PRC as a amplifier in GPS question.

[The real Andy]

<SNIP>

Can someone post a copy?? Or if one is not keen to type it, perhaps I could
get a scanned copy emailed to a.pearson at optusnet dot com dot au. I will
also check the antispam 'reply to' address that I use for usenet. I would
love to read what he says. Considering that SC is stuck in the dim dark ages
of circuit design, i'm surprised that SC has even discovered usenet.

 

[Brian Goldsmith]

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote


Can someone post a copy?? Or if one is not keen to type it, perhaps I
could
get a scanned copy emailed to a.pearson at optusnet dot com dot au.


*** Buy the bloody thing ,you effing cheapskate.
Brian Goldsmith.

 

[William P.N. Smith]

"Duane C. Johnson" <redrok@redrok.com> wrote:

Duane C. Johnson wrote:
I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif

I chose a BS107 small MOSFET for it's very low gate
voltage. There are better MOSFETs but that's the one I had.

How would one select a MOSFET with a gate voltage under 5 volts for
full saturation and a peak current rating of about an amp?

I know how FETs work, but haven't used them, and don't really know how
to select them...

Thanks!

--
William Smith wpns@compusmiths.com N1JBJ@amsat.org
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[Duane C. Johnson]

Hi William:

"William P.N. Smith" <wpns@compusmiths.com> wrote:

"Duane C. Johnson" <redrok@redrok.com> wrote:
Duane C. Johnson wrote:
I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif

I chose a BS107 small MOSFET for it's very low gate
voltage. There are better MOSFETs but that's the one I had.

How would one select a MOSFET with a gate voltage
under 5 volts for full saturation and a peak current
rating of about an amp?

In my circuit, this was not needed. That's why the use
if the TO-92 packaged BS107. It is used to bootstrap
the voltage up to a higher operating range needed for
the "logic" gate power MOSFET.

I know how FETs work, but haven't used them, and don't
really know how to select them...

Good engineering practice would suggest that the gate on
a MOSFET be driven just as the manufacturers says.

However we can often go outside the suggestions in
special applications. In this case the IRLZ44 is a
50A transistor. I also know the gate threshold voltage
is about 2 volts. At 2.5 volts the transistor is
pretty well turned on.

Of course, there is nothing so instructive as some parts
and a plug board with which to experiment. Some of the
best AhHa moments happen when you just try something
ant then understand the outcome.

Thanks!

Duane

--
Home of the $35 Solar Tracker Receiver
http://www.redrok.com/electron.htm#led3X [*]
Powered by \ \ \ //|
Thermonuclear Solar Energy from the Sun / |
Energy (the SUN) \ \ \ / / |
Red Rock Energy \ \ / / |
Duane C. Johnson Designer \ \ / \ / |
1825 Florence St Heliostat,Control,& Mounts |
White Bear Lake, Minnesota === \ / \ |
USA 55110-3364 === \ |
(651)426-4766 use Courier New Font \ |
redrok@redrok.com (my email: address) \ |
http://www.redrok.com (Web site) ===

 

[The real Andy]

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f4f3357$0$10357$afc38c87@news.optusnet.com.au...

"Brian Goldsmith" <brian.goldsmith@nospamecho1.com.au> wrote in message
news:BKE3b.70538$bo1.51854@news-server.bigpond.net.au...

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote


Can someone post a copy?? Or if one is not keen to type it, perhaps I
could
get a scanned copy emailed to a.pearson at optusnet dot com dot au.


*** Buy the bloody thing ,you effing cheapskate.
Brian Goldsmith.



** Cheapskate was my word too - when I emailed him a scan.



.................... Phil

Thanks Phil. I'd buy it, but it would have taken me two weeks. By then I
would have forgoten...

 

[Mark Fergerson]

Duane C. Johnson wrote:

Hi Mark;

Hi back, and thanks for all the explications;

Mark Fergerson <mfergerson1@cox.net> wrote:

IIRC in the older version there was no transformer, just
a boost coil like L1; but in the newer one you seem to have
it connected as sort of a hybrid balun/autotransformer
thingie. BTW it's a standard small audio type, yes?

My cad program doesn't have very many choices
for transformer symbols.

Don't feel bad; if I bother to do any schematizing on my
puter I use a symbol font in MSPaint.

I'm so old I usually use pencil and graph paper.

This transformer is a large ferrite core with a few
turns on the primary. The secondary is determined
experimentally.

Um, "large"? I was kinda hoping to keep this small. Time
to get out the bits 'n' pieces and see how small "large" can
be made.

The inductor was a small ferrite core.

Got lots of those.

Anyway my confusion was how the thing started. I forgot
there'd be _some_ voltage on the NiCd. Silly me.


True, I just wanted to guarantee that the thing would
even with a totally dead NiCd.

There seems to be some disagreement on that, but that was
my concern. Yes, I know a totally dead NiCd often won't
recharge, but what the hell.

Of course there is another solution.
A small button lithium cell would power the oscillator
for 10 years or more.

That takes all the fun out of it though.

... I want to charge a supercap
instead of a NiCd, which is why I mentioned stacked green LEDs.


The "BEAM" guys have things called Photo Poppers that do this.

Thanks for that pointer; I've been looking at what the
BEAMers have been doing but somehow missed Photo Poppers.

Mark L. Fergerson

 

[Mike Harding]

On Sat, 30 Aug 2003 12:25:08 +1000, "Jon" <gremlin@fastmail.fm> wrote:

You know half of you couldnt even take the criticism if you were to be an
editor.

Most of us who are regular contributors to the newsgroups
are frequently criticised by others, often in a _very_ hostile
and abusive manner - the fact that we continue to post
suggests we are well able to deal with criticism. In this case
it seems Leo is unwilling to debate with the people he
criticises - just throw rocks from afar.

Mike Harding

 

[Phil Allison]

"Mike Harding" <mike_harding1@hotmail.com> wrote in message
news:1c30lvo04ap3lnvpvad8irrdgs3tc6eied@4ax.com...

On Sat, 30 Aug 2003 12:25:08 +1000, "Jon" <gremlin@fastmail.fm> wrote:

You know half of you couldnt even take the criticism if you were to be an
editor.


Most of us who are regular contributors to the newsgroups
are frequently criticised by others, often in a _very_ hostile
and abusive manner - the fact that we continue to post
suggests we are well able to deal with criticism. In this case
it seems Leo is unwilling to debate with the people he
criticises - just throw rocks from afar.

** More like "pisses on from a great height" I would say.




............ Phil

 

[The real Andy]

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f4dacc7$0$14561$afc38c87@news.optusnet.com.au...

<snip>

** Be assured the Angels at SC and Jaycar are *watching* - in case
their interests are ever affected.

Funny you should say that, I have in the past found that I get more results
from complaining here about Jaycar/Electus than I do from phoning and
emailing. As soon as you post something about Jayar, you get a mysterious
email from a particular person wanting to know what the go is.

SO, if anyone has any beef with Jaycar, post here for an instant response.

 

[Phil Allison]

"K Dog" <kd@dontspamme.com> wrote in message
news:fLh4b.74529$bo1.6411@news-server.bigpond.net.au...

Hi,

Where does one purchase a 600w element? Preferrably a spiral element,
which
can have a fan next to it to blow the hot air through?

I checked out www.tobins.com.au but I'm unsure if the "240v spirals" are
the
ones I need or not.

** OK - this is getting fucking TEDIOUS !!!

Buy yourself a replacement stove-top coil element - 600 or 800
watts.

Blow a 120 mm PC fan through it.


Voila.


............ Phil

 

[John Crighton]

On Wed, 27 Aug 2003 16:49:13 +1000, "TT" <noname@noname.com> wrote:

I would like to vary the speed of a 12V 4W DC motor (brush type). I've
tested the motor and under load, it pulls less than 1A.

I was thinking of using an LM317T adjustable voltage regulator with trimpot
to do this. Is there any problems associated with using the regulator to
vary the speed? Do I need to add any extra protection to the output of the
regulator?

Thanks.



Hello TT,

here is another motor controller for you to look at.
http://www3.telus.net/chemelec/Projects/PWM.htm
Regards,
John Crighton
Hornsby

 

[The real Andy]

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f503dbb$0$4191$afc38c87@news.optusnet.com.au...

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote in message
news:3f503754$0$10355$afc38c87@news.optusnet.com.au...
"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f4dacc7$0$14561$afc38c87@news.optusnet.com.au...

snip

** Be assured the Angels at SC and Jaycar are *watching* - in
case
their interests are ever affected.

Funny you should say that, I have in the past found that I get more
results
from complaining here about Jaycar/Electus than I do from phoning and
emailing. As soon as you post something about Jayar, you get a
mysterious
email from a particular person wanting to know what the go is.



** So I am not the *only* one under covert serveillance !

Some guy called Jenkins or such like - right ?

Cant remember the exact name, but I have had a few of those emails.

 

[K Dog]

Sorry Phil if I was being a pain, but I don't know where you get the
600-800w stove-top coils from. I had a look at my local electrical supplier
but had no luck.

I was also thinking of getting a 500w halogen tungsten with the appropriate
fitting, and just using a fan in front of it.

Regards
Ben

Phil Allison <philallison@optusnet.com.au> wrote in message
news:3f51aed9$0$4188$afc38c87@news.optusnet.com.au...

"K Dog" <kd@dontspamme.com> wrote in message
news:fLh4b.74529$bo1.6411@news-server.bigpond.net.au...
Hi,

Where does one purchase a 600w element? Preferrably a spiral element,
which
can have a fan next to it to blow the hot air through?

I checked out www.tobins.com.au but I'm unsure if the "240v spirals" are
the
ones I need or not.



** OK - this is getting fucking TEDIOUS !!!

Buy yourself a replacement stove-top coil element - 600 or 800
watts.

Blow a 120 mm PC fan through it.


Voila.


........... Phil

 

[Phil Allison]

"K Dog" <kd@dontspamme.com> wrote in message
news:qbl4b.74908$bo1.2917@news-server.bigpond.net.au...

Sorry Phil if I was being a pain,

** I doubt that.





........... Phil

 

[David L. Jones]

On Sat, 30 Aug 2003 15:32:56 +1000, "The real Andy"
<ihatehifitrolls@yahoo.com.au> wrote:

Funny you should say that, I have in the past found that I get more results
from complaining here about Jaycar/Electus than I do from phoning and
emailing. As soon as you post something about Jayar, you get a mysterious
email from a particular person wanting to know what the go is.

SO, if anyone has any beef with Jaycar, post here for an instant response.

Well, I could complain about the crap 2002/2003 Electus catalog they
bought out, but I've already done that... :->
I didn't get an email though

Dave
---------------------------
(remove the "_" from my email address to reply)

 

[David L. Jones]

On Sun, 31 Aug 2003 12:50:35 +1000, John Tserkezis
<jt@techniciansyndrome.org.invalid> wrote:

The real Andy wrote:

Funny you should say that, I have in the past found that I get more results
from complaining here about Jaycar/Electus than I do from phoning and
emailing. As soon as you post something about Jayar, you get a mysterious
email from a particular person wanting to know what the go is.

SO, if anyone has any beef with Jaycar, post here for an instant response.

Their Bankstown store would fail an ISO9002 audit under static control. Or,
should I say, distinct lack thereof.

Only the Bankstown store? :->

Dave
---------------------------
(remove the "_" from my email address to reply)

 

[KLR]

On Sun, 31 Aug 2003 11:43:18 GMT, "K Dog" <kd@dontspamme.com> wrote:

Sorry Phil if I was being a pain, but I don't know where you get the
600-800w stove-top coils from. I had a look at my local electrical supplier
but had no luck.

Have you got a Haymans Electrical locally ?

Or someone who repairs whitegoods ?

Even if you went to an electrical retailer such as retra-vision,
Harvey norman etc - they may be able to tell you - or at least find a
model that uses elements of that wattage and their part number so you
could order ?

Finally - regular checks of rear of these stores you often find many
old stoves etc waiting to be dumped that have been traded in or
removed for the customer when they replaced them. Same with rubbish
dumps (often they sell items from the tip for next to nothing) and so
on.


I recently scrapped my old Chef stove and the elements still worked
fine so its a shame this article wasn't posted earlier as you could
have had them and the mounting hardware for the $10 or so it would
cost to parcel post them .
I hate waste.

I was also thinking of getting a 500w halogen tungsten with the appropriate
fitting, and just using a fan in front of it.

Regards
Ben

Phil Allison <philallison@optusnet.com.au> wrote in message
news:3f51aed9$0$4188$afc38c87@news.optusnet.com.au...

"K Dog" <kd@dontspamme.com> wrote in message
news:fLh4b.74529$bo1.6411@news-server.bigpond.net.au...
Hi,

Where does one purchase a 600w element? Preferrably a spiral element,
which
can have a fan next to it to blow the hot air through?

I checked out www.tobins.com.au but I'm unsure if the "240v spirals" are
the
ones I need or not.



** OK - this is getting fucking TEDIOUS !!!

Buy yourself a replacement stove-top coil element - 600 or 800
watts.

Blow a 120 mm PC fan through it.


Voila.


........... Phil

 

[Eric]

What's the volts on the 2N3055 base?
It should be 14.2 volts = 12V + (4*0.6 Volts), Emitter should be about 13.6
Volts.

"dsmith" <ds@nospam.com> wrote in message
news:3f51d578@news.comindico.com.au...
: I am looking at a circuit it is some kind of regulator in an organ dating
: back to 1971 - wow!
:
: The transistor is a 2N3055; 25v+ on the collector, the base is fed from
the
: 25v+ through a 390ohm 1 watt resistor, decoupled by a 2000mf electro to
: ground.
: The bias is set by four silicon diodes connected from the base to the
: 12volt+ line.
: The output from the emitter I would expect to be about 14volts +.
: The organ is not in my locale, so I can't check it. The owner says he is
: getting 17v+ from the emitter, doesn't sound right to me; any thoughts
:
:
:

 

[John Crighton]

On Sat, 30 Aug 2003 15:32:56 +1000, "The real Andy"
<ihatehifitrolls@yahoo.com.au> wrote:

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f4dacc7$0$14561$afc38c87@news.optusnet.com.au...

snip

** Be assured the Angels at SC and Jaycar are *watching* - in case
their interests are ever affected.

Funny you should say that, I have in the past found that I get more results
from complaining here about Jaycar/Electus than I do from phoning and
emailing. As soon as you post something about Jayar, you get a mysterious
email from a particular person wanting to know what the go is.

SO, if anyone has any beef with Jaycar, post here for an instant response.


Hello All and the Jaycar watching angels,

I don't have a beef but I would like to heap praise on a tall
young man called Greg who works at the St Leonards/Gore Hill
shop. I rang up about a BD681 transistor, explained they come
in a couple of different packages (TO126 thick TO225 thin).
He knew exactly what I was talking about, told me the thickness
of both packages over the phone as a double check, so that my
time would not be wasted, by coming in and being disappointed.
Excellent service.
Hello Jaycar Managment, think Greg, think pay rise.
Do not loose this clever, courteous, efficient young man.

While I am here, I might as well hurl a brick bat at a lousy
construction technique used by Codan on their HF4000
transceiver.
Visualise a double sided printed circuit board. Visualise
small power transistors in TO225 packages being used
as stand off spacers for the PCB. The same screw holds
down the PCB which then clamps the power transistor
to the heatsink. Now, the legs on the power transistor
are soldered underneath the board and are short as possible
meaning there is no "give" in the leads for mechanical
alignment as the screw is tightened down. The transistor
package cracks near the lead entry point or the tracks
on the PCB pull off slightly. Codan saved a few screws
and tiny spacers and reduced the reliability of the equipment.
If the transistor had its own mounting screw and longer
lead length then the transistor and PCB tracks would be OK.


Hello Mike Harding and the Group of course,
Mike, in your study of mounting power transistors where
the insulating bush warmed up and became a problem
did you have a look at the all plastic type case for example
as used in the BD681 with TO126 case ?
I was just wondering how good that hard plastic base
was (that requires no insulating mica washer) compared
to the conventional metal base and mica washer
in making good thermal contact.

Regards to All,
John Crighton
Hornsby

 

[Rod]

On Sat, 30 Aug 2003 15:52:09 +1000, "Joug Kim" <xyz@zyx> wrote:

Assume that we have a coil (with following specs) vertically placed on a
wooden table.

Coil : 100 windings, radius of 50mm, current passing through 50mA

I want to measure magnetic field strength at various points around the coil.
The max distance for the measurement is 1meter. How can I do this
measurement?

Have you had a look for "Hall Effect Transducers" like the ones in
"Brushless DC motors" used in fans/ Disc drives and the like?