Electronics Forum / Basics / October 2006

I'm volunteering at a place out in the country who are living off the
grid. They already have a couple of windmills, which have been installed
professionally. They are also working on a micro hydro system. This has
been designed and partly built by a professional engineer during his ...

Hi to all !
I have connected 19 "small" homemade batteries into one realy,
realy huge battery. After some tests and after fixing some problems
with volmeter, i have this situation:

What is the recombination current?
In a pn diode if there is small injection of electrons in
p-semiconductor, a current (called recombination current) of p charges
borns so the concentration of charges in each section of p is costant

I contacted a battery store in Palo Alto about the battery for an Xli, and
they said they no longer carry them, since they have proven unreliable. This
might be the case. Certainly within three years of having this laptop, the
battery faltered. Any comments on the wisdom of buying a ...

-- Magnetic motor      1, the static magnetic field   1) Motor, Edison
is a classic -- for the motor commutator. It gave birth to a commutator
 Early glory and pride of Health also has its challenges by the AC
motor sad and helpless. (By his own mistakes, for   To the trouble :

I contacted a battery store in Palo Alto, CA about the battery for a Winbook
 Xli, and they said they no longer carry them, since they have proven
unreliable. This might be the case. Certainly within three years of having
this laptop, the battery faltered. Any comments on the ...

How do i see the polaity on a npn transistor?
i got a 2n2222 npn, and i am not sure how the polarity is.
sry, but i am only 14 year old so please explain what you are saying -
and my english isn't soo good either.

I'm making a device for an ROV and need to bring the onboard power of 12V
down to 5V.
After a bit of research I can't seem to find any exact (or near enough)
values for the smoothing capacitors once it's gone through a regulator (I'm

I have been storing my electronic chips in plastic drawers, (Probably
polystyrene). Although I have all of the chips in non-static tubes or
esd foam, is there a way I can make the drawers safer for CMOS chips or
is this adequate?

what can we make use of unity-gain freq? Isn't true we are expecting
bigger gain? what's the point of unity-gain?
there is an equation, Vgs = Ii/s(Cgs + Cgd), (sorry can't draw the
figure). don't understand how to get this equation, isn't it supposed

I am trying to ID a surface mount component and having trouble reading the
part number.
I believe it is a 5V surface mount regulator. The PCB ID is "U1" and the
numbers on it are something like the following:

What voltage do all these compact fluorescent "lamps" use ..?
And what waveform/frequency is required (used) ..?

I am currently studying Kirchoff's Current Law and Kirchoff's Voltage Law
with respect to DC circuit analysis.  I am an amateur just trying to learn
the basics of electronics so go easy on me.  According to the text that I
have, if given this circuit

Hi,
This design says it uses 6V min and 400mA max.
It says it outputs 1-2 watts. Can anyone tell me how
they calculated this power?

I'm trying to build a circuit from
http://www.zen22142.zen.co.uk/Circuits/Timing/24hour.htm
24 hr timer{2}
I could not get the Maplin Relay and I have one I think has close specs,