Electronics Forum / Electronics / December 2006

I'm planning to work on a new project for use in my work.  On the console
of a locomotive there is a 74VDC plug and would like to step it down to
12VDC for use of other electronic devices that would plug into a car
lighter plug.  I though of using a 7812k but I see the max input ...

A magnet was swiped across my TV screen, leaving a purplish swath. Is
there a way to fix this problem?

The warranty card for a portable fridge I received as a present seems
to be a copy of the Engrish version supplied by the OEM.
The sheet contains sentences such as:
"Repair will be offered with charged collected in principle if the

Any idea where I can get help in connecting my PS2 to my PC?  I need
some instructions.

Should be simple to do, but can't find a circuit....
Got a disco ball type lamp that has an AC motor inside it, it's fed by a 12
volt AC input at 500Ma, standard wall wart.
Want to use this thing in a vehicle that only has a 12 volt DC supply, i

Ok, I'm getting a bit miffed at not having my scientific calc on me
when I need it, so anyone know what the smallest *scientific*
calculator currently available is? Something I can *really* throw in
the pocket or lab coat etc.

I have two neighbors that have dogs that bark all night.
Can anyone tell me where I can get a good sized ultrasonic generator that
will travel farther than the 23 to 50 feet that the ones available at dog
Internet sites have?

Any one suggest a good 16F877A devel board ?
I see futurelec have a nice one .
Cheers
Andrew

Can anyone suggest a place (ebay section?) where I can list some bits
and pieces, micro development systems, unwanted kits etc
I am not so interested in the money as them going to a good home.
Thanks

I am attempting to drive 8 logic-level MOSFETs (IRLR2905) with an 8-bit bus
switch (FST3244).  I have a 300 Ohm resistor in series with the gate of each
MOSFET.  Fast switching time isn't a necessity.  I also have a 30V Zener
diode connected across the drain-source to handle ...

I am building a circuit board that will use an ATX power supply as its PSU.
I am trying to find the 10 pin socket that is found on many motherboards
that accepts the main power supply connection.
Having a look at ATX power supply specs, the connector is quoted as being a

My appplication is light detection -> using photodiodes and
transimpedeance amplifier (OPA657 from Texas Instruments). At this
point I have 2-layer working design. I need to increase the bandwidth
of the detector (from 10MHz to 40MHz) and try to reduce noise (also

My uncle went to a good electronic trade school over 30 years ago using a
slide rule. What are the differences in the courses today, if he would take
that 2 year program over again? Thank you.
Bill

Can anyone give me a diagram or help on how to do this..
I've got 3 LEDs, and 3 Momentry Switches.
Id like to make it so that 1 LED is on at all times.
eg.

I would like to build a 12V regulator that will allow me to place a
cigarette lighter type connector on any supply from 12V up to 24V and be
assured that I'm always going to have 13.8V at the output.
I need a circuit that's going to regulate anywhere between, say, 12V and 30V