magnetic field

[Mike Deblis]

<kolotun@gmail.com> wrote in message
news:1112970906.876899.71750@g14g2000cwa.googlegroups.com...

I would appreciate your opinions about the following device:

"Smart Tweezers LCR RCL RLC Meter Digital MultiMeter SMD"

I found on eBay. Looks like an interesting concept but is it as good as
the seller tells?

have you seen the Peak Electronics LCR tester:

http://www.peakelec.co.uk/content/products/atlaslcr.html

They have other nice small test equipment and good prices too...

Mike

 

[Guy Macon]

Glenn Ashmore wrote:

With a little immagination
you could even mount a tweezer on the front end.

Or you can simply buy a set of BK Precision TL 8 Tweezer Test Leads
for $25. [ http://www.bkprecision.com/showproduct.asp?pn=TL%208 ]
[ http://www.testequipmentdepot.com/b+k%20precision/bktestleads.htm#TL-8 ]

"Glenn" wrote

Having it all in a tweezer is actually fairly useful. The alternative
is to try to get a part to hold still while you get two probes from a
meter on it.

Or you can simply buy a set of BK Precision TL 8 Tweezer Test Leads
for $25. [ http://www.bkprecision.com/showproduct.asp?pn=TL%208 ]
[ http://www.testequipmentdepot.com/b+k%20precision/bktestleads.htm#TL-8 ]

 

[Glenn]

You could and that might be OK for some applications but I find it very
nice to not have to turn my head and shift my focus to go between
identifying the physical location of the part (with the tweezers) and
the value (with the tweezer display). I've used various tweezer leads
and contacts before, and have had a DMM on the bench prior to tweezers,
but I generally end up with yet another pair of leads dangling down or
across the workspace and knocking stuff around (and onto the floor).
Maybe I'm just a klutz with bad eyesight but I do like the smart
tweezers better.

Glenn

Guy Macon wrote:

Or you can simply buy a set of BK Precision TL 8 Tweezer Test Leads
for $25. [ http://www.bkprecision.com/showproduct.asp?pn=TL%208 ]
[ http://www.testequipmentdepot.com/b+k%20precision/bktestleads.htm#TL-8 ]

 

[Michael A. Terrell]

Robert Baer wrote:

Must have been specialty parts at a specialty price.
Ordinary capacitors run from 5% to 20%, and the few 2% caps are wound
plastics.
I dare say that the only SMD caps are ceramics, meaning that the
accuracy is limited by the construction and physics of construction.
Green ceramic caps change size and shape when fired; cannot get
around that.
Now, one *could* test to a tight spec; bin the passes for hi $ and
the failures for regular sales.
BTW, do you know the temp curves for X5R, Y5V, etc???

Yes, I do know the differnt curves. Not everyone builds $2 radios or
cheap consumer trinkets. The ones that don't need real parts instead of
the floor sweepings.

Its been almost four years, but I believe they were under a nickle
each because I got them by the hundred from the stock room and I only
did that on 5 cent and under parts. We used a lot of precision parts
including .1% resistors. The radios were $8,000 each and custom built.

We used a lot of microwave ceramic SMD chips that had to be high
precision to reduce test and alignment time.

Take a look at: http://www.avxcorp.com/docs/catalogs/ccog.pdf for
off the shelf precision ceramic SMD caps.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

 

[Jim Gregory]

Originally, Edison promoted DC for only very short town distances, but then
Tesla proved that AC could be distributed far and wide, stepped up and down,
and merged/synchronised easily between generating stations onto a grid or
networked system.
Even autos now have alternators to generate AC which is then rectified to
charge/maintain the battery.
They once used to have dynamos for making DC, like bicycles may still do.
DC is converted only in AC mains appliances that need its presence.

"hartly" <hartlyuk@yahoo.com> wrote in message
news:1f73b571.0504110818.b5cac53@posting.google.com...

I heard on tv that public electricity supply was originally D.C.
Why did they send D.C. down the wires instead of A.C.?
I thought that elctricity is generated as A.C. in spinning
generators, and has to be converted to D.C.
Thanks, Hartly.

 

[Charles Schuler]

"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504111419.3c1dbc1f@posting.google.com...

Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

How many Watt transformer do I need to use this charger in the UK
where we have 240V? The output of the charger itseff is only 65W, but
the input is more, but I'm not sure how to take the phase into
account.

Power = volts x amps so its about 65 watts. Given allowance for less than
100% efficiency, 100 to 150 watts would be my guess.

 

[Ken Taylor]

"Charles Schuler" <charleschuler@comcast.net> wrote in message
news:RfydnbnW5IL7ncbfRVn-2Q@comcast.com...

"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504111419.3c1dbc1f@posting.google.com...
Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

How many Watt transformer do I need to use this charger in the UK
where we have 240V? The output of the charger itseff is only 65W, but
the input is more, but I'm not sure how to take the phase into
account.

Power = volts x amps so its about 65 watts. Given allowance for less than
100% efficiency, 100 to 150 watts would be my guess.

If the input spec's are correct then the input could be up to 144W so,

assuming inefficiencies as you suggest, I'd be looking to maybe 175-200W.
Seems ridiculous for the job but there you go.

Ken

 

[John Fields]

On 11 Apr 2005 15:19:24 -0700, electronicfur@yahoo.co.uk (EF) wrote:

Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

How many Watt transformer do I need to use this charger in the UK
where we have 240V? The output of the charger itseff is only 65W, but
the input is more, but I'm not sure how to take the phase into
account.

---
The input is 120VAC @ 1.2A, so that's 120V * 1.2A = 144VA, not 144W,
which pretty much takes the phase into account.

Assuming the transformer you get is 80% efficient anf you can get
144VA out of its secondary, you'll need at least a 180VA transformer.

Probably the closest thing to that is 200 to 250VA, something like a
Signal transformer DU-1/4. About 12 lb, about $120.

http://www.belfuse.com/signaltransformer/ProdList-PowerIsolation.asp?pType=ALL&pReset=y&pOrder=BelPartNumber

--
John Fields
Professional Circuit Designer

 

[Joel Kolstad]

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:WMp6e.4031$lP1.1483@newsread1.news.pas.earthlink.net...

That Mondo Technology Super Probe is a far better instrument for the
money, and ther is no hype (no 5 digit display for a 3 digit device).

Strictly speaking ("a better investment"), you're probably right. But I
think they're aimed at two different markets; take a look at the features
for yourself.

The Smart Tweezers has a MUCH better display, IMO.

 

[Robert Baer]

Mike Deblis wrote:

kolotun@gmail.com> wrote in message
news:1112970906.876899.71750@g14g2000cwa.googlegroups.com...

I would appreciate your opinions about the following device:

"Smart Tweezers LCR RCL RLC Meter Digital MultiMeter SMD"

I found on eBay. Looks like an interesting concept but is it as good as
the seller tells?


have you seen the Peak Electronics LCR tester:

http://www.peakelec.co.uk/content/products/atlaslcr.html

They have other nice small test equipment and good prices too...

Mike


*MUCH* more believable; the cal traceability is a definite *plus*.

 

[Robert Baer]

Michael A. Terrell wrote:

Robert Baer wrote:

Must have been specialty parts at a specialty price.
Ordinary capacitors run from 5% to 20%, and the few 2% caps are wound
plastics.
I dare say that the only SMD caps are ceramics, meaning that the
accuracy is limited by the construction and physics of construction.
Green ceramic caps change size and shape when fired; cannot get
around that.
Now, one *could* test to a tight spec; bin the passes for hi $ and
the failures for regular sales.
BTW, do you know the temp curves for X5R, Y5V, etc???


Yes, I do know the differnt curves. Not everyone builds $2 radios or
cheap consumer trinkets. The ones that don't need real parts instead of
the floor sweepings.

Its been almost four years, but I believe they were under a nickle
each because I got them by the hundred from the stock room and I only
did that on 5 cent and under parts. We used a lot of precision parts
including .1% resistors. The radios were $8,000 each and custom built.

We used a lot of microwave ceramic SMD chips that had to be high
precision to reduce test and alignment time.

Take a look at: http://www.avxcorp.com/docs/catalogs/ccog.pdf for
off the shelf precision ceramic SMD caps.

I see that one could *buy* small values of NPO caps speeced at 1%,

but according to the same data sheet, they can be as bad as 2.5% - which
appears to support my general statement.

 

[Jim Gregory]

Check inside charger to see if there is a mains i/p voltage selector setting
(series/parallel switch for primaries), as there may be the opportunity of
setting it to 230V.
Otherwise
If you are bringing the charger to the UK, you may source the step-down
transformer
in the UK. You could buy a 200VA, 240V to120V model from, for example,
Maplin

http://www.maplin.co.uk/Module.aspx?ModuleNo=13358&TabID=1&source=15&WorldID=&doy=12m4

"John Fields" <jfields@austininstruments.com> wrote in message
news:bgam51l69n2ra64l4nm6r8fl8ilfgitikm@4ax.com...

On 11 Apr 2005 15:19:24 -0700, electronicfur@yahoo.co.uk (EF) wrote:

Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

How many Watt transformer do I need to use this charger in the UK
where we have 240V? The output of the charger itseff is only 65W, but
the input is more, but I'm not sure how to take the phase into
account.

---
The input is 120VAC @ 1.2A, so that's 120V * 1.2A = 144VA, not 144W,
which pretty much takes the phase into account.

Assuming the transformer you get is 80% efficient anf you can get
144VA out of its secondary, you'll need at least a 180VA transformer.

Probably the closest thing to that is 200 to 250VA, something like a
Signal transformer DU-1/4. About 12 lb, about $120.

http://www.belfuse.com/signaltransformer/ProdList-PowerIsolation.asp?pType=ALL&pReset=y&pOrder=BelPartNumber

--
John Fields
Professional Circuit Designer

 

[Chuck Harris]

Robert Baer wrote:

Take a look at: http://www.avxcorp.com/docs/catalogs/ccog.pdf for
off the shelf precision ceramic SMD caps.

I see that one could *buy* small values of NPO caps speeced at 1%, but
according to the same data sheet, they can be as bad as 2.5% - which
appears to support my general statement.

The +/- 2.5% you are citing, is a spec that describes the result of soldering
abuse. 5 seconds at 500F, is much longer, and hotter, than is typically necessary.

If you need better performance than the +/-2.5% figure, than you should be
quicker with your soldering, or use a conductive epoxy.

The capacitors are as spec'd, when they are delivered, what you do with them
after that may change them.... just like most things in life.

-Chuck

 

[Guy Macon]

kolotun@gmail.com wrote:

Thank you for your replies. I'm going to purchase the device and let
you know how it fared.

Sounds like a decent tool. It has limitations, but what tool doesn't?

I would very much like to see a list of the ICs that are in it, so
if you decide to open the case, please write down the part numbers
and post them.

 

[CWatters]

"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504111419.3c1dbc1f@posting.google.com...

Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

Can we ask what it's for?

 

[Tomi Holger Engdahl]

"js5895" <JoshTmp@nycap.rr.com> writes:

Hi,

Do you think it's possible to get a PS/2 computer keyboard to
work with a Playstation 2. Because I have an extra keyboard
collecting dust, and I would like to try to make it work.
I think the keyboard's chip has to be compatible though.
I only got it to light up, is this connection right:
ground-------------------+5
clock--------------------clock
PS/2 Keyboard data---------------------data Playstation 2 USB
+5-----------------------ground

If that what you say as "Playstation 2 USB" is really
an USB interface, the you definately got the pinout wrong.

The pinout of standard USB port is the following:
1 +5
2 -Data
3 +Data
4 GND

There are no separate pins for clock and data!



--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

 

[Watson A.Name - \"Watt Su]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:4254C718.52BD4BC7@earthlink.net...

"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:

alondra101@hotmail.com> wrote in message
news:1112824555.472068.130380@l41g2000cwc.googlegroups.com...

It looks as if they have essentially lifted the pages out of the
ol'
GE
Miniature Lamp Catalog and put them into this .PDF, which is
nearly 3
megs. But this is _the_ definitive lamp catalog, with all those
old
specialty lamps like #47 lamps used in the old radois, etc. Every
bookshelf should have this on it, or at least saved on their hard
disk.
It's a classic.

http://www.sunraylighting.com/pdf/Catalog.pdf

Is anyone getting my Google postings? The last one I did hardly
anyone
postd a followup. I'm thinking that Google has an excellent inbound
news system, but for outbound messages it sucks.

The one about the lamps showed up on Earthlink, but I think Google
groups are starting to be black holed for excessive spam.

Maybe so; I noticed that there were a lot of adverts in their posts.

Last year at work, when CSU shut down their news servers, I asked our
netheads what the IP was for the replacements. They said, sorry, it's
gone; just use Google. So I was SOL at work. Sometimes I've run across
something that I want to post, and I'll use Google. Sometimes I'll just
email it to myself and later at home I'll cut and paste the URL or
whatever into a post. I guess that's what I'll have to do and forget
about using Google to post.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

 

[Jim Gregory]

EF
*If* it proves switchable, ie, two primaries arrangeable either in parallel:
115V or in series: 230V, and you adjust it for the higher input, when you
come over here you'll need to fit a new 3-pin plug, 13A (max) type but with
a 2 or 3 Amps 1" fuse inserted... this connector carries an optional ground
connection, as well.
Any electrical shop, DIY store, pound shop, ironmongery sells them.

"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504130232.44438c6d@posting.google.com...

"CWatters" <colin.watters@pandoraBOX.be> wrote in message
news:<UxS6e.63126$Xm2.4493350@phobos.telenet-ops.be>...
"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504111419.3c1dbc1f@posting.google.com...
Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

Can we ask what it's for?

It's to charge a 36V 8Ah battery pack for an electric motor. I'm using
the motor on a bicycle, so have to carry charger with me on the bike,
which is why I wanted to see if a 100VA transformer would be
sufficient, as they are a lot lighter. But from everyone's advice it
looks like it would have to be 200VA.

But I'll follow Jim's suggestion first and open it up to see if it is
switchable.

Thanks,
EF

 

[Vidar Lřkken]

alondra101@hotmail.com wrote:

Add a followup to this (google groups) message if you can read it.
Thanks.

Just trying to see if these google groups messages are really
blackholed by other newsgroup providers.

Go away!
FUT: alt.test

--
MVH,
Vidar

www.bitsex.net

 

[John Fields]

On 13 Apr 2005 03:32:12 -0700, electronicfur@yahoo.co.uk (EF) wrote:

"CWatters" <colin.watters@pandoraBOX.be> wrote in message news:<UxS6e.63126$Xm2.4493350@phobos.telenet-ops.be>...
"EF" <electronicfur@yahoo.co.uk> wrote in message
news:37e4eaf1.0504111419.3c1dbc1f@posting.google.com...
Hi I'd appreciate some help.

I have a NiMh battery charger which has AC input of 100~120VAC
50~60HZ, 1.2A.

It outputs at 36VDC, 1.8A.

Can we ask what it's for?

It's to charge a 36V 8Ah battery pack for an electric motor. I'm using
the motor on a bicycle, so have to carry charger with me on the bike,
which is why I wanted to see if a 100VA transformer would be
sufficient, as they are a lot lighter. But from everyone's advice it
looks like it would have to be 200VA.

But I'll follow Jim's suggestion first and open it up to see if it is
switchable.

---
If it's not switchable, you may want to look into getting an
autotransformer. About 1/3 the weight for the same VA rating and
cheaper, to boot.

Something like Part Number 120 at:

http://www.belfuse.com/Data/DBObject/page_30.pdf

--
John Fields
Professional Circuit Designer