Electronics Forum / Basics / January 2007

                 It is seen that the capacitances in parallel add up.
the equations are
   Q= Q1/V +Q2/ V
     = (Q1+Q2)/V

A portable DVD player originaly used a 9 volt 2 amp charger for its
battery. Can a 9 volt 1 Amp charger be used instead. How will this
effect the charging or battery? Thanks.JB

I am looking for the instructional leaflet for this.
I have had no success with Googling or at the manufacturers website.
Any help will be greatly appreciated.

I'm using an analog 4066 switch in an application where the input is an
audio signal being passed to a speaker, I'm going to be switching the
switch on and off the fastest.... maybe 5 times per second.  My
question is, do I need to worry about debouncing this switch?  Or is

What considerations do I need to take when connecting multiple
microphones to a pre-amp? Can I even do that?
Just by looking at it, I know that I'm paralleling multiple
capacitances. This will probably change the frequency response of the

I have a 4.5V power supply, and I need make a 1.5 V bypass.
How can I do this ?
Regards.

I am running a laser diode off a varialbe pulsed current source with a
variable current output and pulse width. I want to run my laser at 1mA or
less, however the current driver is designed for high power current
applications and on switch on with no selected current output it ...

When buying a surge protector, should brand matter or are all brands
basically the same quality? I'm aware that I should be checking things
such as clamping voltage, energy absorption/dissipation, and response
time. But there seems to be big price differences among some brands and

I've been trying to rig up some motors (both DC and stepper) and
solenoids to a PC's parallel port.  I seem to be running into two
problems:
1) My buffering IC (between the parallel port and the devices) cannot

I am looking for a way to create a module that allows me to simply
switch something(on/off) remotely. I will be installing this in a car
and it seems that probably the best way to do this is a GSM module of
some kind. Any pointers on how to get started finding components or

I want to electrocute criminals and sinners myself, because
the justice system is corrupt as hell.
So, HOW can I build my own electric chair to kill those who
are harmful to society???

Hey all;
In the schem below, there are 4 inverters which may send a logic high to
input 2 of the latch at any time, possibly at the same time. I have a
similar circuit in a switching unit I have built, and figured the diodes

For those of you who 'chimed in' for me with regard to my scooter and
the placement of another set of batteries, I have encountered a
problem: charging. I have (had) a 12 volt charger that worked very
well; that is, it worked until I attempted to place the charger on the

Just wondering if anyone knows the weight of these batteries?
AAA 900mAH
AA 2500mAH
or will they vary between manufacturers?

For a few years now I've been lighting our bedroom mainly with white
Christmas lights strung across the ceiling.  They've gotten pretty dim
and burned out by now, and need replacing.  But they seem to heat the
room up quite a bit in summer, plus I'm getting somewhat bored with