Electronics Forum / Basics / December 2007

I'm working on a project in my free time and I think I have a
generally good design but I there are two or three issues that I need
to address before I start building a prototype.  I'm sure some of
these are basic for experienced electrical engineers and the likes but

I found my way to this page today:
http://www.gizmology.net/LEDs.htm
looking for information about light output.
As I was reading, I found a circuit for regulating the current through

I am new to this newsgroup, I am typically a poster on rec. pyro or
metalworking, but I have been working on a new project. I am trying
to
make an ignition coil for my new turbing engine, and I am quite

I was wondering if it was possible to build a power supply that steps
the 240 Volts AC mains to 12 volt DC 200 mA.  I know I could use a
wall transformer, but that would be to bulky for my little Tunecast II
FM Transmitter.

i am using a lockin amplifier for the 1st time other than a canned college  
lab demo
i have a 5mV signal from a strain gage that is driven with 10Vpp at 1kHz  
or whatever i choose.

I have am a little confused here about the inverting and non-inverting
mosfet drivers TC4429 and TC4420.
*********************************
From the Microchip datasheet:

An old project that I'd been working on is that of an electric fishing
Kontiki. I have a circuit that I think will work O.K. but I hope that
someone could take a look at it and point out any glaring mistakes.
In particular the mosfet motor driver circuit is of concern to me.

I have just joined this groups.
Warm wishes to all.
I need to know how to use a HP Agilent 332501A 80Mhz function
generator to generate a single pulse of 3.3V with duration of 3 m sec.

any one can provide a good method to learn mesh analysis

I'm working on a school project where I need to compare 16bits (4 BCD
values) from a CMOS logic system and need alternative ways of doing it.
So far I've got 4 cascaded 4063 bit comparators, ADC conversion but I'm
struggling for a third. Can anyone suggest a method?

apparently there is a well-defined impedance between any two terminals
in an electrical network that contains only passive components
(resistors, capacitors, inductors, independent power sources). why is
this the case? any help would be very much appreciated.

yes i googled and found lots of different mods to the basic 5v
*7805* regulator power supply  that is {AC in, bridge, 7805, 5v
out}
my questions are concerning the various mods/enhance such as ;

can anybody plz tell how do we measure cahracteristic impedence of a
cable, may it be coaxial, stp, utp or power cable.it looks impedence
matching and trying to get the maximum power. i s there any other way?

Q1- Capaitors are open for dc frequency why.?
Q2-Capacitors are short for AC analysis is generally short. why..?
Q3-For what frequencies, we open capacitors even when we are doing ac-
analysis.Why we do so ?

I'm thinking of buying the Antique Electronic Supply one tube
transmitter, but I need to swap the transformer over for one that
handles 240 volt, gives out 125 volts.  Can anyone tell me of any
Australian online sources for this?