sci.electronics.design Google Group

Re: Who's Got the Brightest LED? November 19, 2008

2008-11-20T09:10:42Z

I do not think they aer intelligent YET.

Re: CMOS Xtal OSC op voltage

2008-11-20T09:09:52Z

Minimum reliable operating voltage appears to be 2.5V and operation
may be more stable and accurate.

Re: Low Voltage Cutout

2008-11-20T08:59:29Z

I'd go for a circuit with an adjustable undervoltage trip point.
Once power returns,the charging voltage is sensed and the circuit
returns to normal.
I propose one comparator set up with hysteresis, one V reference and a
transistor to drive the relay..
Alternatively a DTL circuit could be made up.
Extra relay contacts can sometimes put to use for circuit function.

Re: Log-Periodic Antenna Design

2008-11-20T08:53:28Z

Why don't you sell your house and move to a place next to the TV
transmitter station. You will only need a piece of wire then.
Or the bare finger.
Must be wet, of course.
w.

Low Voltage Cutout

2008-11-20T08:05:19Z

Hi
I have an access control system running off a float charged battery.
If there is a power outage of +-8 Hours, the battery drops to a level
lower than the access-control system can handle, and then it does not
recognise the tags (the readers actually lockup, but the maglocks stay
locked).
I was thinking of putting a 9v zener diode on the battery, running a

DISNEY VISA CARD

2008-11-20T07:24:31Z

DISNEY VISA CARD
[link]

Re: Log-Periodic Antenna Design

2008-11-20T06:53:28Z

Hi Rich,
Someone else has already provided the translation, so that will take
care of some of the wholes in data entry and reading.
Tau is related to the shape of what you call the pyramid, or more
actually to the angle of the taper. This defines the smoothness of
matching across the span of frequencies you entered into the program.

Re: charging 10 cell nimh pack 6 cells at a time?

2008-11-20T06:40:18Z

Why not experiment with all your ideas? Then you can
decide which you like best. :-)
Ed

Re: Log-Periodic Antenna Design

2008-11-20T06:05:19Z

OK brother, you may not be what I accuse you of ...
But darn, the antenna you bought was designed with certain parameters in
mind ... I would seriously doubt you are going to vastly increase
performance with the route(s) you have described here ...
Sorry if I made a joke. But, my advise to you would be, if you saved

Re: Who's Got the Brightest LED? November 19, 2008

2008-11-20T05:40:30Z

Before you dog on phlatlight, Jim, remember its a MIT project gone
commercial.
Its also one of the few manufacturers I've looked at that can meet its
specs. The inherent 60' beam width makes it useful, or am I the only
one here who has ever found out how frustrating it is to try to make
lambertian collection optics. Yeah, Osram has a roomlight. Try to

Re: Pwr suppley Problem

2008-11-20T04:17:44Z

On Wed, 19 Nov 2008 19:54:21 -0800 (PST), scott93727g <eb3...@aol.com>
wrote:
Sorry.. I'm a very visual person.. Schematic please..
Perhaps see:
[link]
Page 14 has an example of paralleling regulators.
But what bugs me, why parallel regulators???
I'm inclined to get the same function by paralleling transistors, use

Re: Who's Got the Brightest LED? November 19, 2008

2008-11-20T04:04:21Z

On Wed, 19 Nov 2008 23:05:07 +0000, Eeyore
Discussion is open to anything freaky bright..
Whoever is leading with the brightest colour or has the highest
luminous efficacy.
Let's say the most amount of light from some chunk of semiconducting
material. Something compact, point like and has high light output.

Financial meltdown

2008-11-20T03:58:01Z

Take a peek at this if this works:
Blame Cheap money-Asian savings-Greedy banker-Deregulation (a prime
suspect) for 2008 crash-A short history of modern finance-E

Pwr suppley Problem

2008-11-20T03:54:21Z

Pwr suppley Problem
I made a power supply with 3 paralelled LM338 Regulators in paralell
(24V 12A trans), with 2 paralelled 20A rectifirs, worked great for 1
week, then all of a sudden, output dropped to 2 amps max (from 15A), ,
all componed seem to check out ok, getting full current out of filter
caaps past rectifiers, any ideas, tried substituting a good regulater,

Re: I think I'm going to be sick...

2008-11-20T03:48:44Z

You used the term "drove the market". I am suggesting that the F & F
problem may have been the lit match but it wasn't the pool of
gasoline. There is no doubt that F & F were part of the problem but
not the reason that the entire credit markets were knocked for a loop.
But you see I say they didn't "drive the market" nor were they a big