Chip with simple program for Toy

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

Last week the teller bitch at the credit union tried to shortchange
me. I asked for and signed for $600, and after she handed it to me
I counted it and I got $500, so I counted it again - same, and I
handed it back and said you had better count it. Yep, a hundred
short. I wished her a Merry Christmas as I left. ;-) Be sure
you count your money before you step away from the teller!
Click to expand...
Make sure you do it without removing it from his/her sight, i.e.
right on the counter. Normally well trained tellers count it
twice, once for themselves, and once while transferring it to you.
The fact that you got your money indicates to me that either you
didn't remove it from sight, or that your nomenclature is
undeserved. The latter is probably true anyway.

--
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!
 
"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:kM9cl4CmM+xBFwTF@jmwa.demon.co.uk...
I read in sci.electronics.design that Watson A.Name - "Watt Sun, the
Dark Remover" <NOSPAM@dslextreme.com> wrote (in
10sfjkjevq2lp59@corp.su
pernews.com>) about 'Circuit that produces a tingling sensation in the
fingers.', on Mon, 20 Dec 2004:

Last week the teller bitch at the credit union tried to shortchange
me.
I asked for and signed for $600, and after she handed it to me I
counted
it and I got $500, so I counted it again - same, and I handed it back
and said you had better count it. Yep, a hundred short. I wished
her a
Merry Christmas as I left. ;-) Be sure you count your money before
you
step away from the teller!

It's only a 0.8 dB error, for goodness sake! (;-)
Click to expand...
Heh. Yeah, but hey, it's _my_ 0.8 dB!!

And this isn't the only time I've been shorted by them recently. I got
several rolls of dollar coins, and a couple rolls came 2 short, and
another came with four quarters. Then another roll came with a Mexican
100 Peso coin in it. I checked and one of those was auctioned for 40
cents on ebay, but no one bought it. So I think I got a worthless coin
there, too. I complained and they credited by acct with the shortage.
Turkeys.

--
Regards, John Woodgate, OOO - Own Opinions Only.
Click to expand...
 
"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:khf6t0h7a8oa2d1429gnt2spcu4f29lqcr@4ax.com...
On Wed, 29 Dec 2004 15:20:58 -0500, "Bill Stock" <Me7@Privacy.net
wrote:

I've got a temperature sensor circuit which is subject to severe
condensation. What's a good protective coating? I was thinking of filling
the enclosure with silicone caulk, but I imagine some spray coating might
be
better?



Most air-dry silicone caulk has acetic acid, which is bad news for
electronics.

Epoxy is good, or an acrylic casting compound. Use slow-set epoxy...
the fast stuff gets hot as it cures. The resin they use to fiberglass
boats is good and cheap. Mold-making (2-part) silicone is excellent.

For conformal coating, ordinary polyurethane varnish is pretty good.

John
Click to expand...
Thanks John,

Epoxy seems to be the favourite. Although I imagine repairs would be a
bitch.

How do you find the drying time for a polyurethane dip? I think it would
take a while to harden? Do you favour any particular brand?
 
I would not rely on conformal coating on the circuit board. It is a
good vibration damper and protects against, at best, light levels of
dew formation. If you expect to have water condensation than I would
recommend epoxy. But it will depend on if your sensor operates mostly
in a narrow range of temperatures or across a broader range such as
below freezing to 90 deg. F.
 
"JeB" <no@spam.org> wrote in message
news:91l6t0tu9a617ggs51sdeesqerh85m9n27@4ax.com...
On Wed, 29 Dec 2004 15:20:58 -0500, "Bill Stock" <Me7@Privacy.net
wrote:

I've got a temperature sensor circuit which is subject to severe
condensation. What's a good protective coating? I was thinking of filling
the enclosure with silicone caulk, but I imagine some spray coating might
be
better?


I'd imagine whatever you seal things up with is going to effect the
temperature response of the unit. Will that be a problem?
Click to expand...
JeB,

The sensor is not on the board, it's attached to a short (30") cable. The
sensor actually measures water temperature, hence the serious condensation.
I used connector coating to waterproof the sensor, which seems to slow down
the temp response a bit, but not too bad.
 
"Nicholas O. Lindan" <see@sig.com> wrote in message
news:q1ZAd.3371$JC2.2047@newsread2.news.atl.earthlink.net...
"Bill Stock" <Me7@Privacy.net> wrote

I've got a temperature sensor circuit which is subject to severe
condensation. What's a good protective coating? I was thinking of filling
the enclosure with silicone caulk, but I imagine some spray coating might
be
better?

Is it possible to have just the sensor in the condensing atmosphere?
Click to expand...
Yes, but the non condensing atmosphere is outside, so then I've got
snow/ice/critters to worry about. The sensor measures the temperature of an
ornamental pond (coverered) and controls a heater to prevent fishsicles.


If not, then you will need a small 'Hoffman Enclosure' with a NEMA (I
forget the #) rating.

If you use epoxy you may want to use marine epoxy, that's the stuff
they make boat hulls out of, available at boat shops. Also called
'West Epoxy'.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
Click to expand...
 
Maybe Bee's Wax?? Seriously, melted Bee's Wax applied over the item, it
will not affect the ability to sense temperature changes as long as the
ambient does not exceed the melting temp of the wax. I presume the sensor is
immersed in the pond, water covered?? IMHO
"Bill Stock" <Me7@Privacy.net> wrote in message
news:JvudnZG0O7A4-UncRVn-sw@rogers.com...
"Nicholas O. Lindan" <see@sig.com> wrote in message
news:q1ZAd.3371$JC2.2047@newsread2.news.atl.earthlink.net...
"Bill Stock" <Me7@Privacy.net> wrote

I've got a temperature sensor circuit which is subject to severe
condensation. What's a good protective coating? I was thinking of
filling
the enclosure with silicone caulk, but I imagine some spray coating
might be
better?

Is it possible to have just the sensor in the condensing atmosphere?

Yes, but the non condensing atmosphere is outside, so then I've got
snow/ice/critters to worry about. The sensor measures the temperature of
an ornamental pond (coverered) and controls a heater to prevent
fishsicles.


If not, then you will need a small 'Hoffman Enclosure' with a NEMA (I
forget the #) rating.

If you use epoxy you may want to use marine epoxy, that's the stuff
they make boat hulls out of, available at boat shops. Also called
'West Epoxy'.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
Click to expand...
 
"Martin" <Martin@123.com> wrote

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the
touching of
the 10k Resistor to the 9volts turns the led on. If I connect it up
the way
the diagram shows me the LED just comes on and stays on. If I connect
the
10k to the 9v the light gets a little brighter.
Click to expand...
What if you connect the resistor to ground? The LED should turn off
then.

Presumably the problem is that I have the orientation wrong. But when
I look
at the data sheet I could swear I have it right. I'm afraid I find it
a
little confusing specially with the fact that it appears that there
are at
least 3 packages that look the same and have different pin outs eg.
TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d
diagram.
The diagram seems to show two double lines || || to indicate the
rounded
side of the transistor.(I assume) So looking at the transistor that
way the
orientation is ||EBC|| . (looking straight on rounded side pins down)
Click to expand...
You should be looking at the flat side, pins down for the EBC order.

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows
holding
the transistor by the pins. Legs down in front of me and with the flat
part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in
the air
with the flat part away from me C.B.E.
Click to expand...
No, pins down with flat side towards you (writing visible).
 
"Jamie" <jamie_5_not_valid_after_5_Please@charter.net> wrote in message
news:k%dBd.45125$VE2.19011@fe06.lga...
Martin wrote:

I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The
supply
voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to
include
the 10k resistor in the base connection or you will destroy the
transistor
as you test it!
If the transistor is OK the LED should light when the switch is pressed
and
not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and
the
supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the touching
of
the 10k Resistor to the 9volts turns the led on. If I connect it up the
way
the diagram shows me the LED just comes on and stays on. If I connect
the
10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I
look
at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are
at
least 3 packages that look the same and have different pin outs eg.
TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d
diagram.
The diagram seems to show two double lines || || to indicate the
rounded
side of the transistor.(I assume) So looking at the transistor that way
the
orientation is ||EBC|| . (looking straight on rounded side pins down)

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows
holding
the transistor by the pins. Legs down in front of me and with the flat
part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the
air
with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my
orientation,
and is the circuit for testing transistors wrong. It works in complete
reverse for me.



most of the time the lay outs are from the bottom
in other words, you look at the transistor upside down.
seeing that its a NTE, i wouldn't put it pass them to
use a different config for that number
the their replacements don't always match the physicals
of the original also, you must remember that most of their
replacements are nothing more than other transistors that
electrically replace but not always physically and includes
not matching their own case specs at times.
you can't trust NTE in many case, their replacements are not
always good depending on the application.

Jamie,
Click to expand...

Thanks for your points. By the way something strange is happening regarding
this post, I see your response but cannot see my question. It has not showed
up on the news group.????

Anyway your scaring me now. How the heck are we suppose to know how to
orient the transistors if the diagrams they give us on the packages are
wrong ??
Regards
 
"Anthony Fremont" <spam@anywhere.com> wrote in message
news:AeeBd.34848$wD4.6682@fe1.texas.rr.com...
"Martin" <Martin@123.com> wrote

Anyway your scaring me now. How the heck are we suppose to know how to
orient the transistors if the diagrams they give us on the packages
are
wrong ??

I think it's unlikely that the diagram on the package is wrong. The
other poster was just telling you to be wary of NTE cross-refs as the
pin-outs don't always match the original part.

What happens if you ground the base when hooked up as the schematic
shows (emitter to ground)? The LED should turn off.

Im at work right now and cant check that. However I will check that when I
Click to expand...
get home. As I mentioned right now based on the test the LED stays on and
gets a little brighter when I touch the base with the 10k to +. I will try
touching the base to ground and see if it goes out. If it does what does
that mean (if it does not what does it mean).
Thanks.
 
"Jamie" <jamie_5_not_valid_after_5_Please@charter.net> wrote in message
news:wqeBd.45131$QX2.30546@fe06.lga...
Martin wrote:
"Jamie" <jamie_5_not_valid_after_5_Please@charter.net> wrote in message
news:k%dBd.45125$VE2.19011@fe06.lga...

Martin wrote:


I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The

supply

voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to

include

the 10k resistor in the base connection or you will destroy the

transistor

as you test it!
If the transistor is OK the LED should light when the switch is pressed

and

not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and

the

supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the
touching

of

the 10k Resistor to the 9volts turns the led on. If I connect it up the

way

the diagram shows me the LED just comes on and stays on. If I connect

the

10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I

look

at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are

at

least 3 packages that look the same and have different pin outs eg.

TO92A,

TO92B, TO92C. I sort of wish that the data sheets would give a 3d

diagram.

The diagram seems to show two double lines || || to indicate the

rounded

side of the transistor.(I assume) So looking at the transistor that way

the

orientation is ||EBC|| . (looking straight on rounded side pins down)

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows

holding

the transistor by the pins. Legs down in front of me and with the flat

part

with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the

air

with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my

orientation,

and is the circuit for testing transistors wrong. It works in complete
reverse for me.




most of the time the lay outs are from the bottom
in other words, you look at the transistor upside down.
seeing that its a NTE, i wouldn't put it pass them to
use a different config for that number
the their replacements don't always match the physicals
of the original also, you must remember that most of their
replacements are nothing more than other transistors that
electrically replace but not always physically and includes
not matching their own case specs at times.
you can't trust NTE in many case, their replacements are not
always good depending on the application.


Jamie,

Thanks for your points. By the way something strange is happening
regarding
this post, I see your response but cannot see my question. It has not
showed
up on the news group.????

Anyway your scaring me now. How the heck are we suppose to know how to
orient the transistors if the diagrams they give us on the packages are
wrong ??
Regards


http://www.nteinc.com/graphics/diag9a.gif
if that will help you at all.
the top part of the image is the flat surface.

it is good double check for the base and emitter.
there is a simple way to test for the base and emitter if you
have variable voltage source , you inject + volts into what you
think is the emitter, and then place the + lead of your DMM on what
you think is the base.
most transistors will break down at a much lower point in the emitter
vs the base to the collect.
some common values are around 6 volts, the emitter become a zener
diode.
some times i see that using a DMM in Diode mode you can get a lower
forward reading on the BE side but don't depend on that..
you should have a DMM with a transistor checker on it.

James,
Click to expand...
The link you sent me is basically the same as the those provided by the
datasheet. Im afraid I dont understand your description "The top part of the
image is the flat surface" Are you saying that looking at the transistor
picture that you provided Im looking at the flat part of the transistor with
all the writing on it. If that is so then Ive been completely wrong on how
to read these pictures. In other words ||EBC|| <- Flat part of transistor
legs down.

On your test of the transistor using a DMM, When you put say 9 volts to what
you think is the emiter and then test the Base Im not sure what you mean by
"most transistors will break down at a much lower point" do you mean that I
will get a low Volt reading on the DMM at the base. And if I put 9volts to
the collector I will not get as much voltage loss.

Finally I do have a transistor testor in my volt meter. And while I have
searched to find some info on actually how to use it I cant find very much.
I know I am suppose to put in the transistors into the PNP or NPN side and
then orient the legs properly , but the numbers I get out of it dont seem to
relate to anything on the specs of the datasheets. Im at work right now and
so am going from memory, but last night I did test the transistors in my
tester both ways ebc and cbe. I cant remember the numbers I got ( I think
one was 93) I could not see however how this related to anything on the data
sheet.
Any advice or links on this would be helpfull.

Regards
 
"Anthony Fremont" <spam@anywhere.com> wrote in message
news:eek:leBd.34849$wD4.25465@fe1.texas.rr.com...
"Martin" <Martin@123.com> wrote

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the
touching of
the 10k Resistor to the 9volts turns the led on. If I connect it up
the way
the diagram shows me the LED just comes on and stays on. If I connect
the
10k to the 9v the light gets a little brighter.

What if you connect the resistor to ground? The LED should turn off
then.

Presumably the problem is that I have the orientation wrong. But when
I look
at the data sheet I could swear I have it right. I'm afraid I find it
a
little confusing specially with the fact that it appears that there
are at
least 3 packages that look the same and have different pin outs eg.
TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d
diagram.
The diagram seems to show two double lines || || to indicate the
rounded
side of the transistor.(I assume) So looking at the transistor that
way the
orientation is ||EBC|| . (looking straight on rounded side pins down)

You should be looking at the flat side, pins down for the EBC order.

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows
holding
the transistor by the pins. Legs down in front of me and with the flat
part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in
the air
with the flat part away from me C.B.E.

No, pins down with flat side towards you (writing visible).


Well that explains a lot. It appears I have been looking at the diagrams
Click to expand...
incorectly. grrr.

Thanks.
 
Martin wrote:

I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The supply
voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to include
the 10k resistor in the base connection or you will destroy the transistor
as you test it!
If the transistor is OK the LED should light when the switch is pressed and
not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and the
supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the touching of
the 10k Resistor to the 9volts turns the led on. If I connect it up the way
the diagram shows me the LED just comes on and stays on. If I connect the
10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I look
at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are at
least 3 packages that look the same and have different pin outs eg. TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d diagram.
The diagram seems to show two double lines || || to indicate the rounded
side of the transistor.(I assume) So looking at the transistor that way the
orientation is ||EBC|| . (looking straight on rounded side pins down)

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows holding
the transistor by the pins. Legs down in front of me and with the flat part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the air
with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my orientation,
and is the circuit for testing transistors wrong. It works in complete
reverse for me.



most of the time the lay outs are from the bottom
Click to expand...
in other words, you look at the transistor upside down.
seeing that its a NTE, i wouldn't put it pass them to
use a different config for that number
the their replacements don't always match the physicals
of the original also, you must remember that most of their
replacements are nothing more than other transistors that
electrically replace but not always physically and includes
not matching their own case specs at times.
you can't trust NTE in many case, their replacements are not
always good depending on the application.
 
On Fri, 31 Dec 2004 09:38:09 -0600, "Martin" <Martin@123.com> wrote:

I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The supply
voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to include
the 10k resistor in the base connection or you will destroy the transistor
as you test it!
If the transistor is OK the LED should light when the switch is pressed and
not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and the
supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the touching of
the 10k Resistor to the 9volts turns the led on. If I connect it up the way
the diagram shows me the LED just comes on and stays on. If I connect the
10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I look
at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are at
least 3 packages that look the same and have different pin outs eg. TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d diagram.
The diagram seems to show two double lines || || to indicate the rounded
side of the transistor.(I assume) So looking at the transistor that way the
orientation is ||EBC|| . (looking straight on rounded side pins down)
Click to expand...
---
There's the problem!

The two solid lines on the far left and right of the diagram indicate
the edges of the package while the two inner lines indicate the edges
of the flat. looking at it with the flat _facing_ you. If the flat
were on the far side, the inner lines would be dashed. That's an old
drafting convention which is used to show hidden lines. Another
convention is to visualize a drawing as lying on the bottom of a bowl,
and when the view changes, you slide the old view up the side of the
bowl until it becomes the new view.

So, looking at the NTE108 drawing in that light, the topmost view is
that of a TO-92 package with the flat facing you and the leads
pointing down, the lead order being EBC from left to right. Then, if
you push that view down it'll slide up the wall of the bowl and you'll
wind up with a bottom view of the package with the lead sequence still
being EBC from left to right.
---

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows holding
the transistor by the pins. Legs down in front of me and with the flat part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the air
with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my orientation,
and is the circuit for testing transistors wrong. It works in complete
reverse for me.
Click to expand...
---
The circuit is OK, and as you noticed, if you have the transistor
connected into the circuit CBE instead of EBC, the LED will stay on
all the time if the battery voltage is > about 6 or 7 volts or so
because you're breaking down the base-to-emitter diode. Not a good
thing to do, but a good way to tell if you've got the transistor in
backwards or, if that happens and you connect reverse the collector
and emitter and it continues to light up, you've got a collector-to-
emitter short.

--
John Fields
 
Martin wrote:
"Jamie" <jamie_5_not_valid_after_5_Please@charter.net> wrote in message
news:k%dBd.45125$VE2.19011@fe06.lga...

Martin wrote:


I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The

supply

voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to

include

the 10k resistor in the base connection or you will destroy the

transistor

as you test it!
If the transistor is OK the LED should light when the switch is pressed

and

not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and

the

supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the touching

of

the 10k Resistor to the 9volts turns the led on. If I connect it up the

way

the diagram shows me the LED just comes on and stays on. If I connect

the

10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I

look

at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are

at

least 3 packages that look the same and have different pin outs eg.

TO92A,

TO92B, TO92C. I sort of wish that the data sheets would give a 3d

diagram.

The diagram seems to show two double lines || || to indicate the

rounded

side of the transistor.(I assume) So looking at the transistor that way

the

orientation is ||EBC|| . (looking straight on rounded side pins down)

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows

holding

the transistor by the pins. Legs down in front of me and with the flat

part

with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the

air

with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my

orientation,

and is the circuit for testing transistors wrong. It works in complete
reverse for me.




most of the time the lay outs are from the bottom
in other words, you look at the transistor upside down.
seeing that its a NTE, i wouldn't put it pass them to
use a different config for that number
the their replacements don't always match the physicals
of the original also, you must remember that most of their
replacements are nothing more than other transistors that
electrically replace but not always physically and includes
not matching their own case specs at times.
you can't trust NTE in many case, their replacements are not
always good depending on the application.


Jamie,

Thanks for your points. By the way something strange is happening regarding
this post, I see your response but cannot see my question. It has not showed
up on the news group.????

Anyway your scaring me now. How the heck are we suppose to know how to
orient the transistors if the diagrams they give us on the packages are
wrong ??
Regards


http://www.nteinc.com/graphics/diag9a.gif
Click to expand...
if that will help you at all.
the top part of the image is the flat surface.

it is good double check for the base and emitter.
there is a simple way to test for the base and emitter if you
have variable voltage source , you inject + volts into what you
think is the emitter, and then place the + lead of your DMM on what
you think is the base.
most transistors will break down at a much lower point in the emitter
vs the base to the collect.
some common values are around 6 volts, the emitter become a zener diode.
some times i see that using a DMM in Diode mode you can get a lower
forward reading on the BE side but don't depend on that..
you should have a DMM with a transistor checker on it.
 
"Art" <plotsligt@comcast.net> wrote in message
news:TqKdnSdZgeUzp0jcRVn-oQ@comcast.com...
Maybe Bee's Wax?? Seriously, melted Bee's Wax applied over the item, it
will not affect the ability to sense temperature changes as long as the
ambient does not exceed the melting temp of the wax. I presume the sensor
is immersed in the pond, water covered?? IMHO
Click to expand...
Thanks Art,

I think someone else suggested wax too. Yes, the sensor (LM34) is at the end
of a cable, covered in "connector coating". Seems to be similar to
Plastidip. The sensor is in the water and the board/case is attached to the
bottom of the pond cover's escape hatch. Water temp is around 40°F and the
outside air (above cover) can be as low as -40°F. Although we haven't seen
that yet.

I removed the circuit (board/case/sesnor) this morning. The solder side of
the board, which rests against the case lid, was dripping in water. The
component side seems almost completely dry. Once I dried the circuit out
again, it started to work fine. On the bright side, all that water
emulsified the flux residue. Making my coating job much easier.

I bought some Acrylic spray for my coating, they didn't have the dip. I may
also put some Silicone in the case lid to be safe.
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:fg1bt0le4k6ph1f640155df7104qlkpt2s@4ax.com...
On Fri, 31 Dec 2004 09:38:09 -0600, "Martin" <Martin@123.com> wrote:

I'm a novice.

I'm trying to test NTE108 transistor.
I found a little circuit that is suppose to test transistors.
See diagram below or link.



http://www.kpsec.freeuk.com/components/tran.htm
The description of its use is as follows...
Testing in a simple switching circuit Connect the transistor into the
circuit shown on the right which uses the transistor as a switch. The
supply
voltage is not critical, anything between 5 and 12V is suitable. This
circuit can be quickly built on breadboard for example. Take care to
include
the 10k resistor in the base connection or you will destroy the
transistor
as you test it!
If the transistor is OK the LED should light when the switch is pressed
and
not light when the switch is released.

To test a PNP transistor use the same circuit but reverse the LED and the
supply voltage.

--------------------

The problem is that when I try to test my 108 it seems to work in the
reverse. That is when Emitter is on C and Collector is on E the touching
of
the 10k Resistor to the 9volts turns the led on. If I connect it up the
way
the diagram shows me the LED just comes on and stays on. If I connect the
10k to the 9v the light gets a little brighter.

Presumably the problem is that I have the orientation wrong. But when I
look
at the data sheet I could swear I have it right. I'm afraid I find it a
little confusing specially with the fact that it appears that there are
at
least 3 packages that look the same and have different pin outs eg.
TO92A,
TO92B, TO92C. I sort of wish that the data sheets would give a 3d
diagram.
The diagram seems to show two double lines || || to indicate the rounded
side of the transistor.(I assume) So looking at the transistor that way
the
orientation is ||EBC|| . (looking straight on rounded side pins down)

---
There's the problem!

The two solid lines on the far left and right of the diagram indicate
the edges of the package while the two inner lines indicate the edges
of the flat. looking at it with the flat _facing_ you. If the flat
were on the far side, the inner lines would be dashed. That's an old
drafting convention which is used to show hidden lines. Another
convention is to visualize a drawing as lying on the bottom of a bowl,
and when the view changes, you slide the old view up the side of the
bowl until it becomes the new view.

So, looking at the NTE108 drawing in that light, the topmost view is
that of a TO-92 package with the flat facing you and the leads
pointing down, the lead order being EBC from left to right. Then, if
you push that view down it'll slide up the wall of the bowl and you'll
wind up with a bottom view of the package with the lead sequence still
being EBC from left to right.
---

Thus I think mine the NTE-108 T-NPN SI RF/IF/VID AMP is as follows
holding
the transistor by the pins. Legs down in front of me and with the flat
part
with the writing away from me and the round part toward me E B C. or
looking straight down at the transistor and the pins sticking up in the
air
with the flat part away from me C.B.E.

Can anyone point me in the right direction. Am I wrong in my orientation,
and is the circuit for testing transistors wrong. It works in complete
reverse for me.

---
The circuit is OK, and as you noticed, if you have the transistor
connected into the circuit CBE instead of EBC, the LED will stay on
all the time if the battery voltage is > about 6 or 7 volts or so
because you're breaking down the base-to-emitter diode. Not a good
thing to do, but a good way to tell if you've got the transistor in
backwards or, if that happens and you connect reverse the collector
and emitter and it continues to light up, you've got a collector-to-
emitter short.

--
John Fields
Click to expand...
Thanks. for the info. Indeed I suppose the little tester I build was telling
me the truth. And at least tigged me to the fact that something I was doing
was wrong. Frankly while the drafting idea of dashes makes complete sense
(NOW), I didnt see anywhere that explained the proper orientation of the ||
|| double lines. Your explanation provides this and it makes sense that you
would read it from the flat side that has writing on it.

Thanks.
 
"Bill Stock" <Me7@Privacy.net> wrote

[Fish pond heater for the winter ... exposed PCB
... dripping water ... etc. ]
Click to expand...
There were completely submersible fish tank heaters - two
test-tubes IIRC, one with a heater and one with a fixed thermostat,
wired together and to a line cord. The test-tubes were sealed at
the top with some green gunk. Heating element was packed in sand
inside the test-tube.

Might this sort of construction be applicable?

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
>
 
"Nicholas O. Lindan" <see@sig.com> wrote in message
news:3hjBd.8482$qf5.2100@newsread3.news.atl.earthlink.net...
"Bill Stock" <Me7@Privacy.net> wrote

[Fish pond heater for the winter ... exposed PCB
... dripping water ... etc. ]
Click to expand...
PVB is inside a case. Now conformal coated.

There were completely submersible fish tank heaters - two
test-tubes IIRC, one with a heater and one with a fixed thermostat,
wired together and to a line cord. The test-tubes were sealed at
the top with some green gunk. Heating element was packed in sand
inside the test-tube.

Might this sort of construction be applicable?
Click to expand...
I'm using a titanium aquarium heater to do the heating. But it's thermostat
starts at 68°F. My goal is to keep the bottom of the pond around 39°F (max
density of water). This should prevent too much convection and be much
cheaper to heat. These heaters aren't designed for prolonged use, they will
burn out quickly. Right now it only runs about 10 minutes per day, depending
on outside temp and snow coverage (insulation). The sensor is also hooked
into the house's automation system, so I can monitor any problems.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
Click to expand...
 
(oookhc@hotmail.com) writes:
You might try to start with

http://www.ScienceOxygen.com/idea.html

It does not give you step-by-step instruction; it is just a
collection of links about science ideas. Probably you can
have some new ideas from that...
Click to expand...
Well kid, you're replying to a thread that started in April of 1999,
and which only lasted a few posts. The original poster is bound to be
long gone by now, indeed is now about 21 and long graduated from high school.

You compound your error of replying to an almost six year old thread by not
quoting what you are replying to. Nobody has a clue what you are talking
about, and people are scratching their heads wondering where the post
you are replying to is.

The only reason I know, and I'm not the only one, is because this responding
to long-dead threads has become common in the past month since google
"remodelled" itself and made the mistake of letting people reply to old
threads, so I went to google and immediately verified that my guess was
right and you were replying to a really old message.

Just because google is an archive that lets people see messages going back
to the beginnings of the newsgroups in 1979 or so does not mean it's a good
thing to reply to old messages. And just because when you use the
archive to see old messages you see the full thread does not mean that
many or most people view the threads that way. Google is merely an archive
of newsgroups; the newsgroups go back a quarter century but google has
only been keeping the archives since a few years back. They want you to
think you've just posted to one of their "groups" but that's not how it
works. If you don't understand this, you shouldn't be posting from
there.

Micahel
 
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