Electronics Forum / Basics / May 2007

I have got a problem with a digital circuit. I got a signal from a
comperator, which changes from 0 to 1 and back. Now I want to catch
the first high signal and hold it until infinity. I try to use a RS-FF
with R = 0 and S = 0,1,0,1,... (my input-signal) , but I got, of

I have a circuit that I built years ago. Rather than just replacing a
bunch of zener diodes, is there a way to test them in circuit, without
powering on the circuit?
I know that surface mount zeners fail shorted, but they can open if

This looks like a pretty cool circuit:
http://www.redcircuits.com/Page55.htm
However, where would I purchase a set of ferrite rods?  I checked
Jameco and Radio Shack, but no dice.

  I try to send vedio from cctv via telephone line I connect the cctv
camera output to ADC  and the output of the ADC to Atmel 89c51
micocontroller to send the data serial but I want to connect the
output of the atmel89c51 to the telephone line

We are looking for an off the shelf enclosure which will hold a
speaker and have an opening
for  batteries(battery compartment).
Other than those basics we are very flexible.

I was wondering if anyone knows the pinout for the standard 15 pin PC
monitor connection.  I found talk of it from sketchy sources like
http://acl.co.uk/pinouts.htm, but then I found other sites that
contradict that.  I'm hoping for something authoritative if possible.

My brothers and sisters everywhere! With this essay, I am not singling
out the adherents of Islam - to which I ascribe - but rather I am
writing this essay to every man and woman throughout the whole world.
I ask Allah that He facilitates tat this essay reaches every ear,

I'm replacing the front turn signals on my motorbike with LEDs.  The
LED light is rated at 0.4w at 12 volts, and the globe it is replacing
is 21w.
When I connect the new LED light to the original wiring, the turn

Apart from the inductor and rectifier simply being in different
positions, what is the difference between the boost and Buck-boost DC-
DC converter?
Is one more reliable than the other?  Is one more energy-efficient?

hi have are you

Just got VoIP and videophone. Anyone have tips for tweaking?

Good day!
I'm looking at the following products:
Electret Condenser Microphone
http://www.knowlesacoustics.com/images/specs/MB6022APC-1-A-2004-06-01.pdf

when i was looking for something about transistor i saw this group and
i have  just joined the group.
i live in turkey and work for company which detects the faulties on
electronics boards and fix them.

I have a device with 34 digital (5V or 0V) inputs. Only one of the 34
can be 5V at any one time. I'd like to know the number of input which
is at 5V. I can think of two ways of doing this:
a) 5 eight-bit shift registers. Each input is connected to a shift

I have built a flatbed printer from an old Epson 640 but need to fool the
printer into thinking there is paper in, when the drive stepper is disabled
I have tried timing relays but can't get it right. Does any clever person
know how I do this. This would be a great project if it ...