Electronics Forum / Basics / January 2007

I want to take this time to thank those who responded to my inquiry
concerning the placement of batteries in a parallel circuit; the
situation concerns my scooter, which I desperately need in order to
navigate my little world. Some of you may recall my name, as I dealt

Two recent projects involved industrial sensors that required temperature
compensation. The budget dictated thermistors.
The sensor's temperature response was linear, and of course thermistors are
very non-linear.

Regarding the following schematic:
http://tinypic.com/view/?pic=2ecnm94
I've seen many schematics that have suggested that the resistor in the
non-inverting input should be equal to the parallel equivalent of the

Let's say I have two mono sources that will be outputted as a stereo
signal to a headphone. If the mono sources pass thru two simple opamp
configured as inverting amplifiers, how do I control the amplitude
level of both mono sources simultaneoulsy? Is there a potentiometer

I'm interested in RF and RFIDs, as well as electromagnetic fields
(especially the generation, measurement, and detection thereof).
Think you could help me out?
Also appreciated would be scrap electronic components, as I'm fairly

I have been studying about using a transistor as a switch at:
http://www.kpsec.freeuk.com/trancirc.htm
I built a npn transistor switch on breadboard using a MPSA06
(HFE=100min, FT = 100MHz).

Happy New Year!
What happens if I connect the outputs of four opamps configured as
voltage followers?
I am not sure if I'm applying the right analysis, but if I use

Need help designing a 12vdc  circuit interrupt using a mosfet. Will
probably need to handle 10 amps. Would like to be able to adjust the
duty cycle. Any suggestions would be great.

I am trying to simulate a simple opamp circuit with Linear's LT Spice
simulator. The circuit is  simply a single supply opamp, the minus
input connected to 0.5V and the plus input connect to a 1V sine wave.
The output is connected to ground by 1K R.

Is there a reason why different websites list different
signal states on some parallel port pins? Are some just
wrong, or were there two types of parallel ports for
PC's at one time?

Hello, I just finished creating a circuit, it's a drum machine, but
I've done the whole thing on a solderless breadboard.  I was wondering
if anybody could give me any tips on how I could go about transferring
my design onto a PCB.  If anyone could reccomend any software or such

How are the Instek DSOs, in particular the "portables" like GDS-2064,
in comparison to comparable Tek 'scopes like the TDS2004B?  Tek has
always had a good reputation, but the Instek is considerably cheaper.
Is it the name you're paying for, or are the Tektronix models really

I am building a unit that will have a small 9v battery for power. I
will put a voltage comparator and it will activate a led to warn for a
low voltage battery. Iwould like to know at what voltage dos the
battery need to be change, when is it dead ? is it 7.5 v ? or 8?....

This is my first attempt to write to eeprom
using a pic18f2455. Obviously it isn't
working. ;)
Most of it is straight out of the datasheet;

If you recognize this button and knows where to buy it, please email
tia.gao@gmail.com.  We will pay $20 for the first correct answer.
These buttons are hermetically sealed, about the size of a quarter and
ultra-flat.