Electronics Forum / Basics / July 2005

I have a multipart question for purposes of a self-tutorial.
Some of this "esoteric" audio information can drive you nuts and often
times, is contradictory.....hence, my questions.
Ok....so I have this little USB DAC chip that I've breadboarded......the

I am trying to use CCM1620CSL(a 44780-based LCD module) and that is
the first LCD i am trying my hands on.
I have interfaced the LCD to a PIC and till now, whatever program I
run, the result is 16 black boxes on the 2nd line of LCD (it's a 16x2

I want to use my TV's built in speakers as the center channel
for my old ProLogic surround. My TV has stereo audio inputs,
my ProLogic receiver/amp has only amplified center outputs
in mono. I had thought about trying to take my TV apart and

I have a problem.
Just completed a basic LM317 PSU for my PMR (6.5v 200ma) two caps and a
couple or resistors etc.
The PMR and charger/PSU feed an audio amp for field event type stuff.

Hi, I was wondering if anyone could help me with a curious question.  How
would one go about measuring the impedance of a wall socket?  Assuming it is
120V, of course.  I'm not just looking for a formula but rather to
understand the concept.  Any websites or other resources would be

I have a DPDT toggle switch, and I like to give two inputs to it
(AC and DC) .
by toggling the switch to AC I like to get AC out put, and toggling to
DC I like to get DC out put.( one at a time).

http://chrispol.ath.cx:8080/switch.jpg
would this be the proper circuit to optically source current to a heavy
load?
Thanks

    --Here's the situation: I've got a small vehicle that uses a 6v
battery for starting. But I need a 12-v supply to run some auxiliary
lighting stuff. What I'd like to do is add a second 6-v battery in
parallel with the first one, so that the engine will "see" 6v when it's

I have recently started working on application of SiC technology in
VLSI application, but unfortunately I couldn't find much literature
avilable on internet. It would be grateful if any one can help me out
on finding them or giving me guidence.

What's the best timer chip to pulse multiple pen laser like this http://www.onewithall.net/laser_pulse.gif 
Is it possible just to use one IC chip?  If so anyone have an example
TIA

Just when I think I'm advancing as an engineer I come across something
that is simple in theory but completely stumps me.  I am going through
a product design review.  I am stuck on a comment a senior design
engineer made.

I am looking for a place that does cheap small run pcb's (5-10).

Hi Guys, I'm working on a project that is supposed to encourage kids to
ride a stationary bike for three minutes. The plan is to have the rider
hit a button when they get on the bike and that sets a series of timers
going each one triggering a light or embedded sound bit encouraging ...

Can someone tell me if this a good deal and of reasonable quality for a
hobbiest?
http://www.megaproductions.net/Soldering_Iron1.htm

I'm needing to put together a series of timers. Plan is to have6 timers
all triggered at the same time. The first should time out and complete
a circuit at 30 seconds, the second at 60 seconds, 60, 120, 150, 180
Can anybody give me a basic circuit and values of the required