remove the sockets or header pins in order to solder in permanent parts or wires. If that's cool with you, that's the route I'd go. Otherwise, maybe someone else has an idea.

Jacob

[spy590]

I don't know for sure about the first. You could probably google the difference and figure it out if you wanted, that's all I'd do.

About the second, I've thought about this too. There is no 'plug and play' sort of idea like you're recommending. In order for most circuits to work you need to have solid and permenant connection between the parts, and on a PCB that means solder.

There are two ideas I've had. One is to use typical SIL sockets installed to allow you to use a wire to simply 'plug in'. The other is to use a header pin on the PCB, and a socket on the wire. This would be a little stronger connection in my mind. I actually want to build some 'prototyping' enclosures with permanent switching, LED and jacks for me to hot swap PCB's I'm building to test them out. I'd install the header pins on the PCB.

In both of those ideas though, you'd have to remove the sockets or header pins in order to solder in permanent parts or wires. If that's cool with you, that's the route I'd go. Otherwise, maybe someone else has an idea.

Jacob

I suspect the first won't really matter at pedal voltages--just curious mostly. For the quick connect, I leaning towards sockets and tinned leads. I tend to socket the "swappable" parts these days anyhow, so that will be inline with my current process.

+1 on the enclosures for pcb testing. I built a beavis board of sorts a while back, and I've used it with pcbs instead of the bread board plenty. Thanks J.

[sgmezei]

My buddy just picked up a bunch of these from Weber for amp builds and he really likes them. Just in case you didn't see them:
https://amptechtools.powweb.com/subs.htm

Where did you find kits for these? I am going to follow this thread as well because I want some sub boxes eventually too. The Webers look great, but mine don't need to look that good or cost $40.

Also, for the testing phase. You could use some thicker leads (like from a 1n4001) and solder them in leaving them long. That way you can alligator clip them easy and you have something to hold on to when you want to pull them out.
You could also use shrink wrap or electric tape to make sure the leads don't short something else out.

[spy590]

Here is the most recent I came across on Amazon. Let me know if that link doesn't work--I'm posting from my phone.

http://www.amazon.com/gp/aw/d/B0002BBQMI/ref=mp_s_a_8?qid=1322071620&sr=8-8

Here is the resistor version
http://www.amazon.com/gp/aw/d/B0002BBQLY/ref=mp_bxgy_p_dp_y?qid=1322071620&sr=8-8

Your lead idea would work well with the gator clips.

[spy590]

Here is the finished product if anyone is interested. All I could find locally was a 2 pole 6 position rotary, and modified it into a single pole 12 position. Rather than using fixed capacitors/components for each position, I decided that I wanted this box to be used for generic components. To accomplish this, I wired a 24 pin socket (2 rows of 12) to the top of my box, so I could freely swap out caps, diodes, resistors, or whatever else I wanted to A/B in my pedal.

Here are some pics with 4 different diode/LED clipping combos loaded up that I'm testing in an 808 clone.

[spy590]

Forgot to mention, I also found these EZ-Hook test leads for easy connections to through-hole boards. I grabbed a pair that I can attach to the gator clips that I have on the box.

http://catalog.e-z-hook.com/viewitems/test-hooks/ll-categories-test-hooks-e-z-micro-hook-lock-hooks?

[nzCdog]

Dang! Thats a cool idea! nice work

[spy590]

Thanks! It's been quite useful so far--In this case it was cool to A/B a bunch of sym/asym/silicon/led combos all at once. Since IC sockets are "stackable", you can even have a set of them preloaded with various clipper or cap combos that you use to test often.