Chip with simple program for Toy

[Phil Hobbs]

On 2/3/2013 1:41 AM, John Doe wrote:

"Tim Williams" <tmoranwms charter.net> wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so they don't know if the scene is moving, only if the average
IR changes.

That's all I want. It's not going to be the only part of the
system, and I can interpret the output. I guess it could even be a
very short (1 second or less) on time by a common passive infrared
motion detector, so that it would flash during its detection time.

I don't know about this particular sensor, but most of the commercial
PIR elements for porch lights have the FET built in. Maybe the 47k is
the source resistor of the JFET follower?

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[John Doe]

"Tim Williams" <tmoranwms charter.net> wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so they don't know if the scene is moving, only if the average
IR changes.

That's all I want. It's not going to be the only part of the
system, and I can interpret the output. I guess it could even be a
very short (1 second or less) on time by a common passive infrared
motion detector, so that it would flash during its detection time.

 

[harry]

On Feb 3, 3:28 am, John Doe <j...@usenetlove.invalid> wrote:

Correct me if I'm wrong on any of this, but... The motion sensor
(part) output constantly varies. Only when its output reaches a
certain level relative to its normal state, then it trips a switch
that drives the light for some period of time. Then the lightbulb
switches off and waits for another significant change in
detection.

What I would like to do is have a lightbulb or LED
brightness/intensity follow the motion sensor output part. In
other words... If a bird flies by, the lightbulb would momentarily
dimly light. If a person walks into close range, the lightbulb
would continuously shine brightly. If the person walked behind
some object, the lightbulb would go off, and then when they
reappeared, the lightbulb would come back on. Hopefully I'm not
over describing this, but I'll be happy to provide more
description if asked.

Does such a device (or close) already exist for purchase in a
store?

The sensor output part typically could not be connected to an LED
without putting an amplifier on it? Anybody do this before, any
schematic?

Thanks.

--
Crossposted, feel free to delete the other group(s).
BTW. I'm not suggesting that anybody else could use or enjoy this.

You can buy sensors that have a restricted/adjustable "target" size.
To eliminate nuisance operations from small animals.

There will always be an amplifier and relay in the circuit.

 

[trader4@optonline.net]

On Feb 3, 1:55 am, Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net>
wrote:

On 2/3/2013 1:41 AM, John Doe wrote:

"Tim Williams" <tmoranwms charter.net> wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so they don't know if the scene is moving, only if the average
IR changes.

That's all I want. It's not going to be the only part of the
system, and I can interpret the output. I guess it could even be a
very short (1 second or less) on time by a common passive infrared
motion detector, so that it would flash during its detection time.

I don't know about this particular sensor, but most of the commercial
PIR elements for porch lights have the FET built in.  Maybe the 47k is
the source resistor of the JFET follower?

Cheers

Phil Hobbs

I doubt he's going to find a finished product that does what
he wants. The products ready to be mounted have not
only the sensor, but as he points, out the circuitry that
turns it into some kind of on/off output that is needed for
the product.

However those motion detector products use ICs which
he can probably find. Some of the ICs provide an analog
output that he could use together with his own circuit.
Here are examples from one company:

http://www.mouser.com/ds/2/281/s21e-6137.pdf

 

[trader4@optonline.net]

On Feb 3, 3:05 am, harry <harry130...@btinternet.com> wrote:

On Feb 3, 3:28 am, John Doe <j...@usenetlove.invalid> wrote:





Correct me if I'm wrong on any of this, but... The motion sensor
(part) output constantly varies. Only when its output reaches a
certain level relative to its normal state, then it trips a switch
that drives the light for some period of time. Then the lightbulb
switches off and waits for another significant change in
detection.

What I would like to do is have a lightbulb or LED
brightness/intensity follow the motion sensor output part. In
other words... If a bird flies by, the lightbulb would momentarily
dimly light. If a person walks into close range, the lightbulb
would continuously shine brightly. If the person walked behind
some object, the lightbulb would go off, and then when they
reappeared, the lightbulb would come back on. Hopefully I'm not
over describing this, but I'll be happy to provide more
description if asked.

Does such a device (or close) already exist for purchase in a
store?

The sensor output part typically could not be connected to an LED
without putting an amplifier on it? Anybody do this before, any
schematic?

Thanks.

--
Crossposted, feel free to delete the other group(s).
BTW. I'm not suggesting that anybody else could use or enjoy this.

You can buy sensors that have a restricted/adjustable  "target" size.
To eliminate nuisance operations from small animals.

There will always be an amplifier and relay in the circuit.- Hide quoted text -

- Show quoted text -

Wrong yet again. harry is like a cosmic black hole of ignorance, no
real knowledge can exist anywhere near him.

 

[Phil Hobbs]

On 2/3/2013 9:16 AM, trader4@optonline.net wrote:

On Feb 3, 1:55 am, Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net
wrote:
On 2/3/2013 1:41 AM, John Doe wrote:

"Tim Williams" <tmoranwms charter.net> wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so they don't know if the scene is moving, only if the average
IR changes.

That's all I want. It's not going to be the only part of the
system, and I can interpret the output. I guess it could even be a
very short (1 second or less) on time by a common passive infrared
motion detector, so that it would flash during its detection time.

I don't know about this particular sensor, but most of the commercial
PIR elements for porch lights have the FET built in. Maybe the 47k is
the source resistor of the JFET follower?

Cheers

Phil Hobbs



I doubt he's going to find a finished product that does what
he wants. The products ready to be mounted have not
only the sensor, but as he points, out the circuitry that
turns it into some kind of on/off output that is needed for
the product.

However those motion detector products use ICs which
he can probably find. Some of the ICs provide an analog
output that he could use together with his own circuit.
Here are examples from one company:

http://www.mouser.com/ds/2/281/s21e-6137.pdf

On Page 3 of that brochure there's a schematic like the one I'm talking
about--the sensor load resistor is inside the capsule, and the external
resistor is the source load for the JFET follower. That's the usual
approach IME.

Porch light sensors are actually pretty cool devices--they use a split
pyroelectric sensor, with the two halves wired opposing each other. A
segmented Fresnel lens casts a dozen or so images of the scene, so as
you walk up to the door, a dozen of you cross the sensor, causing about
a 10- or 12- cycle AC waveform, which is detected with a comparator.

The split cell makes the sensor much more resistant to changes in
ambient temperature, power supply voltage, and that sort of stuff. A
cute design--whoever came up with it should be better known.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[Jamie]

Tim Williams wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing, so they
don't know if the scene is moving, only if the average IR changes.
Which it does when someone comes into view or jumps out of the shadows,
but it doesn't do jack if someone walks around freely while holding up a
room-temperature blanket, or moves in the scene while presenting an
equal viewing cross section (probably tricky to do).

The output is positive or negative charge, corresponding to the change
in temperature viewed. Into a high resistive load (say, like something
Phil might be working on right now ), this has a time constant (the
sensor's just an insulating crystal), so it automatically centers after
a while. In other words, it's a temperature differentiator (for
pedants, that's the RC kind). Obviously, a motion detector needs only a
window comparator; you could use a suitably calibrated gain instead
(followed by a full-wave active rectifier), and maybe a lowpass, or
falling slew rate limiter, to enhance the effect.

Still might not be quite as intended; if the detector response is equal
across the viewing angle, then a person walking across the path will
cause it to light up (or down), then not do so much (depending on how
the sensor sees a walking body), then light up again on leaving the frame.

Tim

we used a few of those for wire break and jerk detectors just as the
conductor comes out of the induction heater and prior to entering the
extrusion head assembly.

Since the conductor will jerk with a over sized section going through
or a breakage, it works out well. There is also a small air jet that
sits infront of the IR passive glass to keep the dust off.

Jamie

 

[SoothSayer]

On Sun, 03 Feb 2013 01:55:03 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2/3/2013 1:41 AM, John Doe wrote:
"Tim Williams" <tmoranwms charter.net> wrote:

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so they don't know if the scene is moving, only if the average
IR changes.

That's all I want. It's not going to be the only part of the
system, and I can interpret the output. I guess it could even be a
very short (1 second or less) on time by a common passive infrared
motion detector, so that it would flash during its detection time.


I don't know about this particular sensor, but most of the commercial
PIR elements for porch lights have the FET built in. Maybe the 47k is
the source resistor of the JFET follower?

Cheers

Phil Hobbs

One must also be *VERY* careful when handling/installing the device as
well. They usually come with shorting wires on the leads they are so
worried.

Some FETs can be blown by an ESD field, particularly prior to being
installed. Does not even require contact.

That is why a smock is required at the 'proper' ESD safe workstation.
It 'contains' whatever fields you and your insulative clothing may be
carrying.

 

[John Fields]

On Sun, 3 Feb 2013 03:28:58 +0000 (UTC), John Doe
<jdoe@usenetlove.invalid> wrote:

Correct me if I'm wrong on any of this, but... The motion sensor
(part) output constantly varies.

---
Generally, no.

The common pyroelectric motion sensor outputs a single pulse when the
incident radiation which falls on the detector has a higher or lower
wavelength than that of the ambient radiation within the field of view
of the transducer.
---

Only when its output reaches a
certain level relative to its normal state, then it trips a switch
that drives the light for some period of time. Then the lightbulb
switches off and waits for another significant change in
detection.

---
All true, but since it's only the rate of change of amplitude of the
pulse - which goes with the velocity of the target - which drives the
switch, there's no range information to be gleaned.

There are sensor arrays available with multiple transducers.

Knowing, then, the focal length of the lens, the distance between the
transducers and the difference in time between the responses of the
transducers, the range to the target can be calculated.
---

What I would like to do is have a lightbulb or LED
brightness/intensity follow the motion sensor output part. In
other words... If a bird flies by, the lightbulb would momentarily
dimly light. If a person walks into close range, the lightbulb
would continuously shine brightly. If the person walked behind
some object, the lightbulb would go off, and then when they
reappeared, the lightbulb would come back on. Hopefully I'm not
over describing this, but I'll be happy to provide more
description if asked.

Does such a device (or close) already exist for purchase in a
store?

---
Someone already mentioned a TOF SONAR sensor, which would be ideal if
it could resolve distance to the accuracy you require, which will vary
depending on temperature, humidity, and atmospheric pressure.

Can you address that?
---

The sensor output part typically could not be connected to an LED
without putting an amplifier on it? Anybody do this before, any
schematic?

Thanks.
--

JF

 

[John Doe]

John Fields <jfields austininstruments.com> wrote:

John Doe <jdoe usenetlove.invalid> wrote:

Correct me if I'm wrong on any of this, but... The motion sensor
(part) output constantly varies.

Generally, no.

The common pyroelectric motion sensor outputs a single pulse
when the incident radiation which falls on the detector has a
higher or lower wavelength than that of the ambient radiation
within the field of view of the transducer.

I guess that means there is no analog output. So it's not like a
photo resistor. I've played with photo resistors, controlling a
variable frequency connected to a speaker. Aiming it towards a TV
produced amusing and rapidly changing frequencies. I wonder if
there are hypersensitive photo resistors that might do (with a
wide field of view), maybe infrared or whatever. Or maybe that has
already been suggested under different terminology.

Someone already mentioned a TOF SONAR sensor, which would be
ideal if it could resolve distance to the accuracy you require,
which will vary depending on temperature, humidity, and
atmospheric pressure.

Can you address that?

I don't need to know distance or speed. All I want to sense is
changes in radiation in the area. But if the changes in intensity
are great, that might suggest the object is either large or
nearby. I guess that would be a function of something like a
long-range omnidirectional (or wide angle, as long as it's view is
not narrow) infrared photo resistor/sensor if there is such a
thing. I'll look.

Distance to sense a person, to noticeably and distinctly change
the output, needs to be at least 20 feet, preferably 50-100.




--
Thanks to the replies.

 

[John Fields]

On Mon, 4 Feb 2013 03:05:37 +0000 (UTC), John Doe
<jdoe@usenetlove.invalid> wrote:

To be clear...
actually, what I played with might be called a photodiode (not a
photoresistor), it looked like an ordinary white LED, it didn't have
the squiggly wires inside

---
Then it's more than likely either a photodiode or a phototransistor.

Can you post a schematic of the circuit you played with?

--
JF

 

[John Fields]

On Mon, 4 Feb 2013 01:51:54 +0000 (UTC), John Doe
<jdoe@usenetlove.invalid> wrote:

John Fields <jfields austininstruments.com> wrote:

John Doe <jdoe usenetlove.invalid> wrote:

Correct me if I'm wrong on any of this, but... The motion sensor
(part) output constantly varies.

Generally, no.

The common pyroelectric motion sensor outputs a single pulse
when the incident radiation which falls on the detector has a
higher or lower wavelength than that of the ambient radiation
within the field of view of the transducer.

I guess that means there is no analog output. So it's not like a
photo resistor. I've played with photo resistors, controlling a
variable frequency connected to a speaker. Aiming it towards a TV
produced amusing and rapidly changing frequencies. I wonder if
there are hypersensitive photo resistors that might do (with a
wide field of view), maybe infrared or whatever. Or maybe that has
already been suggested under different terminology.

Someone already mentioned a TOF SONAR sensor, which would be
ideal if it could resolve distance to the accuracy you require,
which will vary depending on temperature, humidity, and
atmospheric pressure.

Can you address that?

I don't need to know distance or speed. All I want to sense is
changes in radiation in the area. But if the changes in intensity
are great, that might suggest the object is either large or
nearby. I guess that would be a function of something like a
long-range omnidirectional (or wide angle, as long as it's view is
not narrow) infrared photo resistor/sensor if there is such a
thing. I'll look.

Distance to sense a person, to noticeably and distinctly change
the output, needs to be at least 20 feet, preferably 50-100.

---
I've done long-range PIR detection before and 20 feet is pretty easy,
but 100 feet is going to take some care.

Can you tell us a little more about your application?

--
JF

 

[John Fields]

On Mon, 4 Feb 2013 23:35:40 +0000 (UTC), John Doe
<jdoe@usenetlove.invalid> wrote:

John Fields <jfields austininstruments.com> wrote:

John Doe <jdoe usenetlove.invalid> wrote:

To be clear... actually, what I played with might be called a
photodiode (not a photoresistor), it looked like an ordinary
white [clear] LED, it didn't have the squiggly wires inside

Then it's more than likely either a photodiode or a
phototransistor.

Can you post a schematic of the circuit you played with?

Google produces 280 results for my "Tonal Voltmeter". I'm sure it
was just that, using a photodiode to vary resistance/voltage. It
looked like a clear T1 LED. I have nothing left (except fond
memories) from experimenting with electronics.

---
eternalseptember.org, huh?

Bye.

--
JF

 

[John Doe]

John Fields <jfields austininstruments.com> wrote:

John Doe <jdoe usenetlove.invalid> wrote:

To be clear... actually, what I played with might be called a
photodiode (not a photoresistor), it looked like an ordinary
white [clear] LED, it didn't have the squiggly wires inside

Then it's more than likely either a photodiode or a
phototransistor.

Can you post a schematic of the circuit you played with?

Google produces 280 results for my "Tonal Voltmeter". I'm sure it
was just that, using a photodiode to vary resistance/voltage. It
looked like a clear T1 LED. I have nothing left (except fond
memories) from experimenting with electronics.

 

[John Doe]

John Fields <jfields austininstruments.com> wrote:

John Doe <jdoe usenetlove.invalid> wrote:
John Fields <jfields austininstruments.com> wrote:
John Doe <jdoe usenetlove.invalid> wrote:

To be clear... actually, what I played with might be called a
photodiode (not a photoresistor), it looked like an ordinary
white [clear] LED, it didn't have the squiggly wires inside

Then it's more than likely either a photodiode or a
phototransistor.

Can you post a schematic of the circuit you played with?

Google produces 280 results for my "Tonal Voltmeter". I'm sure
it was just that, using a photodiode to vary resistance/voltage.
It looked like a clear T1 LED. I have nothing left (except fond
memories) from experimenting with electronics.

--- eternalseptember.org, huh?

Yes?

As I said in two prior separate replies... I am FWIW satisfied
with the discussion. I will probably use a cheap motion detector,
and maybe try to shorten the on-time so that the light blinks
while motion is being sensed.

--

Bye.

--
JF



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Subject: Re: A different kind of motion sensing security light?
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[John Fields]

On Fri, 8 Feb 2013 22:16:55 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
newsptah8t3j72uqpv442dj09supt25l4npcc@4ax.com...
On Thu, 7 Feb 2013 22:05:17 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:9d58h81gtrnkd2dm9ii3pi1cfn3h51ul04@4ax.com...
On Thu, 7 Feb 2013 20:54:23 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:2f55h8hgb34k7dk6bki11g1kee742avbuj@4ax.com...
On Wed, 6 Feb 2013 16:42:04 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
message
news:j_gQs.69570$H5.27293@newsfe28.iad...
Ian Field wrote:



"Tim Williams" <tmoranwms@charter.net> wrote in message
news:keku69$6s1$1@dont-email.me...

AFAIK, pyroelectric sensors are a "single pixel" sort of thing, so
they
don't know if the scene is moving, only if the average IR changes.
Which it does when someone comes into view or jumps out of the
shadows,


If you mean PIR motion detectors, they usually have twin element
pyrometers (thin film thermistor) a motion of a IR source (person)
is
"grated" to produce a gross change from one element to the other -
this
is done in various ways such as Freznel type lenses (special IR
transparent material) and faceted surface reflecting reflectors.

That's strange that you would call them thermistors? TO me a
thermistor
is a slow reacting device?

I have some continuity/voltage checkers with a thin film PTC in series
with
an inverse parallel pair of high efficiency LEDs (2mA rating) - the
series
PTC thermistor can react fast enough to protect the LEDs from
application
to
voltages upto 450V.

---
Apples and oranges.

Your usual disingenuous self!

My point is that a thin film thermistor can have a very fast response
time -
there was no need to be specific exactly what material the thin film
was.

---
Identifying the materials was necessary in order to show you that
PTC's can't be PIR sensors, and vice versa.

Whether a thin-film PTC thermistor can have a very fast response time
is irrelevant when the discussion is about PIR sensors so, as usual,
you're befuddled.

On the one hand, consider the PTC thermistor you described and, on the
other, a PIR sensor.

The PTC thermistor is designed to have its resistance increase
spectacularly as it self-heats because of small changes in the current
through it, while the PIR sensor is designed to generate a miniscule
charge when the temperatures its elements are exposed to change
abruptly, ergo apples and oranges.


Wriggle wriggle!

---
In which way?

Any which way it takes when caught out.

---
I merely point out your errors, and since you were caught out as not
knowing the difference between a thin-film thermistor and a PIR sensor
and not knowing that a Fresnel lens isn't just for use with IR, it
seems you're the one doing all the wriggling when what you should be
doing is thanking me for smartening you up a bit.

--
JF

 

[Ian Field]

"John Fields" <jfields@austininstruments.com> wrote in message
newsoubh85q6ulf4chg9smt9qo9dk1iluk09s@4ax.com...

On Fri, 8 Feb 2013 22:16:55 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
newsptah8t3j72uqpv442dj09supt25l4npcc@4ax.com...
On Thu, 7 Feb 2013 22:05:17 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:9d58h81gtrnkd2dm9ii3pi1cfn3h51ul04@4ax.com...
On Thu, 7 Feb 2013 20:54:23 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:2f55h8hgb34k7dk6bki11g1kee742avbuj@4ax.com...
On Wed, 6 Feb 2013 16:42:04 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
message
news:j_gQs.69570$H5.27293@newsfe28.iad...
Ian Field wrote:



"Tim Williams" <tmoranwms@charter.net> wrote in message
news:keku69$6s1$1@dont-email.me...

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so
they
don't know if the scene is moving, only if the average IR
changes.
Which it does when someone comes into view or jumps out of the
shadows,


If you mean PIR motion detectors, they usually have twin element
pyrometers (thin film thermistor) a motion of a IR source
(person)
is
"grated" to produce a gross change from one element to the
other -
this
is done in various ways such as Freznel type lenses (special IR
transparent material) and faceted surface reflecting reflectors.

That's strange that you would call them thermistors? TO me a
thermistor
is a slow reacting device?

I have some continuity/voltage checkers with a thin film PTC in
series
with
an inverse parallel pair of high efficiency LEDs (2mA rating) - the
series
PTC thermistor can react fast enough to protect the LEDs from
application
to
voltages upto 450V.

---
Apples and oranges.

Your usual disingenuous self!

My point is that a thin film thermistor can have a very fast response
time -
there was no need to be specific exactly what material the thin film
was.

---
Identifying the materials was necessary in order to show you that
PTC's can't be PIR sensors, and vice versa.

Whether a thin-film PTC thermistor can have a very fast response time
is irrelevant when the discussion is about PIR sensors so, as usual,
you're befuddled.

On the one hand, consider the PTC thermistor you described and, on the
other, a PIR sensor.

The PTC thermistor is designed to have its resistance increase
spectacularly as it self-heats because of small changes in the current
through it, while the PIR sensor is designed to generate a miniscule
charge when the temperatures its elements are exposed to change
abruptly, ergo apples and oranges.


Wriggle wriggle!

---
In which way?

Any which way it takes when caught out.

---
I merely point out your errors, and since you were caught out as not
knowing the difference between a thin-film thermistor and a PIR sensor

They can both be thin film - a point you're too thick to get!

and not knowing that a Fresnel lens isn't just for use with IR

This is a copy/paste of what I typed: " Freznel type lenses (special IR

transparent material) "

Being "Freznel type lenses" they're obviously based on something that
existed before PIR sensors. - the more you wriggle - the more you have to be
disingenuous about what I actually said.

You're even too thick to snip what I actually said, so everyone can see
you're making it up the things I never said!

 

[John Fields]

On Sat, 9 Feb 2013 14:49:03 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
newsoubh85q6ulf4chg9smt9qo9dk1iluk09s@4ax.com...
On Fri, 8 Feb 2013 22:16:55 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
newsptah8t3j72uqpv442dj09supt25l4npcc@4ax.com...
On Thu, 7 Feb 2013 22:05:17 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:9d58h81gtrnkd2dm9ii3pi1cfn3h51ul04@4ax.com...
On Thu, 7 Feb 2013 20:54:23 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:2f55h8hgb34k7dk6bki11g1kee742avbuj@4ax.com...
On Wed, 6 Feb 2013 16:42:04 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
message
news:j_gQs.69570$H5.27293@newsfe28.iad...
Ian Field wrote:



"Tim Williams" <tmoranwms@charter.net> wrote in message
news:keku69$6s1$1@dont-email.me...

AFAIK, pyroelectric sensors are a "single pixel" sort of thing,
so
they
don't know if the scene is moving, only if the average IR
changes.
Which it does when someone comes into view or jumps out of the
shadows,


If you mean PIR motion detectors, they usually have twin element
pyrometers (thin film thermistor) a motion of a IR source
(person)
is
"grated" to produce a gross change from one element to the
other -
this
is done in various ways such as Freznel type lenses (special IR
transparent material) and faceted surface reflecting reflectors.

That's strange that you would call them thermistors? TO me a
thermistor
is a slow reacting device?

I have some continuity/voltage checkers with a thin film PTC in
series
with
an inverse parallel pair of high efficiency LEDs (2mA rating) - the
series
PTC thermistor can react fast enough to protect the LEDs from
application
to
voltages upto 450V.

---
Apples and oranges.

Your usual disingenuous self!

My point is that a thin film thermistor can have a very fast response
time -
there was no need to be specific exactly what material the thin film
was.

---
Identifying the materials was necessary in order to show you that
PTC's can't be PIR sensors, and vice versa.

Whether a thin-film PTC thermistor can have a very fast response time
is irrelevant when the discussion is about PIR sensors so, as usual,
you're befuddled.

On the one hand, consider the PTC thermistor you described and, on the
other, a PIR sensor.

The PTC thermistor is designed to have its resistance increase
spectacularly as it self-heats because of small changes in the current
through it, while the PIR sensor is designed to generate a miniscule
charge when the temperatures its elements are exposed to change
abruptly, ergo apples and oranges.


Wriggle wriggle!

---
In which way?

Any which way it takes when caught out.

---
I merely point out your errors, and since you were caught out as not
knowing the difference between a thin-film thermistor and a PIR sensor

They can both be thin film - a point you're too thick to get!

---
Ah, but that wasn't the point.

Since you wrote:

"If you mean PIR motion detectors, they usually have twin element
pyrometers (thin film thermistor)"...

The point was that that clearly indicates you thought PIR elements
were thermistors, which they never were, aren't, and probably never
will be.

I could be wrong, of course, and if you can provide an example of a
thermistor being used as a PIR motion detector, I'll be happy to
concede the point.
---

and not knowing that a Fresnel lens isn't just for use with IR

This is a copy/paste of what I typed: " Freznel type lenses (special IR
transparent material) "

Being "Freznel type lenses" they're obviously based on something that
existed before PIR sensors. - the more you wriggle - the more you have to be
disingenuous about what I actually said.

---
Disingenuousness has nothing to do with it, since it's all about
getting to the unvarnished truth and pointing out your errors.

For example, you wrote:

"Freznel type lenses (special IR transparent material)"...

which, if you're at all familiar with the English language, implies
that _Fresnel_ lenses are made from IR transparent material.

They're not, of course, in every case, and now that you've had ample
time to do your homework you come back pretending to have known then
what you've only found out now.
---

You're even too thick to snip what I actually said, so everyone can see
you're making it up the things I never said!

---
More wine, m'sieur?

--
JF

 

[Ian Field]

"John Fields" <jfields@austininstruments.com> wrote in message
news:dkbdh8tjts7qig750bf3oaunusuur5t47k@4ax.com...

On Sat, 9 Feb 2013 14:49:03 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
newsoubh85q6ulf4chg9smt9qo9dk1iluk09s@4ax.com...
On Fri, 8 Feb 2013 22:16:55 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
newsptah8t3j72uqpv442dj09supt25l4npcc@4ax.com...
On Thu, 7 Feb 2013 22:05:17 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:9d58h81gtrnkd2dm9ii3pi1cfn3h51ul04@4ax.com...
On Thu, 7 Feb 2013 20:54:23 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"John Fields" <jfields@austininstruments.com> wrote in message
news:2f55h8hgb34k7dk6bki11g1kee742avbuj@4ax.com...
On Wed, 6 Feb 2013 16:42:04 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:



"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote
in
message
news:j_gQs.69570$H5.27293@newsfe28.iad...
Ian Field wrote:



"Tim Williams" <tmoranwms@charter.net> wrote in message
news:keku69$6s1$1@dont-email.me...

AFAIK, pyroelectric sensors are a "single pixel" sort of
thing,
so
they
don't know if the scene is moving, only if the average IR
changes.
Which it does when someone comes into view or jumps out of the
shadows,


If you mean PIR motion detectors, they usually have twin
element
pyrometers (thin film thermistor) a motion of a IR source
(person)
is
"grated" to produce a gross change from one element to the
other -
this
is done in various ways such as Freznel type lenses (special IR
transparent material) and faceted surface reflecting
reflectors.

That's strange that you would call them thermistors? TO me a
thermistor
is a slow reacting device?

I have some continuity/voltage checkers with a thin film PTC in
series
with
an inverse parallel pair of high efficiency LEDs (2mA rating) -
the
series
PTC thermistor can react fast enough to protect the LEDs from
application
to
voltages upto 450V.

---
Apples and oranges.

Your usual disingenuous self!

My point is that a thin film thermistor can have a very fast
response
time -
there was no need to be specific exactly what material the thin film
was.

---
Identifying the materials was necessary in order to show you that
PTC's can't be PIR sensors, and vice versa.

Whether a thin-film PTC thermistor can have a very fast response
time
is irrelevant when the discussion is about PIR sensors so, as usual,
you're befuddled.

On the one hand, consider the PTC thermistor you described and, on
the
other, a PIR sensor.

The PTC thermistor is designed to have its resistance increase
spectacularly as it self-heats because of small changes in the
current
through it, while the PIR sensor is designed to generate a miniscule
charge when the temperatures its elements are exposed to change
abruptly, ergo apples and oranges.


Wriggle wriggle!

---
In which way?

Any which way it takes when caught out.

---
I merely point out your errors, and since you were caught out as not
knowing the difference between a thin-film thermistor and a PIR sensor

They can both be thin film - a point you're too thick to get!

---
Ah, but that wasn't the point.

Since you wrote:

"If you mean PIR motion detectors, they usually have twin element
pyrometers (thin film thermistor)"...

The point was that that clearly indicates you thought PIR elements
were thermistors, which they never were, aren't, and probably never
will be.

I could be wrong, of course, and if you can provide an example of a
thermistor being used as a PIR motion detector, I'll be happy to
concede the point.
---

and not knowing that a Fresnel lens isn't just for use with IR

This is a copy/paste of what I typed: " Freznel type lenses (special IR
transparent material) "

Being "Freznel type lenses" they're obviously based on something that
existed before PIR sensors. - the more you wriggle - the more you have to
be
disingenuous about what I actually said.

---
Disingenuousness has nothing to do with it, since it's all about
getting to the unvarnished truth and pointing out your errors.

For example, you wrote:

"Freznel type lenses (special IR transparent material)"...

which, if you're at all familiar with the English language, implies
that _Fresnel_ lenses are made from IR transparent material.

They're not, of course, in every case, and now that you've had ample
time to do your homework you come back pretending to have known then
what you've only found out now.

One of the PIR sensor datasheets I read described them as such, It was many
years ago that I worked for the alarm company that made the PIR alarms, I
can't remember the part number and I've no idea if I still have those old
datasheets.

But at least I've had actual hands on industrial experience - and not just
swinging through the trees beating my chest.

 

[Bret Cahill]

 We eventually found the breaker at the other side of the store & had
 to replace with a derated one because the resistance of the circuit
was too high.

Ron

Your wiring needs replacing, a short-circuit should blow even a breaker
of double that spec.

If you read the above text, we had to derate the circuit from 32A to 16 Amp
as the resistance of the circuit was too great for anything above a 16A
breaker to trip in the required time. Wiring otherwise tested OK.> Or you can wait until the house burns down.....

That's the point, CB was FAULTY & not testable.

It seems like it was "over fused" or "over breakered" but how do you
know it was faulty if there was no test to determine if it was faulty?

Apparently you had _some_ test to determine if it was faulty.


Bret Cahill