Solid State Relays and EMI

[Clarence]

"Asa Cannell" <acannell@wwc.com> wrote in message
news:51ca721c.0409160852.69f397c5@posting.google.com...

acannell@wwc.com (Asa Cannell) wrote in message
news:<51ca721c.0409151242.4001e583@posting.google.com>...
Anyone sell off the shelf inductors in the range of 1 Henry? Everyone
I call can make it custom but doesn't have off the shelf items.

Asa
This is for a filter so current will be below 1ma. Tolerance +/- 20%,
size should be less than a few CC's. I found some:

www.rencousa.com

Has an incredible line up of up to 47H in a shielded package .3" x
.725" @ 25$ each with two week lead time in quantities of 10, qty 50 =
$9!
Asa

http://www.coilcraft.com/

Do an INDUCTOR search. I got 20 hits. lots to choose from, Tiny SM and small
through hole. You can get samples (up to five) of each free! So you should
find something suitable.

Also try "Top Magnetic" for those values. They DO have them as standard. Maybe
also samples.

There are about 250 Inductor company's at this time. Most are very keen on
providing samples for getting designed into a product.

 

[Lewin A.R.W. Edwards]

reading, somewhere in the 730 pF plus or minus 30 pF. These caps would
be old, maybe more than 30 years old judging by the date code. But I

Says it's 10%. So the minimum they should be is 738 pF. But most of

Buy a brand new one. Verify your meter is giving sane results.

 

[Watson A.Name - \"Watt Su]

"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:3hz2d.4084$n16.2168@newsread2.news.atl.earthlink.net...

reading, somewhere in the 730 pF plus or minus 30 pF. These caps
would
be old, maybe more than 30 years old judging by the date code. But
I

Says it's 10%. So the minimum they should be is 738 pF. But most
of

Buy a brand new one. Verify your meter is giving sane results.

Oh yeah, maybe I should'vc mentioned that. I have a bag of 470 pF 1%
silver mica caps, and when I measure those with the meter, they measure,
for example, 468.8 pF, 471.8 pF, 467.5 pF, and two in parallel measure
940.3 pF. So yes, I verify the accuracy of the meter on occasion. And
I'd say that it's fairly accurate.

 

[Spehro Pefhany]

On Thu, 16 Sep 2004 22:28:24 -0700, the renowned "Watson A.Name -
\"Watt Sun, the Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

Among the stuff that I scrounged a week or two ago I got bag of a
hundred capacitors. I think they're ceramic, and I'll describe the
case. It's black and 5 mm square by 2mm thick, and is labeled

CK05
BX
821K

on one side and

200V
A V X
7322

on the other side. I assumed that they were 820 pF, so I measured a
dozen of them with the AADE LC meter IIB. I got a consistently low
reading, somewhere in the 730 pF plus or minus 30 pF. These caps would
be old, maybe more than 30 years old judging by the date code. But I
would think that ceramics shouldn't change that much over the years.
Were they just not making caps right back then?

I checked for them using Google, and got this:
http://www.mouser.com/index.cfm?&handler=data.listcategory&D=80-CK05BX82
1K&terms=80-CK05BX821K&Ntt=*80CK05BX821K*&Dk=1&N=0&crc=true

Says it's 10%. So the minimum they should be is 738 pF. But most of
the dozen I checked were at or below this, so they are mostly out of
tolerance.

Eh?

Here's the actual data sheet:
http://www.avxcorp.com/docs/Catalogs/ck05-06.pdf

There was a big uproar about faulty 'mil-spec' resistors some years
ago..

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Tim Wescott]

yar wrote:

HI friends

I have afax motherboard I don't know the processor & the ROM the
IC"S as followin

***(M27C4001-6XFI 5880K 9935G SINGAPORE)(THE EPROM)

***(CONEXANT 10485-11 TH1332.9 9930)

***(RFX144V24-S R6675-55 RO0CKWELL97 98 B66530-3 MEXICO )

***(SEC KOREA 943 KM29W04QAT R7H052GD)

***(PFVIM66395M1 942102 JAPAN)



I DON'T KNOW THE FREQUENCIES OF THE CRYSTAL OSILLATORS I FIND THIS
NUMBER (53.76R9K)ON THE BODY OF ONE CRYSTAL THE SECOND ONEIS
CYLINDERICAL SHAPE& HAS THIS CODE(9XMU) THE LAST ONE IS VERY SMALL
CYLINDERICAL SHAPE WITHOUT ANY CODES OR NUMBERS

ANY HELP THANK YOU FOR ALL
I AM SORRY FOR MY HARD LANGUAGE LEVEL

Please don't shout. If your caps lock key is broken please get a new
keyboard.

The small cylindrical crystal is probably 32768Hz, and possibly the
larger one as well.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Peter Bennett]

On 17 Sep 2004 16:42:13 -0700, smpaladin@yahoo.com (smpaladin) wrote:

I am new to electronics and I need to know if there is a type of
switch that will assist me in reversing the polarity of an
electromagnet, as in the picture here
http://www.geocities.com/smpaladin/switch2.gif

I've asked this question before in a different group, but I keep
getting unclear answers about a relay or a DPDT switch.

What I want is a switch, like the green switch in the picture, that
will alternate the input/output currents between two wires, as long as
an outside current is applied to the switch. This way, I will be able
to reverse the polarity of an electromagnet as long as the outside
current is applied to the green switch. Is there any specific type of
switch that will accomplish this?

You can either use a DPDT switch, or use a DPDT relay, with an SPST
switch to control the relay.

If the wiring from the battery to the electromagnet is located where
you can easily reach it, I would use a simple DPDT switch.

If you want to be able to switch polarity while you are some distance
from the battery and electromagnet, then the relay and SPST switch
might be more appropriate.

What you have shown in that drawing is a relay and SPST switch.




--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

smpaladin@yahoo.com (smpaladin) wrote:

http://www.geocities.com/smpaladin/switch2.gif

I've asked this question before in a different group, but I keep
getting unclear answers about a relay or a DPDT switch.

You do indeed need a DPDT relay, the normally closed contacts wired
straight through and the normally closed contacts wired in reverse.

Is this for a class? If not, (how) are you planning on implementing
this circuit?

 

[Franc Zabkar]

On 17 Sep 2004 09:18:06 -0700, st_yar@yahoo.com (yar) put finger to
keyboard and composed:

HI friends

I have afax motherboard I don't know the processor & the ROM the
IC"S as followin

I don't believe any of the following devices are CPUs. Look for an
FC100 or FC200 device, maybe on the underside of the PCB (?)

***(M27C4001-6XFI 5880K 9935G SINGAPORE)(THE EPROM)

ST Microelectronics 4Mbit EPROM

This would contain the operational firmware.

***(CONEXANT 10485-11 TH1332.9 9930)

Smart DAA? Phone line interface?

***(RFX144V24-S R6675-55 RO0CKWELL97 98 B66530-3 MEXICO )

Conexant Monofax faxmodem with speakerphone and digital answering
machine capability.

http://www.conexant.com/servlets/DownloadServlet/100082A.pdf?FileId=315
http://www.conexant.com/servlets/DownloadServlet/100318b_pb.pdf?FileId=110

***(SEC KOREA 943 KM29W04QAT R7H052GD)

Samsung KM29W040AT 4Mbit flash memory:
http://www.samsung.com/Products/Semiconductor/Flash/NAND/4Mbit/K9F4008W0A/K9F4008W0A.PDF

I suspect this part provides 24 minutes of voice storage, as stated in
Conexant's Monofax datasheet.

***(PFVIM66395M1 942102 JAPAN)

Panasonic CMOS gate array???

I DON'T KNOW THE FREQUENCIES OF THE CRYSTAL OSILLATORS I FIND THIS
NUMBER (53.76R9K)ON THE BODY OF ONE CRYSTAL THE SECOND ONEIS
CYLINDERICAL SHAPE& HAS THIS CODE(9XMU) THE LAST ONE IS VERY SMALL
CYLINDERICAL SHAPE WITHOUT ANY CODES OR NUMBERS

ANY HELP THANK YOU FOR ALL
I AM SORRY FOR MY HARD LANGUAGE LEVEL

The FC100/200(M) controller/CPU requires a 32.768kHz RTC crystal. That
would be the very small (2mm dia?) cylinder.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Watson A.Name - \"Watt Su]

"smpaladin" <smpaladin@yahoo.com> wrote in message
news:6753235c.0409171542.49622063@posting.google.com...

I am new to electronics and I need to know if there is a type of
switch that will assist me in reversing the polarity of an
electromagnet, as in the picture here
http://www.geocities.com/smpaladin/switch2.gif

It's called a polarity reversal switch. See the diagram at the bottom
under double pole double throw switch. http://www.1728.com/project2.htm

You can wire a double pole, double throw relay similarly.

I've asked this question before in a different group, but I keep
getting unclear answers about a relay or a DPDT switch.

What I want is a switch, like the green switch in the picture, that
will alternate the input/output currents between two wires, as long as
an outside current is applied to the switch. This way, I will be able
to reverse the polarity of an electromagnet as long as the outside
current is applied to the green switch. Is there any specific type of
switch that will accomplish this?

 

[Watson A.Name - \"Watt Su]

"Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
news:bec993c8.0409171104.4aaf3ed@posting.google.com...

"Watson A.Name - \"Watt Sun, the Dark Remover\""
NOSPAM@dslextreme.com> wrote in message

news:<10kkte9p92stpfb@corp.supernews.com>...

Says it's 10%. So the minimum they should be is 738 pF. But most
of
the dozen I checked were at or below this, so they are mostly out of
tolerance.

Eh?

A lot of the stuff floating around on the surplus market are
factory rejects. Usual corporate policy is to sell such parts
unlabeled or scrub the labels, especially on mil-spec parts,
but this doesn't always happen.

Where exactly did you scrounge them from?

The Powers That Be decided that the college didn't need an electronics
program anymore, so they closed it down this summer. They gave the
rooms to another dept, and they just set all the contents of the drawers
(and even some of the drawers) out in the middle of the sidewalk for the
custodians to toss in the trash bin. I came along and scrounged what I
could manage to carry. I got a couple pounds of resistors, still im
bags, too. I'll have to check some of those to see if they're ok. I
got three hundred SGS-ATES 2N3055E power transistors still in the
styrofoam packaging paterial, probably worth a hundred or so. A couple
hundred sockets for the 2N3055s. A Cornell Dubilier capacitor
substitution box from a long, long time ago. A couple two-way radio PTT
microphones. A couple hundre 1000 uF 50V capacitors, Sprague, I
believe, but they're old timers and are at least five times the volume
of the more modern ones found in SMPSes. Anyway, I haven't had time to
look thru all the stuff to find out what I got. Maybe I'll sell some of
the stuff on Ebay.



> Tim.

 

[Watson A.Name - \"Watt Su]

<William P.N. Smith> wrote in message
news:hv2nk0hs4oe9ja6d43nq7fsvu3d55rke6b@4ax.com...

smpaladin@yahoo.com (smpaladin) wrote:
http://www.geocities.com/smpaladin/switch2.gif

I've asked this question before in a different group, but I keep
getting unclear answers about a relay or a DPDT switch.

You do indeed need a DPDT relay, the normally closed contacts wired
straight through and the normally closed contacts wired in reverse.

You forgot 'normally open'.

Is this for a class? If not, (how) are you planning on implementing
this circuit?

 

[Brian]

Without the resistor, when both diodes go to a logical "1", there would be
nothing to pull the output to a logical "1" (or +5 volts in this case).

"Christopher Collins" <christopher.m.collins@gmail.com> wrote in message
news:f4f3a83b.0409201410.370e25c@posting.google.com...

An AND gate can be made of two diodes and a resistor:

+5V
|
R
|
A -|<|--+---- OUT
|
B -|<|--+

Here, R is a resistor and the |<| thingies are small diodes.

As long as either of the inputs A and B is connected to ground
(logical 0),
the output will be a 0 as well (not exactly zero volts, since there's
a
voltage drop over the diode). If both inputs are open, or connected to
logical 1, the output will be a 1 as well. Hence, the output is the
logical
and of the inputs.

My question: What's the point of the resistor here? It seems to me
this could work without it.

Christopher

 

[Hal Murray]

An AND gate can be made of two diodes and a resistor:

+5V
|
R
|
A -|<|--+---- OUT
|
B -|<|--+

Here, R is a resistor and the |<| thingies are small diodes.

[snip]

My question: What's the point of the resistor here? It seems to me
this could work without it.

Without the resistor, how much current would you get through
one of the diodes when the inputis at 0V?

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

 

[Rich Grise]

On Monday 20 September 2004 06:24 pm, Hal Murray did deign to grace us with
the following:

An AND gate can be made of two diodes and a resistor:

+5V
|
R
|
A -|<|--+---- OUT
|
B -|<|--+

Here, R is a resistor and the |<| thingies are small diodes.

[snip]

My question: What's the point of the resistor here? It seems to me
this could work without it.

Without the resistor, how much current would you get through
one of the diodes when the inputis at 0V?

That's simple. All of it. ;-)

 

[Watson A.Name - \"Watt Su]

"Glenn Gundlach" <stratus46@yahoo.com> wrote in message
news:acb22b57.0409202047.405aba8f@posting.google.com...

"Brian" <bellis350@comcast.net> wrote in message
news:<Xc2dnd6w57-JytLcRVn-jA@comcast.com>...
Without the resistor, when both diodes go to a logical "1", there
would be
nothing to pull the output to a logical "1" (or +5 volts in this
case).

"Christopher Collins" <christopher.m.collins@gmail.com> wrote in
message
news:f4f3a83b.0409201410.370e25c@posting.google.com...
An AND gate can be made of two diodes and a resistor:

+5V
|
R
|
A -|<|--+---- OUT
|
B -|<|--+

Here, R is a resistor and the |<| thingies are small diodes.

As long as either of the inputs A and B is connected to ground
(logical 0),
the output will be a 0 as well (not exactly zero volts, since
there's
a
voltage drop over the diode). If both inputs are open, or
connected to
logical 1, the output will be a 1 as well. Hence, the output is
the
logical
and of the inputs.

My question: What's the point of the resistor here? It seems
to me
this could work without it.

Christopher

We used to call this MML or Mickey Mouse Logic. Handy for CMOS (no
loading) and slow signals like door open switches.
gg

Didja hear that Michael Eisner is going to be leaving Disney?

Because it's a Mickey Mouse Operation. ;-)

 

[Rich Grise]

On Monday 20 September 2004 10:37 pm, Watson A.Name - "Watt Sun, the Dark
Remover" did deign to grace us with the following:

"Glenn Gundlach" <stratus46@yahoo.com> wrote in message

We used to call this MML or Mickey Mouse Logic. Handy for CMOS (no
loading) and slow signals like door open switches.
gg

Didja hear that Michael Eisner is going to be leaving Disney?

Because it's a Mickey Mouse Operation. ;-)

I heard that Mickey wants to divorce Minnie on the grounds of
insanity because she's fucking Goofy.

Cheers!
Rich

 

[Walter Harley]

"Michael" <maxel@berkeley.edu> wrote in message
news:ce5951b4.0409221342.44bb1c8b@posting.google.com...

I am performing a test to measure the impedance through electrode pads
placed on opposite parts of the human body. The protocol requires that
the measurement be made by maintaining an AC sine current of 200mArms,
sweeping the frequencies from 200kHz to 5MHz, and measuring the Vrms
between one electrode and a reference point on the body. The impedance
is to be calculated by dividing this voltage by the known 200mArms
current.

How do I sweep frequencies while maintaining a constant 200mArms
current using a HP 33120A (waveform generator w/ 0-15MHz freq and
0-10V peak to peak) or a HP 4192A (impedance analyzer w/ 0-15MHz freq
and -1V-+1V peak to peak)? Can I construct a circuit external to one
of these units and accomplish the 200mArms sweep? If not, what
lowest-cost set-up could?

There are some questions which should not be answered, because answering
them just increases the risk of harm. This is one of them.

It is true that high frequencies reduce the risk of electrocution, because
of the "skin effect" (which has nothing to do with your skin, it applies to
wires also). (This effect also means that if you measure with those
frequencies, you're not measuring anything much to do with the human body
per se.)

But it is also true that any time you get near a human body with an
electrode and a power source, there is a risk of electrocution. 200mA at
lower frequencies will definitely kill, and if a fault occurs in your
equipment the subject could be exposed to arbitrary frequencies and
currents. You better believe HP didn't design that gear with the intent of
connecting it to a person.

You need two things, if you're going to do this in an educational/research
environment:

1. Contact with, and permission from, your human studies review board.

2. A medically approved stimulus apparatus (which will contain certain
safety mechanisms that guarantee that the stimulus is non-lethal).

 

maxel@berkeley.edu (Michael) wrote:

I am performing a test to measure the impedance through electrode pads
placed on opposite parts of the human body. The protocol requires that
the measurement be made by maintaining an AC sine current of 200mArms,

You better check that spec again, two hundred milliamps? Diathermy
seems to happen at 500 mA... Maybe you mean microamps. Please don't
kill anybody getting this wrong!

http://www.rjlsystems.com/research/bia-principles.html

 

[Spehro Pefhany]

On 24 Sep 2004 10:56:48 -0700, the renowned shoppa@trailing-edge.com
(Tim Shoppa) wrote:

Was the CA3005 a two-NPN matched pair, a NPN/PNP
pair, two transistors in a cascode config, or something else?

Tim.

An RF differential pair with a current sink on the emitter, all in a
12-lead TO-5.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[R.Lewis]

"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409230106.31f6fb79@posting.google.com...

"Mark VB" <mark.vanborm@telenet.be> wrote in message
news:<IGf4d.254102$4N6.13070449@phobos.telenet-ops.be>...
"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409220336.56fe15f@posting.google.com...
I'm looking for a COB(chip on board) PCB with a blinking led. This can
be found in toys and electronic candles.
I need to find manufacturers or resellers which I think are mainly in
China.
If the cob+led isn't available, I'll also be interested just in the
cob.
I've already seen some kits from kitsrus and some cob from Comedia but
they don't do what I need: 10Hz, 1/4 duty-cycle.

I'd appreciate any help you could give me, even if there are other
newsgroups that I could ask for.


Thanks in advance!

Hi,

The simplest way to make a led blinking is to use a simple NAND- or
NOR-gate, where the output is coupled back to the input via an
RC-network.

I use a 74HC132 (Quad 2-input NAND Schmitt Trigger) to "scan" 7-seg
displays. When you use a 74HCT132 instead, you will get a duty-cycle
around
28%. I do mention that variations in power-supply and temperature will
result in other output-characteristics.

If higher precision is needed, you can use an NE555 or LM555 (Timer IC)
with
an adjustable duty-cycle and temperature stability better than 0.005%
per
°C.


Mark Van Borm

Thanks for your reply.
I've already tried that option, but since I'm needing lots of them,
that would be expensive to make the PCB, buy the components and
assembly them.
What I'm really looking for is a COB like comedia have. I've tried it
but they don't have continuous operation and with 10Hz.
The COB is ready to run and if it has the led, it'd be better.

Roy Conrad

I have missed the first part of the thread but if all yo want is to 'blink'
a led why do you need to be so complicated?
A surface mount discrete flasher uses very few components and is thus small
and cheap - see how the people that manufacture such things do it.