Electronics Forum / Basics / August 2006

We are kinda lost in the sauce on this one. The attached link has the
schematic we are trying to bring together. If any of you guru's can see
whats missing, please let us know.
Thanks in advance,

We are kinda lost in the sauce on this one. The attached link has the
schematic we are trying to bring together. If any of you guru's can see
whats missing, please let us know.
Thanks in advance,

2 August 2006 7:04 AM
Comox BC
I have a 277cc 2 cycle Rotax engine with point ignition and a built in
charging sytem on the flywheel. We are using this engine on a homebuilt

pls help me , i wasn't able to understand this circuit pls explain by
the way its a modified sine inverter circuit .
http://img79.imageshack.us/img79/1355/3000w12zq8.gif
Thanks in advance

I was just musing about "log amps", where they exploit the
exponential/logarithmic relationship between the current and
voltage of a PN junction.
My question is, is that always "log e", ie., "ln"? My point

I recently tested a 9V alkaline battery by measuring its open-circuit
voltage (9.0 V) and then measuring it with a car headlight lamp (R = 1
Ohm) across the terminals (4.0 V).  The lamp lit up brightly and got
warm, but from the significant voltage drop I conclude that the

Hiya, I've recently taken an interest in interfacing with floppy disk
drives just for the heck of it, and while I've learned a good amount of
stuff from much reading and a topic I posted elsewhere, there's still
something that confuses me, and since I would assume it's a more basic

i wanted to know where I could go to find a schematic or instructions
on building a 220V power supply. I have tried looking online...but, i
havent found anything besides a switching power supply(110 V / 220 V)
any help would greatly appreciated

I want to hook up a 120mm case fan to a power supply. I'm wondering if
I can just use a 12v wall wart transformer. The only thing I don't
understand, is the wattage for the fan is 4watts, but most wall warts
only output about 500-800ma.

Please bare with me, im technically a newbie to electronics, being that
im not aware of all the different circuits. However i understand
electrical theory fully and im aware of the difference between a mosfet
and a igbt and which one is appropriate for a given situation.  My

I am looking fot the math formula to figure out the voltage drop i need
and the associated resistor. such as the led uses 3 volts i have 12 i
need a resistor that will drop 9 volts. also how to figure out the size
resistor (watts).

Does anyone know about KEC 168....??
Its an infrared receiver IC , probably by Korea Electronics.

Sorry if this is the wrong newsgroup.  I'm asking because I don't know much
about electronics.
My 4+ year old laptop died recently.  (Dell Inspiron 8100.)  But the screen
is only about 1.5 years old and it still works.  It has 1600x1200 resolution

I am looking for a plug, male of hirose 18 pins I/O connector. The part
number of 18 pins I/O connector is MQ/SF178-E-18P(R)
You can see it below.
c:\temp\today\hirose\01_datasheet_IO_connector_HIROSE-MQ178_1.pdf

Yeah these questions are really hitting the fundamentals, but thanks
for anyone who helps me :)
I have a typical NPN transistor, hook a battery to the collector, add
voltage to the base connect an LED to the emitter then to ground and