Help me solve this design problem PLEEEZ

[petrus bitbyter]

Even if you leave that out, the sneaky b*ggers have opposable thumbs
and enough intelligence (or perhaps some kind of instinct) to operate
the plug on the power cord.


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

You can try to overcome this security hole by taking a 5 minutes delay
immediately after power up. Nevertheless, it's like copy protection. One day
someone will find a way to circumvent this delay or what measure you ever
take to prevent the equipment being used over 50% duty cycle. But then it
sure will be done deliberately, not accidentaly.

petrus bitbyter

 

[Tony Williams]

Perhaps you could use an NTC on a nice heatsink,
instead of a cap. Puts the environmental temperature
into the emulation... A piece of aluminium with plenty
holes in it, and a large bag of nuts and bolts, to
calibrate the heatsink

Brass, M6, of course.

 

[funster]

Even if you leave that out, the sneaky b*ggers have opposable thumbs
and enough intelligence (or perhaps some kind of instinct) to operate
the plug on the power cord.

Well, you're definitely right on this one... These crane operators are
known to stick their hands into a 250 VDC panel from time to time.
This magnet is on a bridging crane (one in which the operator goes for
the ride). One time a maintenance employee looked up at the crane
overhead and saw the operator in front of an open electrical panel.
Soon later the maintenance dept. got a call that the crane was
inoperable. Apparently the operator wanted to set himself up with a
comfortable long break while the repair had to be done. Management put
an end to this by requiring the operator to sit in his crane cab
whether or not the crane was operable.

So, any design would have to consider attempts to defeat the system.
If the operator could just reset the clock by turning on and off the
power, that wouldn't be an acceptable design.


BTW, if anyone has a need for "vandal resistant screws" they are
available through McMaster Carr. I've seen many instances in a factory
where they are useful. Employees at the shop love to turn down the
volume on the speakers for the public address system. Then they can't
hear when they are called for a job. When the boss walks over to talk
to the worker in person, he just says, "What? I couldn't hear you
because the speaker is "not working". Vandal resistant screws would
make it difficult for personel to open the local call-boxes and
manually turn down the volume control.

Best regards,
Spehro Pefhany

http://www.speff.com

 

[Clarence_A]

Well, you're definitely right on this one... These crane operators are
known to stick their hands into a 250 VDC panel from time to time.
This magnet is on a bridging crane (one in which the operator goes for
the ride). One time a maintenance employee looked up at the crane
overhead and saw the operator in front of an open electrical panel.
Soon later the maintenance dept. got a call that the crane was
inoperable. Apparently the operator wanted to set himself up with a
comfortable long break while the repair had to be done. Management put
an end to this by requiring the operator to sit in his crane cab
whether or not the crane was operable.

So, any design would have to consider attempts to defeat the system.
If the operator could just reset the clock by turning on and off the
power, that wouldn't be an acceptable design.


BTW, if anyone has a need for "vandal resistant screws" they are
available through McMaster Carr. I've seen many instances in a factory
where they are useful. Employees at the shop love to turn down the
volume on the speakers for the public address system. Then they can't
hear when they are called for a job. When the boss walks over to talk
to the worker in person, he just says, "What? I couldn't hear you
because the speaker is "not working". Vandal resistant screws would
make it difficult for personnel to open the local call-boxes and
manually turn down the volume control.

Are you suggesting these dolts are too stupid to buy a matching
screwdriver? They sell a "security" kit of screwdriver bits for
about $5 in the local tool shop.

 

[funster]

I am amazed at how quickly people hurl insults at one-another on the
internet. I've heard that when there is a conference of one type or
another and these flamers actually see one-another face-to-face, they
act very politely to one another. None of this "%&@#$ off you $@^*#("
LOL.

Here's my theory: People in real life are used to being treated in
accordance with the position they have or haven't achieved. Thus, a
superintendant in charge of a department is used to people listening to
him when he speaks. A high-school dropout construction worker employed
by an abusive Italian foreman is used to being cursed at on a daily
basis. On the internet, everyone is apparently equal and so the
high-school dropout is equally free to cuss out the department chief.
So, let's just try to have fun here.

 

[funster]

For this application, that probably wouldn't work. When the operator
hops in the crane he (and the company) want it to work right-away.

 

[funster]

Wow man, thanks. I'm going to build this one just as a way of
educating myself. However, the circuit for the actual application
would have to have a clock readout. I looked a little bit into a RC
charging circuit, but that is non-linear. Does anyone out there know
of a simple linear ramp circuit? Let's say I needed 0 to 5 VDC and I
needed it to take 300 seconds to get there. Is there a simple circuit
out there which ramps up in a non-exponential, linear fashion? So far,
the 4060 chip linked to the decade counter looks good and cheap. I
could build a working device for low cost and present it to
supervision. This would be the "Chevy" version of the circuit. Later
on, after sufficiently educated in the ways of PIC microcontrollers I
could probably make an attempt at the more sophisticated version with
the serial output... The "Cadillac" of all electromagnet monitoring
circuits!

 

[Spehro Pefhany]

Are you suggesting these dolts are too stupid to buy a matching
screwdriver? They sell a "security" kit of screwdriver bits for
about $5 in the local tool shop.

Amazing isn't it? You can either pay a fortune for a genuine tool, or
a few bucks for a knock-off set from China or Taiwan that work well
enough on most of them. My old car radio was held in with a bizarre
5-sided "hex key" ("pent key"?) that I machined up rather than pay the
SOBs for the matching tool.


Best regards,
Spehro Pefhany

 

[John Woodgate]

On the internet, everyone is apparently equal and so the high-school
dropout is equally free to cuss out the department chief. So, let's
just try to have fun here.

It's a bit more than that. Because most of us haven't met, there is a
bit of evolutionary-protective xenophobia. This usually only operates
when some small trigger phrase or inference occurs. OTOH, some are stuck
in a pathologically xenophobic mode and see a need to flame every
newcomer. This is justified only about half of the time. (;-)

 

[John Woodgate]

Vandal resistant screws would make it difficult for personel to open
the local call-boxes and manually turn down the volume control.

Bit sets for all the known types are freely available from broad-line
distributors and I think I saw a set in Sears-Roebuck when I was in USA
last. Everyone should have one. (;-)

In UK, the ISCE doesn't advise user-accessible volume controls at all.
But people hang blankets over the loudspeakers or poke holes in the
cones.

 

[John Fields]

Wow man, thanks. I'm going to build this one just as a way of
educating myself. However, the circuit for the actual application
would have to have a clock readout. I looked a little bit into a RC
charging circuit, but that is non-linear. Does anyone out there know
of a simple linear ramp circuit? Let's say I needed 0 to 5 VDC and I
needed it to take 300 seconds to get there. Is there a simple circuit
out there which ramps up in a non-exponential, linear fashion? So far,
the 4060 chip linked to the decade counter looks good and cheap. I
could build a working device for low cost and present it to
supervision. This would be the "Chevy" version of the circuit. Later
on, after sufficiently educated in the ways of PIC microcontrollers I
could probably make an attempt at the more sophisticated version with
the serial output... The "Cadillac" of all electromagnet monitoring
circuits!

 

[Robert Monsen]

Wow man, thanks. I'm going to build this one just as a way of
educating myself. However, the circuit for the actual application
would have to have a clock readout. I looked a little bit into a RC
charging circuit, but that is non-linear. Does anyone out there know
of a simple linear ramp circuit? Let's say I needed 0 to 5 VDC and I
needed it to take 300 seconds to get there. Is there a simple circuit
out there which ramps up in a non-exponential, linear fashion? So far,
the 4060 chip linked to the decade counter looks good and cheap. I
could build a working device for low cost and present it to
supervision. This would be the "Chevy" version of the circuit. Later
on, after sufficiently educated in the ways of PIC microcontrollers I
could probably make an attempt at the more sophisticated version with
the serial output... The "Cadillac" of all electromagnet monitoring
circuits!

Tony's circuit does this. It uses a constant current source.

Since I = C * dV/dt, if you keep the current constant, the change in
voltage with time will be linear, ie, a ramp.

You could use one of those voltmeter LCD thingys to display the time
left by doing a little interfacing. Getting it to display in seconds
might be a challenge. An analog voltage meter would move the needle
around, so perhaps you could change the reference card to display time
rather than voltage?

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Clarence_A]

I read in sci.electronics.design that funster

(in <[email protected]>) about 'Help
me solve this design problem PLEEEZ', on Mon, 4 Apr 2005:

Bit sets for all the known types are freely available from broad-line
distributors and I think I saw a set in Sears-Roebuck when I was in USA
last. Everyone should have one. (;-)

In UK, the ISCE doesn't advise user-accessible volume controls at all.
But people hang blankets over the loudspeakers or poke holes in

the > cones.

I like three layers of bubble wrap held in place with Duct tape.

 

[Terry Given]

about 'Help


in USA


at all.


the > cones.

I like three layers of bubble wrap held in place with Duct tape.

Just ignoring it works too. Oddly enough, many of the high-tech
companies I have worked for have had appalling, unintelligible PA
systems. Weird - why cant a company that manufactures picoJoule laser
pulse detectors get a PA to work?

Cheers
Terry

 

[Jim Thompson]

[snip]

Just ignoring it works too. Oddly enough, many of the high-tech
companies I have worked for have had appalling, unintelligible PA
systems. Weird - why cant a company that manufactures picoJoule laser
pulse detectors get a PA to work?

Cheers
Terry

My vote for the worst is the drive-up intercoms at fast-food places.

Reminds me of a funny.....

Bob Widlar just hated the paging speakers spread throughout the
National facility in Santa Clara.

His complaints were ignored.

So, one day, he showed up to work with a "plumber's helper" and some
cherry bombs.

Place cherry bomb in "plumber's helper" cup, light fuse, then raise
arm up and hold cup against ceiling speaker... instant relief ;-)

...Jim Thompson

 

[Terry Given]

[snip]

Just ignoring it works too. Oddly enough, many of the high-tech
companies I have worked for have had appalling, unintelligible PA
systems. Weird - why cant a company that manufactures picoJoule laser
pulse detectors get a PA to work?

Cheers
Terry

My vote for the worst is the drive-up intercoms at fast-food places.

Reminds me of a funny.....

Bob Widlar just hated the paging speakers spread throughout the
National facility in Santa Clara.

His complaints were ignored.

So, one day, he showed up to work with a "plumber's helper" and some
cherry bombs.

Place cherry bomb in "plumber's helper" cup, light fuse, then raise
arm up and hold cup against ceiling speaker... instant relief ;-)

...Jim Thompson

LOL.

Did you know Bob Widlar?

And when are you going to write a book?

Cheers
Terry

 

[John Woodgate]

I like three layers of bubble wrap held in place with Duct tape.

Very possibly, but how do you reduce the sound output of a loudspeaker?

 

[John Woodgate]

I read in sci.electronics.design that Terry Given <[email protected]>

Just ignoring it works too. Oddly enough, many of the high-tech
companies I have worked for have had appalling, unintelligible PA
systems. Weird - why cant a company that manufactures picoJoule laser
pulse detectors get a PA to work?

Because people who are not into audio think it's easy. It's not
(usually) highly sophisticated but it isn't simple.

 

[Robert Monsen]

Tony's circuit does this. It uses a constant current source.

Correction. Tony graciously pointed out to me in private email that his
circuit is actually doing an exponential decay, due to the resistor
parallel to the timing cap. Thus, my prior message is based on an
incorrect understanding of the circuit, and should be disregarded.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Jim Thompson]

[snip]

Just ignoring it works too. Oddly enough, many of the high-tech
companies I have worked for have had appalling, unintelligible PA
systems. Weird - why cant a company that manufactures picoJoule laser
pulse detectors get a PA to work?

Cheers
Terry

My vote for the worst is the drive-up intercoms at fast-food places.

Reminds me of a funny.....

Bob Widlar just hated the paging speakers spread throughout the
National facility in Santa Clara.

His complaints were ignored.

So, one day, he showed up to work with a "plumber's helper" and some
cherry bombs.

Place cherry bomb in "plumber's helper" cup, light fuse, then raise
arm up and hold cup against ceiling speaker... instant relief ;-)

...Jim Thompson

LOL.

Did you know Bob Widlar?

Yes, but on a more professional level than as friend... I never did go
drinking with him ;-)

I worked a Philco-Ford Semiconductor in 1968, right next door to
National. When Philco-Ford shut that facility I got my technician,
Jim Foster, a job working for Widlar. Another former technician of
mine, Jim Estep, also worked for Widlar, but via a separate hiring
path. (At one point in time there were 5 "Jim's" in my group... see
why I broke family tradition and named none of my sons James ... ?

Widlar always seemed to mistrust me. I'd often show up over there to
take Jim F to lunch, and Widlar would stand in his lab door so I
couldn't go in ;-)

One of my associates was stopped, along with Bob, traveling in
separate cars, for DUI. The cop let them go after it was determined
that the cop's brother worked for Bob.

And when are you going to write a book?

Cheers
Terry

I debate about that. I don't know what to write about. My expertise
is in ASIC's... does anyone care?

...Jim Thompson