Electronics Forum / Design / March 2007

I need a fully differential opamp for my circuit design.
Unfortunately, the simulator I use, multisim, does not have a build in
fully differential opamp.
So, I was wondering if any of you have experience implementing a fully

Hi People.
I am looking at a particular application. I want to build a currency
counter. The device will be based on optical technology. What I want
to do is, "look" at the side of the stack of banknotes and from there,

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another

Hey dudes'n'dudettes
Is there a standard schematic symbol for a digital delay element? I'm
using just a regular buffer triangle with the delay written in it. But
that might be unclear, maybe it means the rise time you know?

Can any one recommend a book that covers the above subjects.
I am particularly interested in differential signaling and things of that
nature
Thanks

So what kind of filtering does an induction heater need?
Potentially salient points...
10kW (240V, 50A USA supply) ultimate goal
~20kHz resonance (may go as low as 5kHz in the future)

I don't know what it is about magnetics..it just never sinks in.. :(
Here's what's on my inductor:
Voltage: 240Vpp 40% duty square wave @ 100khz
Current: +/-100mA triangle wave hovering around 1.5amps.

If electronics has been your hobbly or
profession for many years, I'm sure you've
connected two identical linear regulators.
An example would be connecting two 5 amp

Hi,i'm intereted in learning how to preamplify infrared signals for such a
long distances.I know about the photomodules commonly used in TV's and
VCR's,they have good sensibility,appears they don't saturate if exposed to
the sun light,but the common europeans types,as TSOP 38 and so ...

I looking for a sample data of few frames (<1sec) of a digitized NTSC
signal. Sample freq. of  the data neede as well. Does anyone have such
a file or know a source for one?
Regards

i would like to start for thanking for taking the time to read this
little discussion of mine!
my aim is to produce a battery emulator, and not just any battery
emulator but a zinc-air battery emulator. what i basically have to do

I have a question about FFT. I want to implement Cooley-Tukey FFT algorihtm
but i must know how much RAM i need. I have N samples (24bit) so i need 3xN
bytes for input and 3xN bytes for output and how much more?

we have developed a telematics prototype pcb which has to meet the
class B requirements of EU.It has many cables(like
RS232,USB,DB15,Audio jacks) connected to it.
But certain frequencies emitted by the pcb are very high.

Jim started a cute thread on a.b.s.e. with a pdf post.  Many
if not most of you can't read binary groups, and the messages
are not archived by Google so they soon disappear.  I feel like
a bit of ASCII art, so I'll try translating the thread here.

If an led lamp is rated at 6 vac, and it's put in a circuit that duty
cycles regular incandescants - it has a peak of 18 vac but the result
of the cycling is the regular bulbs light as bright as if they were on
pure 6 vac - question, roughly what percentage of life would be