On 06/02/12 19:01, Tony Duell wrote:
Is that _all_ you hurled at him? I would have
thought a medium-sized
mains transformer would be a suitable missile here :-). Even more so if
it has exposed connections and is plugged in at the time...
He was extremely lucky. And I haven't seen him since :)
Right :-)
Take the keyboard apart, clean the membeane pads
and the LED leads with a
Q-tip and propan-2-ol. For obvisou reasons don't try to solder to the
membrane sheet...
Well that's a given. The melting point of solder is, after all, much
higher than that of plastic...
I would love to see you melt PTFE with a noraml soldering iron :-)
In other words, it depends on the plastic. But the melting point of
keyboarf membrane sheets, at least all the ones I've seen, is much lower
than that of normal soft solder.
And surely you
know how to test LEDs... (analogue ohmmeter, some DMM
diode test ranges, battery and resistor, etc)
... Peak Atlas DCA05 Semiconductor Analyser? :)
(As in, the little blue box which IDs the pinout and basic parameters of
transistors, diodes, FETs and so on)
I've seen it, I don't have one. The doucmentauton is IMHO inadequate for
such a complex device. If I need to know more aobut a transistor/diode
than a simple multimeter test will tell me, then I fire up the Tekky 575...
The multimeter works too, but only just -- the DCA will drive the LED at
a decent brightness, the DMM requires that the bench light be turned off
in order to see the LED...
Right... I use an analogue meter for this. On the Ohms*1 range it'll
light every LED I've tried.
However, even if the DMM doesn't pass enpugh current to get a decent
glwoe from the ELD, it will display its forware votlage drop (I assume
you have a 3+3/4 digit meter). And that will pick up open-circuit LEDs.
One of
the many alternative uses for a roll of 'rainbow' IDC cable :)
I often use an offcut of stripboard or a DIL socket/IC for this....
I guess you meant "to ID the pin spacing" -- I meant "to work around the
issue of mismatched pin spacing".
Ah, OK...
I've got a small ball-head hobby vice for some of
that, a Panavise with
PCB holder, and the obligatory set of Helping Hands. The Panavise gets
the most use.
I've never needed one (or the 'helping hands' which I think I haev
somewhere, but haven't use since the day I was given them). I have got
quite good at holding a PCB between middle and 3rd fingers of my left
hand, using the little finge to suppor the component, thumb and index
finger to feed i nthe soder while my right hand holds the soldering iron...
(I also have a set of hand-crimpers for IDC plugs... somewhere...)
Oh, I know where mine are, in the same toolbox as the modualr plug crimp
tool. The latter gets quite a bit of use, but I prefer to crimp ICD
connectors in the vice.
Indeed...
There are some phono plubs with a sliding sleeve on the
outside so that the ground makes first, but they are not common...
I was wondering if anyone had done that...
I can't rememebr where I saw them, but it was one of the well-known
connector manufacturers who made them.
Sounds like something Neutrik would do.
That's who I was going to say, but I didn't have any way of checking...
I have an LM386-based bench amplifier for that. Even
has a built in
speaker, and a volume control labelled from 0 to 11 :)
I think an ECL86 would be preferable for that application.
-tony