Electronics Forum / Basics / October 2006

PAL video system uses 50 fields per second and 25 frames per second.
Whats the difference between "field" and "frame"?
Thanks,
Radium

Anybody can tell me where I can buy resistive tape. Any code numbers at
Digikey. I do not mean  electrical tape. I want to use it in an toy
elevator, and will use it to calculate the precise height of an object,
mainly a long voltage divider scheme

Hi, I'm self teaching myself electronics as a hobby so I don't have
an instructor to ask simple questions of so please forgive me if this
has been explained before.
Regarding using Zerner diodes in reverse bias configuration as a

I have a problem that asks about the movement of the second plate of a
capacitor in order to change the resonant frequency by 10 ppm in an LC
circuit.  I am getting stuck in terminology.
Here is the information given:

hey People !
                     For my engg final year project i am in a dire
need of figuring out ways to measure power factor and the rest of these
paramaeters using a microcontroller ..the one i hav selected is

If I wanted to downconvert a 2.4 GHz wireless signal into something I
could run through an A/D converter, what is the easiest way to do the
downconversion?

I posted a message earlier about a piece of test equipment that didn't
come with the power supply and I got some very good feedback.  But as
you know you can't take a chance with voltages or I will end up
damaging the whole thing. It has a a custom chip and two eproms in it

i have a 1.5-3vdc motor that i would like to turn on and off in
opposite directions using two microswitches.  i'm new to electronics,
but from what i've learned so far, i think i want to use a 556 timer
and dpdt relay.  striking a switch would turn on the 556 timer for x

I had the opportunity to re-hab an old natural gas compressor that had
shaken itself apart. I noticed that it used a magnetic pickup on the
flywheel to control the engine/flywheel speed. Tiny magnets were mounted in
the flywheel with a coil fixed to the compressor base. The ...

what is the use of composite signal generator, zero crossing detector
and comparator

The power only comes on for a few hours a day and it is often as low as
80 volts.  I was thinking an 18 volt DC power supply could charge up
some deep cycle batteries when the power is on and the voltage is low
but I can't be there 24/7.

Can anyone tell me if there is a standard for WiFi antenna
plugs/contacts? For instance, Apple laptops have the so-called
Airport card, which has a miniature BNC-like adapter. I wish
to know what kind of contacts WiFi antennas typically use,

I have a circuit that needs a comparator where the negative input will
go 12 volts below ground intermittently.  Standard comparators like the
2903 can't take that, so I was wondering if I could press an op-amp
designed to work on +/- 15 volts into service in this singly-supply

I finally found out the power supply requirements of my ITS 2000S.  It
is +12VDC, -12VDC, +5VDC.
I found a PS that is close but puts out 15VAC and -15VDC and 5 VDC.  If
I want to lower this 15 V down to 12 how would I do this?  Just put a

I'm trying to do that thing and I don't even know if it is possible ...
Powering a car radio with a computer power supply ?
- The Radio is powered by those :
http://membres.lycos.fr/menusia/radio/DSC00796.JPG