Electronics Forum / Basics / July 2008

I have been reading a book about filters both passive and active and
have a few questions about active filters that I need some help on.  I
have a link to pages 109-115 containing the information that I have
questions over.

Pretty self explanatory:  You can join if you figger out how to save a
quadrillion btus /year in oil.
Tweakers and issue dodgers need not apply.
Bret Cahill

As fun as the Woody Allen movie.
Bret Cahill
"The indescrible joy of creation."
-- Steinbeck

A new diesel engine can cull up to 50 kW-hrs from a gallon of diesel.
Since there is no substitute coming on line anytime soon there is no
reason to believe the cost of hydrocarbon fuel will stop spiraling,
especially with China's double digit growth rate, with oil wells

solver’s expertise, the

knowledge or

If you don't like my solutions then post your own.
Either lead follow or get out of the way.
Bret Cahill

I am looking for a circuit that will give me the average of a
fluctuating DC signal.  I am using the term average to roughly mean a
value in the middle but doens not have to be exact.
A few years ago I was told by some people in this group to simply use

Researchers have invented a new material that will make cars even more
efficient, by converting heat wasted through engine exhaust into
electricity.
http://www.theanalystmagazine.com/pr/7010712.htm

http://www.stephenhobley.com/sound.jpg
I have this circuit, the standard Velleman mk103 sound to light kit. I
would like to control 2 20w 12v lamps. I've got some TIP142
transistors that should be OK to do the switching, I just don't know

    --I've been looking *everywhere* for a specific kind of connector but I
can't seem to find any. Ya know those long snap-apart 'sticks' that have
male leads on one end (that can be pushed thru PC board holes and soldered
on the back side) and female sockets on the other? I've been ...

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VISIT MOBILES & COMPUTERS…,
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Diesel power is now almost 4X the cost of the grid.  Battery cost is
2X - 3X grid cost and the combination is just now about equal to or in
some areas already below the cost of diesel.
Unlike electric road vehicles and plug in hybrids, battery energy

I've got a couple of AC/DC power adapters that went to various things
that are no longer around. They have various output voltages and
currents. Would these be useful as a power supply into my breadboard?
One of these is 12VDC but 1.2Amps. The others are all in the mA range.

Stupid question probably but what does the (T1) specification for
LED's mean?
H. Dixon

I'm looking for ideas for building a power supply (out of batteries)
bank that will run a 555 timer circuit and a Kodak Digital camera. The
camera takes a 3vdc supply. I have a number of 555 timers but I think
they take at least 5 volts to work.