Electronics Forum / Components / April 2006

Has anyone seen the capacitor code printed on surface mount capacitors, all
the surface mount capacitors I have seen in New Zealand sold for
manufacturing are blank. Most resistors are marked, e.g. 223 equals 22K Ohms

Hello newsgroup,
we are three enthusiasted electronics amateurs and we got that idea into our
heads to build our own splitter box. I have a ISDN+ADSL connection at home.
Based on that connection we would like to separate the

Is there a minimum level of relative humidity, below which computer equipment is
damaged?
I bought some antique handheld computers. I want to keep them in pristine
condition for a very long time, fifty years or more. I want to know the ideal

My GF owns a Sony Network Walkman NW-E50 (MP3 player). I assumed that
all Sony products must use Sony's music software. But I was wrong as
the MP3 player contains a built-in File Manager. That means she could
plug it into any PC (Internet Cafe, etc.) and transfer songs to and

Any ideas what an NT407F is?
My best guess is it's a MOSFET, TO-220 insulated package, probably 400 to
800V, a few amperes Id, and enhancement mode.  The only thing I can find on
the internet is a specious link between the acronym "MOSFET" and the part

I was in my local newsagent in London and saw he had a card of button
cells behind the till which he was selling at £2.99 each.
I recognised the card of cells as one which I can get from my local
pound shop for £1.  It contains about 16 cells.

Can someone tell me which wire does what in a Nokia HDC-5 handsfree.
See <http://tinyurl.com/p5rsd> for a picture.
This personal handsfree was used for the 8310, 8210, 35XX, 33XX, etc.
The plug is a 2.5 mm jack with a main connection plus three rings.

I am building up an Elektor project pcb which calls for a pcb mount
rca jack from Monacor International (part T-709G)
http://www.monacor.com/int/en/startseite.html?spr=EN
(To avoid problems with long url type the part number in the search

I am investigating op amps, and would like info or a website showing
the internal circuitry of an op amp, not a 741 though. ie taking
circuit diagram and breaking it down to see what its doing stage by
stage? ie current mirrors + darlington pairs. I wuld like a decent

Hello, I am looking for IC datasheets for Mitsubishi analogue ICs - M51720P and
M51721L. I noticed these are components widely available from many component
distributors, but have a hard time finding the datasheets from them on-line.
Would be interested to hear from anyone that ...

Hi, I have looked at CA3140 data sheets and seen that the output can reach
close to the positive rail on a split rail supply, and (allegedly) right
down to the negative rail.
This isn't as clear as it should be. First, on a single rail supply, the

I removed some small electolytic capacitors from a modern circuit board
to use elswhere which meant that the wires of the electrolytics were
really very short. I then soldered some "extension" leads onto the
electrolytics.

I disassembled a guitar amp, in order to re-solder a bad solder joint.
Now, I need to put it  back together.
The PC board has a metal plate screwed onto it.
That plate also screws on to the metal chassis.I disconnected the

I rec'd a cooked UPS unit, outputs were shorted and smoke was seen.  Opened
it up and there are four rows of 5 output power transistors.  Two rows look
fine, two rows are blown so badly it looks like there was actual flame up
the <huge> heatsinks.  Bunch of resistors in the general ...

Just tried to contact Holtek to get a list of their Uk distibutors - the web enquiry form on their
site is not working (fieds not writeable in firefoc, no submit button in IE), and I can't find any
email addresses.
Anyone have an email contact for them that's known to work?