P
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
The ignition switch turns the car off, correct? So, feed the ignitionhttp://i8.photobucket.com/albums/a23/tcw_fort/carparts/wiringcutoffswitch.jpg
What matters for voltage drop is not the 10.5-14.6 voltage, but theLooking at your proposal, if I have a 14gauge wire carrying up to 14.6
volts (alternator output when charging) and as low as 10.5 volts (low
battery power until alt spins up. but enough to fire the ignition
system), what would be the best gauge wire, and method of connecting
it to limit voltage drop over 30 feet (15feet one way) to a minimum.
If I'm going to switch a power source for sensors, I need to be
certain that voltage drop is as minimal as possible otherwise sensor
readings may be mis-interpreted by the EEC-IV processor which monitors
the sensors.
"Bob Monsen"
"Phil Allison"
One of the nice things about AM, and the reason they use it for
aviation, is that power wins. If two signals are colliding, the more
powerful one will always be heard.
** That is how FM behaves - ie the "capture effect".
AM does no such thing - " colliding " signals simply combine in the
receiver and are heard together.
Weak signals are heard in the background of strong ones.
Thanks for the clarification. However, I'm curious about this.
** Firstly - I am very impressed that you accepted my comments in the
spirit they were intended.
A rarity on usenet - my congrats.
An FM signal is really just a frequency shift on the carrier. As I
understand it, the transmitted signal is the carrier frequency shifted in
proportion to the amplitude of the sound that will get transmitted (for
mono).
So, given two transmitters on the same frequency, you end up with two
varying carriers. If your receiver is just receiving both signals, mixing
them down to a lower frequency, detecting the shift, and converting that
into an amplitude, the detector must be doing this locking on. Do you
know how it works? How does it lock on rather than just outputting a
mess?
** Capture effect is almost entirly due to the " limiting " that occurs
in the IF amplifier stages.
Unlike AM, the IF stages of an FM receiver are normally operated very
heavily into overload ( ie gross amplitude clipping ) so the weaker of two
( IF frequency FM signals ) is completely over-whelmed by the stronger
e - which them becomes the only signal present at the FM detector.
There is even a Wiki about it:
http://en.wikipedia.org/wiki/Capture_effect
This feature was seen as a BAD idea for aircraft radio comms - it being
preferable to have something more like a telephone party line, so the
weaker voice could still be heard and even if not read clearly, the pilot
or ground controller could ask for a repeat of the message.
This got screwed up once at Tenerife and two jumbo collided as a result.
http://en.wikipedia.org/wiki/Tenerife_disaster#Communication_misunderstandings
...... Phil
"Bob Monsen"
"Phil Allison"
One of the nice things about AM, and the reason they use it for
aviation, is that power wins. If two signals are colliding, the more
powerful one will always be heard.
** That is how FM behaves - ie the "capture effect".
AM does no such thing - " colliding " signals simply combine in the
receiver and are heard together.
Weak signals are heard in the background of strong ones.
Thanks for the clarification. However, I'm curious about this.
** Firstly - I am very impressed that you accepted my comments in the
spirit they were intended.
A rarity on usenet - my congrats.
An FM signal is really just a frequency shift on the carrier. As I
understand it, the transmitted signal is the carrier frequency shifted in
proportion to the amplitude of the sound that will get transmitted (for
mono).
So, given two transmitters on the same frequency, you end up with two
varying carriers. If your receiver is just receiving both signals, mixing
them down to a lower frequency, detecting the shift, and converting that
into an amplitude, the detector must be doing this locking on. Do you
know how it works? How does it lock on rather than just outputting a
mess?
** Capture effect is almost entirly due to the " limiting " that occurs
in the IF amplifier stages.
Unlike AM, the IF stages of an FM receiver are normally operated very
heavily into overload ( ie gross amplitude clipping ) so the weaker of two
( IF frequency FM signals ) is completely over-whelmed by the stronger
e - which them becomes the only signal present at the FM detector.
There is even a Wiki about it:
http://en.wikipedia.org/wiki/Capture_effect
This feature was seen as a BAD idea for aircraft radio comms - it being
preferable to have something more like a telephone party line, so the
weaker voice could still be heard and even if not read clearly, the pilot
or ground controller could ask for a repeat of the message.
This got screwed up once at Tenerife and two jumbo collided as a result.
http://en.wikipedia.org/wiki/Tenerife_disaster#Communication_misunderstandings
...... Phil
Set Rs to 0 and then do your calculations.I've found this circuit
http://img521.imageshack.us/img521/8127/fasdgspi6.jpg
but i don't konw how to obtain this result
http://img293.imageshack.us/img293/5995/isggsdgps5.jpg
with Rs<<Rl and Req=RjRl/(Rl+Rj)
How can i obtain Pout?
thanks
Set Rs to 0 and then do your calculations.I've found this circuit
http://img521.imageshack.us/img521/8127/fasdgspi6.jpg
but i don't konw how to obtain this result
http://img293.imageshack.us/img293/5995/isggsdgps5.jpg
with Rs<<Rl and Req=RjRl/(Rl+Rj)
How can i obtain Pout?
thanks
NTE is for lazy folk who don't bother to compare datasheets and instead want"Sky King" <aaron_stansbury@yahoo.com> wrote in message
news:f369c5c2-3e20-4555-872b-5a413cb0a9ef@x41g2000hsb.googlegroups.com...
Is there a web site that will cross reference chip numbers? I have
some older designs I would like to build, but the chips they list are
no longer made. Any help will be helpfull.
Thank you,
Sky King
The nte site has one, but I wouldn't buy their parts, since they are so
expensive.
http://www.nteinc.com/
Regards,
Bob Monsen
NTE is for lazy folk who don't bother to compare datasheets and instead want"Sky King" <aaron_stansbury@yahoo.com> wrote in message
news:f369c5c2-3e20-4555-872b-5a413cb0a9ef@x41g2000hsb.googlegroups.com...
Is there a web site that will cross reference chip numbers? I have
some older designs I would like to build, but the chips they list are
no longer made. Any help will be helpfull.
Thank you,
Sky King
The nte site has one, but I wouldn't buy their parts, since they are so
expensive.
http://www.nteinc.com/
Regards,
Bob Monsen
Just wire it to a lamp dimmer.Sorry for such a simple question, but I've got a few 120mm
240V .125A (?30W) axial fans like a bigger version of the case
cooling fans in a computer.
I've set one up in a box with a large truck air filter so I can run it
24/7 to remove dust from my house atmosphere. At the moment, the
aircons and computers do it
Unfortunately these fans are a little too energy hungry and noisy.
What are my options for slowing them down a tad?
I thought of adding a resistance in line, but this would only
dissipate heat -- not lost in Winter, but a waste of money in Summer.
Then I thought about running two of these in series.
Is there any cheap and cheerful way to cut down on these over
enthusiastic, but otherwise great little ball bearing fans?
Thanks, jack
Just wire it to a lamp dimmer.Sorry for such a simple question, but I've got a few 120mm
240V .125A (?30W) axial fans like a bigger version of the case
cooling fans in a computer.
I've set one up in a box with a large truck air filter so I can run it
24/7 to remove dust from my house atmosphere. At the moment, the
aircons and computers do it
Unfortunately these fans are a little too energy hungry and noisy.
What are my options for slowing them down a tad?
I thought of adding a resistance in line, but this would only
dissipate heat -- not lost in Winter, but a waste of money in Summer.
Then I thought about running two of these in series.
Is there any cheap and cheerful way to cut down on these over
enthusiastic, but otherwise great little ball bearing fans?
Thanks, jack
What is the best approach to generate a delayed output from a trigger
input to a PIC microcontroller? The idea is to have a constant known
time from trigger input to output, so I don't want to poll the logic
level on some pin due to the jitter that would occur. Thought about
using the comparator module to generate an interrupt, but it seems
complicated setting and clearing all the various bits and reference
levels.
At some point the voltage will be to low to start the motor, it will runOn Tue, 22 Apr 2008 14:25:24 +0800, spamfree@spam.heaven wrote:
On Mon, 21 Apr 2008 23:47:42 +0800, spamfree@spam.heaven wrote:
I've read that a transformer would be OK.
I see a cheapie 36V that would suit.
What speed would the fan likely do (fraction of full speed) at 36V?
Perhaps around half speed, if the curve I/rpm is logarithmic?
Could someone check my calculation, please?
The motor draws 125mA at 240V.
So at 36V, it should draw roughly 36/240 x 125 = 18.75 mA
The VA (~Watts) here will be 18.75 x 36/1000 = 0.675 W
Which will cost me ~ $1 per annum to run.
What would be the approximate efficiency of the transformer?
Cheers, jack
Assuming the trigger not to be synchronous with the PICs clock, you willWhat is the best approach to generate a delayed output from a trigger
input to a PIC microcontroller? The idea is to have a constant known
time from trigger input to output, so I don't want to poll the logic
level on some pin due to the jitter that would occur. Thought about
using the comparator module to generate an interrupt, but it seems
complicated setting and clearing all the various bits and reference
levels.
Is there an easier way?
-Bill
406 Mhz which is ( I believe ) in a protected area of the spectrum. I do"Don Bowey" <dbowey@comcast.net> wrote in message
news:C42E653D.B6601%dbowey@comcast.net...
On 4/18/08 11:25 AM, in article lI5Oj.4682$iK6.2220@nlpi069.nbdc.sbc.com,
"Joerg" <notthisjoergsch@removethispacbell.net> wrote:
Don Bowey wrote:
On 4/18/08 8:16 AM, in article fuae44$6tg$1@dns3.cae.ca, "Claude"
claudec@cae.com> wrote:
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:cJMNj.6968$GE1.6102@nlpi061.nbdc.sbc.com...
Michael Black wrote:
On Wed, 16 Apr 2008, Bob Eld wrote:
"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com...
Hi all
If I change the tank circuit components (reduce the capacitance
and
inductance) and change the transistors to appropriate VHF ones,
will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?
http://www.electronics-lab.com/projects/rf/006/index.html
Thanks
Shelton.
Not likely. I doubt you'd ever get that circuit to work at VHF
frequencies
no matter what you did with the resonant circuit portion. There are
many
problems including wrong impedances for the various parasitic
capacitances.
Secondly air traffic stuff is FM I believe.
Military may use FM, I don't know, but airplane related
communication is
unique in that it does use actual AM.
A project that saw publication a number of times in the old days
took
advantage of that, a "crystal radio" that tuned VHF. It was nothing
more than a tuned circuit and a diode detector feeding an earphone,
not
sensitive but useful near airports and since it didn't radiate
anything,
even useable (though maybe not legally) on an actual airplane.
The description of the circuit says it's a regen receiver, and those
were never popular at VHF, I'm assuming instability came into play.
You did see superregen receivers there. Either type will radiate,
and
that's not a good thing in the aircraft band.
Yes, and then you'd quickly have visitors coming with vehicles
bearing
government license plates. A regen-receiver is most definitely not a
good
idea in the aircraft band.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
Quite correct, it is most likely jail time where you will have hours
and
hours of fun designing electronics such as movement alarms
that will detect the proximity of "fellow inmates" . Just swearing on
an ATC
frequency will net you a $2,500 fine in Canada, I can't even imagine
what
they would do to you if you jammed one of their frequencies.
Claude
Montreal
One of you naysayers should estimate the amount of radiated energy from
a
typical regen receiver.
Also, what is the distance from the intended regen location to the
airport,
and what would you imagine the comparative strengths would be of the
regen
signal and air traffic signals at air traffic receivers?
The regen receiver radiated signal would be lost in the noise.
The other party to air traffic communication are aircraft. Those happen
to roam about quite a bit
Seriously, disregarding the airstrip that's almost next to the office
here we are also roughly in the flight path for Mather Field. Altitude
above our building maybe 1500ft, give or take. If Fedex, DHL and other
pilots would report some weird shhhhht noise everytime they pass a
certain spot, guess what would happen?
I doubt that at 1500 feet the signal from a regen receiver would break
the
squelch.
If a malfunctioning DTT set-top box can radiate enough to set off a SARSAT
and call out air-sea rescue, I have little doubt what a regen receiver is
capable of if it goes anywhere near the relevant frequency, especially if
connected to an antenna cut for one of the aero bands. See
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/01/15/ufreeview.xml&sSheet=/portal/2006/01/15/ixportaltop.html
I wonder what they charge for vexatious call-outs!
Chris
Which probably explains why the new 406 EPIRB transmits to the satellite at
Bret Cahill wrote:
:10X More Efficient
Cite your sources for 920% efficiency.
Cite where you think he said that. It's not in this thread.
The losses in electrical transmission have increased from about 5% to 9.5%Is there some low frequency radiation or hysterisis loss or what?
The losses in electrical transmission have increased from about 5% to 9.5%Is there some low frequency radiation or hysterisis loss or what?
The OP's question is an absurd troll.
Like you.
Are modern "scientists" really this dense? Ten times efficient isn't
920%! What you must have just graduated from a "modern" high school?
Dig. If standard transmission is 92% efficient, then that means there
is 8% of the energy lost. TWICE as efficient would only have 4% of the
energy lost or would be 96%. The interested student can take it from
there...