A crossover clipboard (switchboard) that really works
Anyone who has ever tried to develop a loudspeaker certainly knows the problem of the often necessary component change in the development switch. Various solutions This is as convenient, quick and above all as possible. In this regard, "in circulation" must be designed to be reliable in terms of measurement technology.
In the sound and sound 3 / 2007 has been a switchboard with the cheap speaker terminals. I had ordered a bag full of such terminals. After the inspection of the terminals, I decided not to set up the switch board.
The problem with these terminals was the too high contact resistance. A thin and very soft sheet of metal is pressed onto even softer plastic, and the whole thing with the power of, let's say household rubber ... How should a connection be made that is equal to the soldering point?
Not much better cut for this purpose gladly taken crocodile clips. Contact resistance of ~ 0,3 Ω is not uncommon.
All that remains is the reliable, but not exactly comfortable luster terminal, or do all soldering ...?
A small linked picture in the Diy hifi Forum But then I still got on the funnel ...
The alternative is called Wago, and looks like this:
To understand why these clamps work so well, I recommend the following video:
(Product information from Wago)
So, off to the hardware store (better of course to the local electronics retailer) and 2 packs purchased and glued with hot glue on a piece of pressboard:
The finished crossover clipboard
In this case, an 2 way execution. Red is the plus lead, blue goes to the drivers, black the mass. Time required approx. 20 minutes. Cost ~ 15 €.
The orange levers are clearly on train. There is really tension behind it. If you take the connected components out again you can see that there is actually a notch in the metal => If you often install and remove the same component, the wire will break off at some point. It is best to apply stranded wire to the components and tin the ends. The images of the Wagos take everything up to 2,5mm². Regardless of whether it is a solid cable or stranded wire.
Lines that are "permanently" installed should also be tinned to prevent possible corrosion of the copper.
What should also be mentioned: The board is extremely flexible, and some possible applications only become apparent during use. Measure only one driver? Click-cable-pull-measure-plug-click-ready ...
But now to important part: How do the Wagos beat compared to soldered components?
To find out, I first 6 resistors á 0,15Ohm first in the terminal board in series and then soldered the same resistors and measured both variants.
With quite a surprising result:
The soldered variant has higher contact resistances than the Wago variant (0,002Ohm distributed over 5 connections).
To make sure that no solder joint was faulty, I still measured these individually:
R <= 0,001 ohms. The result was the same for all solder joints.
At the end...
It can definitely be assumed that the turnout created on the "Wago clipboard" will be congruent with the soldered one. In developing the Direct-HA Edition the switchboard came into action for the first time and did exactly what it should do. The measurements of the soldered points were identical to those of the terminal board. Also came to me the idea to build series in some of my points Wagos, eg. for the voltage divider of the tweeter, in order to carry out modifications easily and quickly at any time.