Electronics Forum / Basics / March 2007

I was using 555 astable output and connect to a radio transformer
( 1:70), trying to step up the output voltage from pin 3. Somehow I
could not measure any output from the secondary coil of the
transformer. Is there anything wrong with this set up?

I've build a Jacob's Ladder with an old "Franceformer". The specs
are:
Input; 120 volts - 60 Hz. Output;14,000 volts- 30 Ma.
If I wanted a bigger show and had two identical transformers, could I

I have been given a large number of LEDs soldered into a board.  Since the
pins have been cut t the same length what is the best way of determining
their polarity when removed from the board?
R

Pal:
I have a question regarding the unit of capacitors. I thought the
units are pf, u, or f.
For example, a capacitor could be 0.01 uf; another could be 470

I've been looking around for a book on fixing telephones--not ancient
models but not new cheap junk either.  Haven't seen anything that
looked good...  Any recommendations?
thanks,  Guy

Hi  I would like to know what course, or how to learn to repair
Electronic equipment to component level.
Such as TV'S motherboards, dvd's etc...
There is a City and guilds course:- Electrical and Electronics Servicing -

I found out that my DMM  can measure hFE for transistors, but when a
correctly place a transistor in the slots the numbers wobble a little
then settle to a 1 as the only digit shown on screen. What am I
supposed to be looking for? Does this mean the transistor is not

I want a link to my web page from a posting on a classifieds (homes
for sale) site.  I want to copy the address from my browser and
consense it to a simple phrase that the user can click on and link to
my web page with he info on the home...can anyone help with that?

Hi, gangs:
This is Daniel. Ealier I posted a question on choosing a Ge
Transistor.
I really appreciate all your assistance. I think I found what

http://www.spikedhumor.com/articles/90173/Homopolar_Motor.html
Check out this little simple motor this guy made. Coolest thing!

Wondering whats the implication of increasing the filter length of a
2D FIR filter? wat are the applications of a long filter length (eg.
N>40) in image processing?
Thanks alot

Anybody know of a reasonably priced crimp tool for Molex 50079-8000 or
50079-8100 crimp terminals? The Molex tool is 63811-0300 but it sells for
around $200.00 so I'm really looking for an Asian "knockoff".

1)  CAN SOMEONE  TELL ME HOW CAN I READ MEMORY FROM GSM SIM WITHOUT
USING CELL PHONE .. I MEAN I WANT TO INTERFACE  GSM SIM DIRECTLY TO MY
PC TO READ ITS MEMORY
2) PLEASE TELL HOW CAN I INTERFACE MY CELL PHONE MEMORY WITH MY

I just got my first transmittor to work.
I know this is small stuff to most of you, but I've only been studying  
electronics for two weeks.  The success tells me I am interpeting the  
schematics correctly.  Although I did have the transistor pin  

In school (if memory serves) I learned that a bipolar transistor is a
current-controlled current "amplifier", and that a FET is a
voltage-controlled current "amplifier". Replace "amplifier" with "switch" to
complete the 2x2 matrix I learned about most uses for active devices.