PRC as a amplifier in GPS question.

On 8/11/2011 1:26 PM, John - Melb wrote:
On Nov 3, 11:11 am, terryc<newsninespam-s...@woa.com.au> wrote:

Which is? Responding to cross posting trolls?
Do us all a favour and cut this group out of your replies please.

I see the attitude around here remains unchanged.

No one on aus.electronics had an issue with Trevor posting his off-
topic anti-gun and anti-gun owner rants on aus.electronics, but get
upset at the thought of alternative viewpoint appearing.
Some of did but finally chose to ignore the idiot little prick

You don't like me playing in your wading pool, but don't have an issue
with Keefy posting his crap on aus.politics.guns solely to "annoy the
crap" out of me?

Fascinating............

--


x
X-No-Archive: Yes
 
On Nov 8, 5:29 pm, terryc <newsninespam-s...@woa.com.au> wrote:

Nothing fascinating about your stupidity, but way to go if you want to
convince people that gun owners are psychotic. Keep it up.
I don't think anything I say or do could change your opinions, they
were clearly well and truly made up well before my first post
appeared.
 
On Nov 8, 10:53 pm, terryc <newsninespam-s...@woa.com.au> wrote:

hahahahahaha TROLLED. Now do all gun owners a massive favour and STFU
about trolling idiots. It is usenet, they come with the turf. All you
are doing with this cross posting is turning people off gun owners as a
legit recreation.
What a load of bullsh**.

Reality check time, Trevor Tosspot posted his anti-gun and anti-gun
owner drivel on aus.electronics, not once, but repeatedly.

No-one told him to take it elsewhere, no one abused him, no one
challenged him.

As soon as I started posting an alternative viewpoint, some of your
lot went feral.

Not just take it somewhere else, but abuse and insults as well.

It's pretty clear that nothing I say or do is going to have any effect
on the opinions of those anti-gun and anti-gun owner wankers on
aus.electronics, their minds were well and truly made up well before I
first posted there.

Why then shouldn't I continue to "annoy the crap" out of them, Keefy
only posts here to "annoy the crap" out of me.
 
On Tue, 8 Nov 2011 13:01:25 -0800 (PST), John-Melb
<mcnamara_john@hotmail.com> wrote:

On Nov 8, 10:53 pm, terryc <newsninespam-s...@woa.com.au> wrote:

hahahahahaha TROLLED. Now do all gun owners a massive favour and STFU
about trolling idiots. It is usenet, they come with the turf. All you
are doing with this cross posting is turning people off gun owners as a
legit recreation.

What a load of bullsh**.

Reality check time, Trevor Tosspot posted his anti-gun and anti-gun
owner drivel on aus.electronics, not once, but repeatedly.

No-one told him to take it elsewhere, no one abused him, no one
challenged him.

As soon as I started posting an alternative viewpoint, some of your
lot went feral.
We don't worry about Trevor's posts on the topic because we mostly
*ignore* them, you fucking imbecile. But that would be too complicated
for you to understand, apparently.

It's pretty clear that nothing I say or do is going to have any effect
on the opinions of those anti-gun and anti-gun owner wankers on
aus.electronics, their minds were well and truly made up well before I
first posted there.
Yep, and of course, despite that you'll keep on with this campaign of
yours to discredit legitimate gun owners.

Why then shouldn't I continue to "annoy the crap" out of them, Keefy
only posts here to "annoy the crap" out of me.
Yeah. The maturity of a 12 year old. Well done.
 
On Nov 9, 9:58 am, Jeßus <n...@all.invalid> wrote:
On Tue, 8 Nov 2011 13:01:25 -0800 (PST), John-Melb





mcnamara_j...@hotmail.com> wrote:
On Nov 8, 10:53 pm, terryc <newsninespam-s...@woa.com.au> wrote:

hahahahahaha TROLLED. Now do all gun owners a massive favour and STFU
about trolling idiots. It is usenet, they come with the turf. All you
are doing with this cross posting is turning people off gun owners as a
legit recreation.

What a load of bullsh**.

Reality check time, Trevor Tosspot posted his anti-gun and anti-gun
owner drivel on aus.electronics, not once, but repeatedly.

No-one told him to take it elsewhere, no one abused him, no one
challenged him.

As soon as I started posting an alternative viewpoint, some of your
lot went feral.

We don't worry about Trevor's posts on the topic because we mostly
*ignore* them, you fucking imbecile. But that would be too complicated
for you to understand, apparently.
Bzzt sorry wrong, when first challenged about the matter, it was
strongly pointed out to me that Trevor Tosspot is one of
aus.electronics long standing and highly respected posters.
It's pretty clear that nothing I say or do is going to have any effect
on the opinions of those anti-gun and anti-gun owner wankers on
aus.electronics, their minds were well and truly made up well before I
first posted there.

Yep, and of course, despite that you'll keep on with this campaign of
yours to discredit legitimate gun owners.
Trevor's "allowed" to post his anti-gun and anti-gun owner diatribes
on aus.electronics without being abused for it, but I'm not "allowed"
to give counter argument. How is pointing out your (collectively) piss-
poor attitudes to matters like political censorship and freedom of
speech a campaign to discredit anybody except you lot.
Why then shouldn't I continue to "annoy the crap" out of them, Keefy
only posts here to "annoy the crap" out of me.

Yeah. The maturity of a 12 year old. Well done.
Don't like it, suggest you take it up with Keefy then.
 
On Nov 9, 10:20 am, terryc <newsninespam-s...@woa.com.au> wrote:
John-Melb wrote:
On Nov 8, 10:53 pm, terryc <newsninespam-s...@woa.com.au> wrote:

hahahahahaha TROLLED. Now do all gun owners a massive favour and STFU
about trolling idiots. It is usenet, they come with the turf. All you
are doing with this cross posting is turning people off gun owners as a
legit recreation.

What a load of bullsh**.

Reality check time, Trevor Tosspot posted his anti-gun and anti-gun
owner drivel on aus.electronics, not once, but repeatedly.

Which is exactly what you do; pot kettle black.
Yeah, but you didn't tell him to fuck off.

No-one told him to take it elsewhere, no one abused him, no one
challenged him.

We ignore him as sometimes he "contributes"
Yeah, hes\'s one of your long standing and highly respected posters, I
know, I was told at the time.
As soon as I started posting an alternative viewpoint, some of your
lot went feral.

Your replies are totally in the OT, trolling and abusive categories.
Not initially.

Not just take it somewhere else, but abuse and insults as well.
Pot, keetle black.
Who's got a black keetle?

It's pretty clear that nothing I say or do is going to have any effect
on the opinions of those anti-gun and anti-gun owner wankers on
aus.electronics, their minds were well and truly made up well before I
first posted there.

but the "not made up me mind yet" people are not seeing a a rational gun
owner are they?
There's not to many of them around aus.electronics, is there.
 
"Sylvia Else" <sylvia@not.here.invalid> wrote in message
news:9kb522Fa0nU1@mid.individual.net...
The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.

It probably won't happen, but when I was looking at relay specs, I found
that their ratings are usually specified as a highish reactive power, and
a much lower real power.

http://australia.rs-online.com/web/p/electromechanical-relays/1279550/

is typical, specifying in this case 300 W / 2500 VA.

I find this difficult to fathom. Imagine a purely inductive 2500VA load.
So no real power being switched, but it would arc like crazy. What am I
missing here?

Sylvia.
That's what contactors are about. They're designed for motors, ie. non unity
PF load plus startup peak. Part of your problem will be determining what the
actual load is like, as it's certain to be unspecified in hte fridge
instruction manual. Assuming you can find out, or guess the Kw rating, a
suitably rated contactor is more than likely to work OK. But since you won't
get it from HN, it may not be cheap.
 
On 9/12/2011 7:59 AM, Phil Allison wrote:
"John Fields" .

The contacts are rated at 10A for either 250VAC or 30VDC, so 250VAC *
10A = 2500VA, and 30VDC * 30A = 300W.

The higher AC voltage is permitted because the arc on opening will
quench in, at most, 1/2 cycle when the voltage across the contacts
crosses zero, while with DC through the contacts the arc will persist
until the gap between the contact is large enough to quench the arc.


** Problem being, there is simply not enough gap available to break the arc
that forms if the DC ratings are exceeded.

For the type of relay in question, a permanent arc will form with DC if the
current flow is say 10 amps and the voltage across the contacts is over 40
volts. This means there is over 400 watts of heat, mostly being dissipated
into the contacts and destroying them in a few seconds.

In the world of high powered audio amplifiers it is still common to see such
relays used to protect speakers from DC high fault currents and turn on/off
transients. In the case of former, the relay is not capable of doing the
job.
Seen that happen. Contacts weld, amp and speakers go boom.

 
"swanny"
"Phil Allison"
** Problem being, there is simply not enough gap available to break the
arc
that forms if the DC ratings are exceeded.

For the type of relay in question, a permanent arc will form with DC if
the
current flow is say 10 amps and the voltage across the contacts is over
40
volts. This means there is over 400 watts of heat, mostly being
dissipated
into the contacts and destroying them in a few seconds.

In the world of high powered audio amplifiers it is still common to see
such
relays used to protect speakers from DC high fault currents and turn
on/off
transients. In the case of former, the relay is not capable of doing the
job.

Seen that happen. Contacts weld, amp and speakers go boom.
** I have made a bit of a study of this in an attempt to find a solution.

Conclusions are:

1. There is no readily available relay capable of breaking the voltages and
currents involved if a 1000 wpc amp goes DC.

2. If you wire a changeover relay so it shorts the speaker and disconnects
the amp at the same time - chances are good the speakers will be OK, but
the relay contacts will be burnt by the resulting arc to ground. The amp
must have DC rail fuses if this is to work.

3. A large ( ie octal base ) relay with 4mm clearance contacts PLUS a
strong magnet next to the contacts CAN
work with amps up to about 400wpc. The magnet pulls at the arc and helps
break it.

4. A triac "crowbar" will also work but gives no on/off transient
suppression. The amp must be able to take a dead short without internal
failure and not have response down to subsonics or DC.




.... Phil
 
On 12/9/2011 8:48 AM, Phil Allison wrote:
"swanny"
"Phil Allison"

** Problem being, there is simply not enough gap available to break the
arc
that forms if the DC ratings are exceeded.

For the type of relay in question, a permanent arc will form with DC if
the
current flow is say 10 amps and the voltage across the contacts is over
40
volts. This means there is over 400 watts of heat, mostly being
dissipated
into the contacts and destroying them in a few seconds.

In the world of high powered audio amplifiers it is still common to see
such
relays used to protect speakers from DC high fault currents and turn
on/off
transients. In the case of former, the relay is not capable of doing the
job.

Seen that happen. Contacts weld, amp and speakers go boom.


** I have made a bit of a study of this in an attempt to find a solution.
**Mains shut down works fine in most cases, provided there is not a very
large energy storage employed. A few hundred joules should be do-able by
a serious bass driver which is normally connected to such a large amp.

--
Trevor Wilson
www.rageaudio.com.au
 
"Trevor Wilson"

** I have made a bit of a study of this in an attempt to find a
solution.


**Mains shut down works fine in most cases, provided there is not a very
large energy storage employed.

** So the AC goes off when single polarity voltage on the output passes a
threshold in voltage and time - then what?

There has to be a warning LED and an auxiliary power supply to do the AC
relay control. Ideally, it should not be possible to switch the amp back on
after DC is detected.

And there still has to be relays for de thumping.

BTW

I was after a solution that could be affordably retro-fitted to any amp.

The only time a customer is willing to pay for speaker protection to be
fitted is when they see the bill for the repair of a couple of JBL 2226s
etc.



.... Phil
 
On 12/9/2011 9:30 AM, Phil Allison wrote:
"Trevor Wilson"


** I have made a bit of a study of this in an attempt to find a
solution.


**Mains shut down works fine in most cases, provided there is not a very
large energy storage employed.


** So the AC goes off when single polarity voltage on the output passes a
threshold in voltage and time - then what?

There has to be a warning LED and an auxiliary power supply to do the AC
relay control. Ideally, it should not be possible to switch the amp back on
after DC is detected.
**Correct. I'll email you a schematic Peter Stein used 30 years ago.
Simple, cheap, reliable and highly effective. BTW: Mains switching is
accomplished by a TRIAC.

And there still has to be relays for de thumping.
**Ah, I forgot about crappy designed amps. Perhaps another relay and
appropriate sensing will be required for that purpose. In fact, perhaps
an existing design could be utilised, using a small auxiliary power
supply and an extra relay. I guess complexity and cost needs to be
weighed up against burnt speakers.

BTW

I was after a solution that could be affordably retro-fitted to any amp.
**Depends on what you call "affordable".

The only time a customer is willing to pay for speaker protection to be
fitted is when they see the bill for the repair of a couple of JBL 2226s
etc.
**Funny about that.

--
Trevor Wilson
www.rageaudio.com.au
 
On 12/9/2011 9:30 AM, Phil Allison wrote:
"Trevor Wilson"


** I have made a bit of a study of this in an attempt to find a
solution.


**Mains shut down works fine in most cases, provided there is not a very
large energy storage employed.


** So the AC goes off when single polarity voltage on the output passes a
threshold in voltage and time - then what?

There has to be a warning LED and an auxiliary power supply to do the AC
relay control. Ideally, it should not be possible to switch the amp back on
after DC is detected.

And there still has to be relays for de thumping.

BTW

I was after a solution that could be affordably retro-fitted to any amp.

The only time a customer is willing to pay for speaker protection to be
fitted is when they see the bill for the repair of a couple of JBL 2226s
etc.
**Emails to you are bouncing. Is there a trick to your email addy?

--
Trevor Wilson
www.rageaudio.com.au
 
On 9/12/2011 8:48 AM, Phil Allison wrote:
"swanny"
"Phil Allison"

** Problem being, there is simply not enough gap available to break the
arc
that forms if the DC ratings are exceeded.

For the type of relay in question, a permanent arc will form with DC if
the
current flow is say 10 amps and the voltage across the contacts is over
40
volts. This means there is over 400 watts of heat, mostly being
dissipated
into the contacts and destroying them in a few seconds.

In the world of high powered audio amplifiers it is still common to see
such
relays used to protect speakers from DC high fault currents and turn
on/off
transients. In the case of former, the relay is not capable of doing the
job.

Seen that happen. Contacts weld, amp and speakers go boom.


** I have made a bit of a study of this in an attempt to find a solution.

Conclusions are:

1. There is no readily available relay capable of breaking the voltages and
currents involved if a 1000 wpc amp goes DC.

2. If you wire a changeover relay so it shorts the speaker and disconnects
the amp at the same time - chances are good the speakers will be OK, but
the relay contacts will be burnt by the resulting arc to ground. The amp
must have DC rail fuses if this is to work.

3. A large ( ie octal base ) relay with 4mm clearance contacts PLUS a
strong magnet next to the contacts CAN
work with amps up to about 400wpc. The magnet pulls at the arc and helps
break it.

4. A triac "crowbar" will also work but gives no on/off transient
suppression. The amp must be able to take a dead short without internal
failure and not have response down to subsonics or DC.




... Phil
A big capacitor in series with the output :)
 
On 14/12/2011 3:09 AM, linnix wrote:
On Dec 13, 2:43 am, Sylvia Else<syl...@not.here.invalid> wrote:
On 13/12/2011 4:01 PM, kreed wrote:









On Dec 13, 10:40 am, Sylvia Else<syl...@not.here.invalid> wrote:
On 13/12/2011 9:23 AM, NT wrote:

On Dec 12, 5:20 am, linnix<m...@linnix.info-for.us> wrote:
On Dec 11, 5:48 pm, John Fields<jfie...@austininstruments.com> wrote:

On Sun, 11 Dec 2011 16:20:48 -0800 (PST), linnix

m...@linnix.info-for.us> wrote:
On Dec 11, 3:09 pm, John Fields<jfie...@austininstruments.com> wrote:
On Sat, 10 Dec 2011 17:19:52 -0800 (PST), linnix

m...@linnix.info-for.us> wrote:
On Dec 10, 5:06 pm, John Fields<jfie...@austininstruments.com> wrote:
You've said the defrost only happens every six hours, but for how long
is the heater energized?

knowing that will allow us to determine the duty cycle of the timer
and cause it to mimic the motor timer.

--
JF

It should be long enough to melt the ice and let the water drain off.
It can easily be programmable in a micro, at least during
development. Perhaps a 5 to 10 minutes range.

---
Thanks, but I'd prefer some real numbers from Sylvia so that I can
work up a hardware solution for her.

You don't like my numbers?

---
I don't care for conjecture, which is all you're offering.
---

Then go with the number from commerical
defrost timer.
4 minutes to 110 minutes in 2 minutes step.
4 to 12 cycles per day.

http://www.grainger.com/Grainger/PARAGON-Time-InitiatedTime-Terminate...

---
That's USD 184.75, and she's in Oz, so it'd more likely be about USD
250 before she got the part in hand.

Plus, she's got an old fridge and if went belly-up shortly after
spending the money for the defroster she'd probably wind up with a new
fridge and a homeless new defroster.
---

I would go with 2 pots + 2 A2D. adjust and time it with a micro.

---
Yeah, sure you would...

Why not post a schematic and some code showing how you'd propose to
implement your wily scheme, and I'll do the same proposing a strictly
hardware solution?

Game on?

OK, changed my mind, let do digital.

Let start with perhaps 4 buttons. Two to change cycles per day and two
to change durations. Three bits driving 138 (one of eight) to
indicate cycles (eight cycles should be plenty). Another three bits
to indicate durations such as 5,7,10,15,20,25,30 minutes. I doubt we
really want to defrost beyond 30 minutes anyway. So far, we can do it
with 10 port pins and 16 LEDs.

Just a quick first draft:

char cycle[8] = {1,2,3,4,5,6,7};
char duration[8] = {5,7,10,15,20,25,30};
int c_idx;
int d_idx;

while(1)
{
if(port(c_up))
c_idx++;
if(port(c_dn))
c_idx--;
if(port(d_up))
d_idx++;
if(port(d_dn))
d_idx--;

defrost_on();
delay(d_idx);
defrost_off();

delay_hrs(24/cycle[c_idx]);

}

...

Its a better idea to stop defrost cycle when the exchanger temp rises
above freezing. Otherwie you're wasting energy, and at some point the
machine will likely ice up.

NT

The 'standard' self-defrost implementation has an additional thermostat
on the cooling element, which trips open when the element reaches some
predetermined temperature (11C on mine), and closes again at some lower
temperature (0C on mine).

11C seems rather high, but I suppose it's intended to ensure that the
entire element has defrosted, not just the part near the thermostat. It
also means the thermostat need not be that accurate.

Switching the cooling back on immediately after the thermostat trips off
seems attractive, to avoid defrosting the stuff in the freezer, but I
have some misgivings about the impact on the compressor of starting when
the element is that warm.

It's not clear to me why the machine would ice up if the defrost cycle
is left running too long.

Sylvia.

You could design a defrost system like was on the New Inventors last
year.
IIRC a resistive strip was placed in the freezer, a known voltage
passed through it periodically
and the resistance of it measured (heat causes resistance to rise, and
the more frost/ice formed on the strip
the longer it took to heat up and resistance to rise) and turn on the
defrost system only when
sufficient ice was detected.

I suppose it depends what one is trying to achieve. Clearly, it's
wasteful of energy to heat up, and then cool, an element that doesn't
have much ice on it.

On the other hand, keeping it that way means that the defrost cycle
doesn't have to take long, which is helpful is one's primary goal is to
keep the freezer compartment below a certain temperature.

Sylvia.

Sound like we should wire the whole fridge with sensors. But that's
fine, thermistors are cheap. PIC32 can handle up to 16 analog
channels.
Bad idea. All that would happen would be that you'd discover that the
distribution of emperatures in the fridge are not what you'd like them
to be, but that since all you have is on/off switches for the
compressor, fan, and defrost heater, there's little you can do about it.

But if you're also adding some mechanically operated vents, and some
additional fans, then now you're talking.

Sylvia.
 
On Dec 15, 4:42 pm, John Fields <jfie...@austininstruments.com> wrote:
On Thu, 15 Dec 2011 13:46:46 -0800 (PST), linnix

m...@linnix.info-for.us> wrote:
Yes, I hate BASIC dialect of English.

---
Why would you hate BASIC and what do you mean by "dialect of English"?
BASIC force me to think differently with

reg &= ~BIT5;
reg |= BIT7 | BIT 4 | BIT 2;
reg >>= 4;

Run through a good compiler, the object code of any programming
language should be the same.
---

I only speak C.

---
More's the pity.

--
JF
 
On Dec 25, 9:27 pm, atec77 <ate...@hotmail.com> wrote:
On 25/12/2011 8:02 PM, Brad wrote:

On Sunday, December 25, 2011 6:53:32 PM UTC+11, fuckeaded Graham Cooper vomited:

shite snipped

Agreed, you are not a rational normal logical person. No other explanation is required.

If you ignore that sucked in prune head the rest of us wont be subjected
to it's brand of shite

  OK ??

OK aus.tv!

You have chosen to follow Peter Bow-Ditches path and mock and abuse
anyone who challenges their status quo.

Look what happened to him!

http://camaffiliate.com/media/PETER-BOW-DITCH.jpg

This WAS your last chance to be reasonable, none of you can ever enjoy
the fruits of religion ever!

GOOD BYE you ignorant Pigs AUS.TV. And that includes all the lurkers
who silently supported this mob of aus.tv trolls! Try logging into
CyberSpace 2014... you are all banished to low-techs now!

And all the other shit-stirring aus groups... YOU'RE ALL EXILED FROM
THE NEW INTERNET

HERC
 
On Sun, 25 Dec 2011 11:53:48 -0800 (PST), Graham Cooper
<grahamcooper7@gmail.com> wrote:

On Dec 25, 9:27 pm, atec77 <ate...@hotmail.com> wrote:
On 25/12/2011 8:02 PM, Brad wrote:

On Sunday, December 25, 2011 6:53:32 PM UTC+11, fuckeaded Graham Cooper vomited:

shite snipped

Agreed, you are not a rational normal logical person. No other explanation is required.

If you ignore that sucked in prune head the rest of us wont be subjected
to it's brand of shite

  OK ??



OK aus.tv!

You have chosen to follow Peter Bow-Ditches path and mock and abuse
anyone who challenges their status quo.

Look what happened to him!

http://camaffiliate.com/media/PETER-BOW-DITCH.jpg

This WAS your last chance to be reasonable, none of you can ever enjoy
the fruits of religion ever!

GOOD BYE you ignorant Pigs AUS.TV. And that includes all the lurkers
who silently supported this mob of aus.tv trolls! Try logging into
CyberSpace 2014... you are all banished to low-techs now!

And all the other shit-stirring aus groups... YOU'RE ALL EXILED FROM
THE NEW INTERNET

HERC

Bwahahahahahahaha!

Whatta Maroon!

Shill #2
--
Ears on the loon go round and round, round and round, round and round...
theobviousgcashman
 
Graham Cooper <grahamcooper7@gmail.com> wrote:

And all the other shit-stirring aus groups... YOU'RE ALL EXILED FROM
THE NEW INTERNET
I'm going to miss you all after the exile ruling comes into effect.
Goodbye, everyone, it was nice knowing you. Maybe we can meet up in
real life somewhere, perhaps at a pub.

--
Peter Bowditch aa #2243
The Millenium Project http://www.ratbags.com/rsoles
To email me use my first name only at ratbags.com
I'm @RatbagsDotCom on Twitter
 
On Dec 26, 3:45 pm, Peter Bowditch <myfirstn...@ratbags.com> wrote:
Graham Cooper <grahamcoop...@gmail.com> wrote:
And all the other shit-stirring aus groups...  YOU'RE ALL EXILED FROM
THE NEW INTERNET

I'm going to miss you all after the exile ruling comes into effect.
Goodbye, everyone, it was nice knowing you. Maybe we can meet up in
real life somewhere, perhaps at a pub.

Yeh Demon! Last time I gave Aus Skeptics my address YOU sent the
police around for another decade of kook bashing.

The 1st time too! 4 Macintosh Street = FOR APPLE on my application
form!

Remember how surprised you all were how quickly the police tracked me
down!

They must have done their training at Dominoes Pizza!

http://camaffiliate.com/media/21122011338.jpg
http://camaffiliate.com/media/21122011339.jpg
http://camaffiliate.com/media/PETER-BOW-DITCH.jpg

So much for ADAM AND EVE in KINGS BEACH QUEENSLAND!

Oh wait! YOU CAN DO THAT TOOOOO!

Herc
 

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