need help with a senior project for college

[Jim Bancroft]

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board
to the design that generates an AM or FM signal to a remote device
that lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use
the output to be the power that activates a switch that turns on an
LED?

Most of you guys are way beyond me technically, so, please be
gentle!

I already have a circuit for the roulette wheel, I am copying a
previous advanced digital circuit we did in class, but I wanted to use
some of the outputs to send an RF signal and need help with finding
similar frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band
and others are commercial band, most FM transmitters are commercial
band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

 

[Tim Wescott]

On Tue, 02 Feb 2010 17:55:29 -0800, Jim Bancroft wrote:

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board to
the design that generates an AM or FM signal to a remote device that
lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use the
output to be the power that activates a switch that turns on an LED?

Most of you guys are way beyond me technically, so, please be gentle!

I already have a circuit for the roulette wheel, I am copying a previous
advanced digital circuit we did in class, but I wanted to use some of
the outputs to send an RF signal and need help with finding similar
frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band and
others are commercial band, most FM transmitters are commercial band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

Now that's putting the "senior" in "senior project" (sorry, I couldn't
resist. I was born in '62 -- you're young).

There are transmit/receive module pairs out there that you can get, that
are easy to interface to. I have no idea what your budget is, but that'd
be the easy way to go.

--
www.wescottdesign.com

 

[Hammy]

On Tue, 02 Feb 2010 17:55:29 -0800, Jim Bancroft wrote:

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board to
the design that generates an AM or FM signal to a remote device that
lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use the
output to be the power that activates a switch that turns on an LED?

Most of you guys are way beyond me technically, so, please be gentle!

I already have a circuit for the roulette wheel, I am copying a previous
advanced digital circuit we did in class, but I wanted to use some of
the outputs to send an RF signal and need help with finding similar
frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band and
others are commercial band, most FM transmitters are commercial band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

Yes I agree with Tim it would be much simpler to use prebuilt and

tested RF modules here is a good selection.

http://www.rentron.com/PicBasic/RemoteControl.htm

http://www.linxtechnologies.com/Products/RF-Modules/

Google also "Micrel's QwikRadio"

Or if it's line of site you could use IR (infrared) cheaper and easier
and no problems with FCC etc.

 

[Michael A. Terrell]

Tim Wescott wrote:

Now that's putting the "senior" in "senior project" (sorry, I couldn't
resist. I was born in '62 -- you're young).

So are you. I was born in 52.


--
Greed is the root of all eBay.

 

[Jim Bancroft]

On Feb 3, 7:49 am, Hammy <s...@spam.com> wrote:

On Tue, 02 Feb 2010 17:55:29 -0800, Jim Bancroft wrote:

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board to
the design that generates an AM or FM signal to a remote device that
lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use the
output to be the power that activates a switch that turns on an LED?

Most of you guys are way beyond me technically, so, please be gentle!

I already have a circuit for the roulette wheel, I am copying a previous
advanced digital circuit we did in class, but I wanted to use some of
the outputs to send an RF signal and need help with finding similar
frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band and
others are commercial band, most FM transmitters are commercial band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

Yes I agree with Tim it would be much simpler to use prebuilt and
tested RF modules here is a good selection.

http://www.rentron.com/PicBasic/RemoteControl.htm

http://www.linxtechnologies.com/Products/RF-Modules/

Google also "Micrel's QwikRadio"

Or if it's line of site you could use IR (infrared) cheaper and easier
and no problems with FCC etc.- Hide quoted text -

- Show quoted text -

You and Tim are the best!
It's a place to start!

However, I need to make sure they have schematics, I need to ORCAD the
thing out and make my own board

 

On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
<ctgatheringofeagles@gmail.com> wrote:

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board
to the design that generates an AM or FM signal to a remote device
that lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use
the output to be the power that activates a switch that turns on an
LED?

Most of you guys are way beyond me technically, so, please be
gentle!

I already have a circuit for the roulette wheel, I am copying a
previous advanced digital circuit we did in class, but I wanted to use
some of the outputs to send an RF signal and need help with finding
similar frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band
and others are commercial band, most FM transmitters are commercial
band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

Depending on where you are in the world, there are relatively
inexpensive transmitters and receivers on 315mHz (US) or 433mHz (rest
of the world).

315mHz transmitters and receivers are available on Ebay for $3US each,
plus shipping. They have a range of more than 50 feet (haven't tried
further).

transmitter:
http://cgi.ebay.com/PCF10-FS1000A-315-MHz-Wireless-Radio-Transmitter_W0QQitemZ290316935644QQcmdZViewItemQQptZRadio_Control_Vehicles?hash=item43983ce1dc

receiver:
http://cgi.ebay.com/PCR1A-315-MHz-Wireless-Radio-Superregeneration-Receiver_W0QQitemZ290332568114QQcmdZViewItemQQptZRadio_Control_Vehicles?hash=item43992b6a32


If you're not in the US, search for
433 transmitter
and
433 receiver

John

 

[pimpom]

Michael A. Terrell wrote:

Tim Wescott wrote:

Now that's putting the "senior" in "senior project" (sorry, I
couldn't resist. I was born in '62 -- you're young).

So are you. I was born in 52.

And *I* can claim a one-year seniority over *you*
When I first came to the sci.electronics groups years ago, I
expected most posters to be much younger than me. But it
gradually became evident that such was not the case.

I also often take part in a computer forum hosted by an Indian
publishing company. I enjoy interacting with people young enough
to be my children and grandchildren with the exuberance and brash
confidence of youth. But there are times when it gets a bit too
much and I stay away for a few months. On returning, I usually
find a few posts and private messages asking where I'd gone.

One thread starter's post that brings up a smile every time I
think about it asked, in all sincerity, up to what age a person
keeps growing wiser. The OP and some others thought that a man
reaches the peak of wisdom in his early twenties.

To the OP: I aso think adapting an existing module would be your
best option.

 

[Paul E. Schoen]

"Jim Bancroft" <ctgatheringofeagles@gmail.com> wrote in message
news:a6663b8e-b854-430a-95ad-393e3ad48ce1@a13g2000vbf.googlegroups.com...
On Feb 3, 7:49 am, Hammy <s...@spam.com> wrote:

On Tue, 02 Feb 2010 17:55:29 -0800, Jim Bancroft wrote:

I am a 50 year old fart who got hurt at work and qualified for
vocational rehab and am getting my second AS degree, this time in EE.

For my project, I want to modify my 85 year old Mom's tea kettel, so
when the steam blows, it spins a dc motor to provide current to a
roulette wheel circuit to llight LED's, the LED's stopping as a cap
discharges.

However, since she is stone deaf almost, I also wanted to add a board
to
the design that generates an AM or FM signal to a remote device that
lights up an LED next to her chair

Any help on designs for AM/FM transmitters/receivers that I can use
the
output to be the power that activates a switch that turns on an LED?

Most of you guys are way beyond me technically, so, please be gentle!


I already have a circuit for the roulette wheel, I am copying a
previous
advanced digital circuit we did in class, but I wanted to use some of
the outputs to send an RF signal and need help with finding similar
frequency range transmitters and receivers.

I found several versions of fm and am transmitters and receivers but
none of the frequencies match, some of the transmitters are HF band
and
others are commercial band, most FM transmitters are commercial band

I just need something simple I can use and if you can tell me the part
numbers with it, please??

Yes I agree with Tim it would be much simpler to use prebuilt and
tested RF modules here is a good selection.

http://www.rentron.com/PicBasic/RemoteControl.htm

http://www.linxtechnologies.com/Products/RF-Modules/

Google also "Micrel's QwikRadio"

Or if it's line of site you could use IR (infrared) cheaper and easier
and no problems with FCC etc.- Hide quoted text -

- Show quoted text -

You and Tim are the best!
It's a place to start!

However, I need to make sure they have schematics, I need to ORCAD the
thing out and make my own board

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

Try http://www.microchip.com/ and search for rfPic. They have an
inexpensive development kit. I bought one at one of their Masters
conferences a few years back but never used it. They also have wireless
solutions using ZigBee, IR and WiFi. Their app note AN242 has schematics
and even board layout and BOM and antenna design. It uses 433 MHz with ASK
modulation, and is FCC approved.

Here's an article:
http://www.circellar.com/library/print/1202/Eady149/3.htm

They also have an excellent technical forum where you can get help from
other Microchippers and PICkers. Here's their Zigbee and Wireless forum:
http://www.microchip.com/forums/tt.aspx?forumid=177

rfPic:
http://www.microchip.com/forums/tt.aspx?forumid=166&tmode=1&smode=1&p=1

Good luck, young whippersnapper... I'm 60

Paul

 

[Hammy]

On Tue, 02 Feb 2010 17:55:29 -0800, Jim Bancroft wrote:


However, I need to make sure they have schematics, I need to ORCAD the
thing out and make my own board

IF you follow the Rentron link I gave you they have demo schematics
typical applications.

You can find a typical application schematic in pdf as well as other
relevant stuff here like supporting components etc.

Bottom of the page.

TWS-434A RF Transmitter Module

http://www.rentron.com/remote_control/TWS-434.htm

Same applies for the

RWS-434 RF Receiver Module

http://www.rentron.com/remote_control/RWS-434.htm

If you browse the site they should have a project using both modules.
Ah here's one project using them.

http://www.rentron.com/RF-Remote.htm

 

[Ross Herbert]

On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
<ctgatheringofeagles@gmail.com> wrote:

:I am a 50 year old fart who got hurt at work and qualified for
:vocational rehab and am getting my second AS degree, this time in EE.
:
:For my project, I want to modify my 85 year old Mom's tea kettel, so
:when the steam blows, it spins a dc motor to provide current to a
:roulette wheel circuit to llight LED's, the LED's stopping as a cap
:discharges.
:
:However, since she is stone deaf almost, I also wanted to add a board
:to the design that generates an AM or FM signal to a remote device
:that lights up an LED next to her chair
:
:Any help on designs for AM/FM transmitters/receivers that I can use
:the output to be the power that activates a switch that turns on an
:LED?
:
:Most of you guys are way beyond me technically, so, please be
:gentle!
:
:I already have a circuit for the roulette wheel, I am copying a
revious advanced digital circuit we did in class, but I wanted to use
:some of the outputs to send an RF signal and need help with finding
:similar frequency range transmitters and receivers.
:
:I found several versions of fm and am transmitters and receivers but
:none of the frequencies match, some of the transmitters are HF band
:and others are commercial band, most FM transmitters are commercial
:band
:
:I just need something simple I can use and if you can tell me the part
:numbers with it, please??


Before you get to the remote sounder part of the design (that's relatively
simple with the transceiver modules mentioned) you should spend some time on
thinking through a reliable boil detect system. Your idea of using the steam
pressure to spin a fan motor is cumbersome, and to my mind, impractical -
especially for an elderly person. I would abandon this idea and use a detector
which monitors the current through the kettle heater element. I envisage that
when the kettle is switched on the heater current passes through a single turn
primary (heavy gauge wire) on a small toroidal transformer which is then stepped
up by a suitable turns ratio to provide a voltage source suitable to trigger say
a 555 which then takes control of all other subsequent functions. I would mount
all the electronics in a box which has a normal mains cord and plug at the input
and a a mains output socket into which the kettle is plugged. The circuitry
could be configured to flash the LED and sound the remote alarm for a suitable
time period before resetting ready for the next operation.

 

[Michael Black]

On Fri, 5 Feb 2010, Ross Herbert wrote:

On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
ctgatheringofeagles@gmail.com> wrote:

:I am a 50 year old fart who got hurt at work and qualified for
:vocational rehab and am getting my second AS degree, this time in EE.
:
:For my project, I want to modify my 85 year old Mom's tea kettel, so
:when the steam blows, it spins a dc motor to provide current to a
:roulette wheel circuit to llight LED's, the LED's stopping as a cap
:discharges.
:
:However, since she is stone deaf almost, I also wanted to add a board
:to the design that generates an AM or FM signal to a remote device
:that lights up an LED next to her chair
:
:Any help on designs for AM/FM transmitters/receivers that I can use
:the output to be the power that activates a switch that turns on an
:LED?
:
:Most of you guys are way beyond me technically, so, please be
:gentle!
:
:I already have a circuit for the roulette wheel, I am copying a
revious advanced digital circuit we did in class, but I wanted to use
:some of the outputs to send an RF signal and need help with finding
:similar frequency range transmitters and receivers.
:
:I found several versions of fm and am transmitters and receivers but
:none of the frequencies match, some of the transmitters are HF band
:and others are commercial band, most FM transmitters are commercial
:band
:
:I just need something simple I can use and if you can tell me the part
:numbers with it, please??


Before you get to the remote sounder part of the design (that's relatively
simple with the transceiver modules mentioned) you should spend some time on
thinking through a reliable boil detect system. Your idea of using the steam
pressure to spin a fan motor is cumbersome, and to my mind, impractical -
especially for an elderly person. I would abandon this idea and use a detector
which monitors the current through the kettle heater element. I envisage that
when the kettle is switched on the heater current passes through a single turn
primary (heavy gauge wire) on a small toroidal transformer which is then stepped
up by a suitable turns ratio to provide a voltage source suitable to trigger say
a 555 which then takes control of all other subsequent functions. I would mount
all the electronics in a box which has a normal mains cord and plug at the input
and a a mains output socket into which the kettle is plugged. The circuitry
could be configured to flash the LED and sound the remote alarm for a suitable
time period before resetting ready for the next operation.

I envisioned a non-electric kettle. But I also remember there used to be

bits on the old kettles that would whistle when the kettle was boiling,
which then would allow for something to be triggered by the whistle.

I didn't really think the project was well thought through, though I
wasn't sure whether the point of the project was to be innovative, or
to learn and display practical skills like soldering and such. If it's
the former, then I'm not sure enough time has been spent on the sensor,
and the wireless link is just gloss that would often be handled by
commercial modules in some other setting. If it's about practical skills
then I guess it matters more to show off how to solder and build an actual
working project.

Michael

 

[Paul E. Schoen]

"Ross Herbert" <rherber1@bigpond.net.au> wrote in message
news:9gvmm515vdgq61ahgcvm9rlishedmpc8d8@4ax.com...

On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
ctgatheringofeagles@gmail.com> wrote:

:I am a 50 year old fart who got hurt at work and qualified for
:vocational rehab and am getting my second AS degree, this time in EE.
:
:For my project, I want to modify my 85 year old Mom's tea kettel, so
:when the steam blows, it spins a dc motor to provide current to a
:roulette wheel circuit to llight LED's, the LED's stopping as a cap
:discharges.
:
:However, since she is stone deaf almost, I also wanted to add a board
:to the design that generates an AM or FM signal to a remote device
:that lights up an LED next to her chair
:
:Any help on designs for AM/FM transmitters/receivers that I can use
:the output to be the power that activates a switch that turns on an
:LED?
:
:Most of you guys are way beyond me technically, so, please be
:gentle!
:
:I already have a circuit for the roulette wheel, I am copying a
revious advanced digital circuit we did in class, but I wanted to use
:some of the outputs to send an RF signal and need help with finding
:similar frequency range transmitters and receivers.
:
:I found several versions of fm and am transmitters and receivers but
:none of the frequencies match, some of the transmitters are HF band
:and others are commercial band, most FM transmitters are commercial
:band
:
:I just need something simple I can use and if you can tell me the part
:numbers with it, please??


Before you get to the remote sounder part of the design (that's
relatively
simple with the transceiver modules mentioned) you should spend some time
on
thinking through a reliable boil detect system. Your idea of using the
steam
pressure to spin a fan motor is cumbersome, and to my mind, impractical -
especially for an elderly person. I would abandon this idea and use a
detector
which monitors the current through the kettle heater element. I envisage
that
when the kettle is switched on the heater current passes through a single
turn
primary (heavy gauge wire) on a small toroidal transformer which is then
stepped
up by a suitable turns ratio to provide a voltage source suitable to
trigger say
a 555 which then takes control of all other subsequent functions. I would
mount
all the electronics in a box which has a normal mains cord and plug at
the input
and a a mains output socket into which the kettle is plugged. The
circuitry
could be configured to flash the LED and sound the remote alarm for a
suitable
time period before resetting ready for the next operation.

What might be even more practical and also a good safety product in
general, would be a combination of a timer as well as a "dry pot" detector
for electric stoves and other appliances. I have considered adding this to
my hot plate after I have several times forgotten about a pot of water and
luckily smelled the hot metal or Teflon lining after it had gone dry, but
before it melted or disintegrated onto the floor or counter.

Usually one can guess how long it will take to heat a pot containing a
certain amount of water, and the timer can be set to about that long. But
it should also be possible to determine when the pot has gone dry, because
as long as there is water in it, the temperature should not be much above
100C. But as soon as the water evaporates, all the nergy of a 1000 watt or
more element will go into heating a rather thin piece of metal and it will
soon reach several hundred degrees. An alarm would be good, but even better
would be a relay to turn off the supply to the element.

Hey, I might even *buy* something like that! I can make it myself, but I
know I never will.

Paul

 

[Fred Abse]

On Wed, 03 Feb 2010 08:28:05 -0500, Michael A. Terrell wrote:

Tim Wescott wrote:

Now that's putting the "senior" in "senior project" (sorry, I couldn't
resist. I was born in '62 -- you're young).

So are you. I was born in 52.

Children

I was born in 43

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)

 

[Ross Herbert]

On Thu, 4 Feb 2010 21:43:30 -0500, Michael Black <et472@ncf.ca> wrote:

:On Fri, 5 Feb 2010, Ross Herbert wrote:
:
:> On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
:> <ctgatheringofeagles@gmail.com> wrote:
:>
:> :I am a 50 year old fart who got hurt at work and qualified for
:> :vocational rehab and am getting my second AS degree, this time in EE.
:> :
:> :For my project, I want to modify my 85 year old Mom's tea kettel, so
:> :when the steam blows, it spins a dc motor to provide current to a
:> :roulette wheel circuit to llight LED's, the LED's stopping as a cap
:> :discharges.
:> :
:> :However, since she is stone deaf almost, I also wanted to add a board
:> :to the design that generates an AM or FM signal to a remote device
:> :that lights up an LED next to her chair
:> :
:> :Any help on designs for AM/FM transmitters/receivers that I can use
:> :the output to be the power that activates a switch that turns on an
:> :LED?
:> :
:> :Most of you guys are way beyond me technically, so, please be
:> :gentle!
:> :
:> :I already have a circuit for the roulette wheel, I am copying a
:> revious advanced digital circuit we did in class, but I wanted to use
:> :some of the outputs to send an RF signal and need help with finding
:> :similar frequency range transmitters and receivers.
:> :
:> :I found several versions of fm and am transmitters and receivers but
:> :none of the frequencies match, some of the transmitters are HF band
:> :and others are commercial band, most FM transmitters are commercial
:> :band
:> :
:> :I just need something simple I can use and if you can tell me the part
:> :numbers with it, please??
:>
:>
:> Before you get to the remote sounder part of the design (that's relatively
:> simple with the transceiver modules mentioned) you should spend some time on
:> thinking through a reliable boil detect system. Your idea of using the steam
:> pressure to spin a fan motor is cumbersome, and to my mind, impractical -
:> especially for an elderly person. I would abandon this idea and use a
detector
:> which monitors the current through the kettle heater element. I envisage that
:> when the kettle is switched on the heater current passes through a single
turn
:> primary (heavy gauge wire) on a small toroidal transformer which is then
stepped
:> up by a suitable turns ratio to provide a voltage source suitable to trigger
say
:> a 555 which then takes control of all other subsequent functions. I would
mount
:> all the electronics in a box which has a normal mains cord and plug at the
input
:> and a a mains output socket into which the kettle is plugged. The circuitry
:> could be configured to flash the LED and sound the remote alarm for a
suitable
:> time period before resetting ready for the next operation.
:>
:I envisioned a non-electric kettle. But I also remember there used to be
:bits on the old kettles that would whistle when the kettle was boiling,
:which then would allow for something to be triggered by the whistle.

You may be correct. I haven't used a hotplate heated kettle for so long I failed
to consider that the OP's mum might not be using an electric kettle.

:
:I didn't really think the project was well thought through, though I
:wasn't sure whether the point of the project was to be innovative, or
:to learn and display practical skills like soldering and such. If it's
:the former, then I'm not sure enough time has been spent on the sensor,
:and the wireless link is just gloss that would often be handled by
:commercial modules in some other setting. If it's about practical skills
:then I guess it matters more to show off how to solder and build an actual
:working project.
:

Since the OP's elderly mum has to use the thing, it also has to be simple to use
AND reliable. Even using a hotplate type kettle I can't see how these two
criteria could be met using a fan motor turned by the steam emanating from the
spout of the kettle as a temperature sensor.

If the OP does in fact mean to apply his idea to a non-electric kettle then it
would be far simpler to use a 1N4148 or similar diode mounted in a short section
of sealed diameter metal tubing inserted into the kettle spout as a temperature
sensor.

 

[Ross Herbert]

On Thu, 4 Feb 2010 21:45:32 -0500, "Paul E. Schoen" <paul@peschoen.com> wrote:

:
:"Ross Herbert" <rherber1@bigpond.net.au> wrote in message
:news:9gvmm515vdgq61ahgcvm9rlishedmpc8d8@4ax.com...
:> On Tue, 2 Feb 2010 17:55:29 -0800 (PST), Jim Bancroft
:> <ctgatheringofeagles@gmail.com> wrote:
:>
:> :I am a 50 year old fart who got hurt at work and qualified for
:> :vocational rehab and am getting my second AS degree, this time in EE.
:> :
:> :For my project, I want to modify my 85 year old Mom's tea kettel, so
:> :when the steam blows, it spins a dc motor to provide current to a
:> :roulette wheel circuit to llight LED's, the LED's stopping as a cap
:> :discharges.
:> :
:> :However, since she is stone deaf almost, I also wanted to add a board
:> :to the design that generates an AM or FM signal to a remote device
:> :that lights up an LED next to her chair
:> :
:> :Any help on designs for AM/FM transmitters/receivers that I can use
:> :the output to be the power that activates a switch that turns on an
:> :LED?
:> :
:> :Most of you guys are way beyond me technically, so, please be
:> :gentle!
:> :
:> :I already have a circuit for the roulette wheel, I am copying a
:> revious advanced digital circuit we did in class, but I wanted to use
:> :some of the outputs to send an RF signal and need help with finding
:> :similar frequency range transmitters and receivers.
:> :
:> :I found several versions of fm and am transmitters and receivers but
:> :none of the frequencies match, some of the transmitters are HF band
:> :and others are commercial band, most FM transmitters are commercial
:> :band
:> :
:> :I just need something simple I can use and if you can tell me the part
:> :numbers with it, please??
:>
:>
:> Before you get to the remote sounder part of the design (that's
:> relatively
:> simple with the transceiver modules mentioned) you should spend some time
:> on
:> thinking through a reliable boil detect system. Your idea of using the
:> steam
:> pressure to spin a fan motor is cumbersome, and to my mind, impractical -
:> especially for an elderly person. I would abandon this idea and use a
:> detector
:> which monitors the current through the kettle heater element. I envisage
:> that
:> when the kettle is switched on the heater current passes through a single
:> turn
:> primary (heavy gauge wire) on a small toroidal transformer which is then
:> stepped
:> up by a suitable turns ratio to provide a voltage source suitable to
:> trigger say
:> a 555 which then takes control of all other subsequent functions. I would
:> mount
:> all the electronics in a box which has a normal mains cord and plug at
:> the input
:> and a a mains output socket into which the kettle is plugged. The
:> circuitry
:> could be configured to flash the LED and sound the remote alarm for a
:> suitable
:> time period before resetting ready for the next operation.
:
:What might be even more practical and also a good safety product in
:general, would be a combination of a timer as well as a "dry pot" detector
:for electric stoves and other appliances. I have considered adding this to
:my hot plate after I have several times forgotten about a pot of water and
:luckily smelled the hot metal or Teflon lining after it had gone dry, but
:before it melted or disintegrated onto the floor or counter.
:
:Usually one can guess how long it will take to heat a pot containing a
:certain amount of water, and the timer can be set to about that long. But
:it should also be possible to determine when the pot has gone dry, because
:as long as there is water in it, the temperature should not be much above
:100C. But as soon as the water evaporates, all the nergy of a 1000 watt or
:more element will go into heating a rather thin piece of metal and it will
:soon reach several hundred degrees. An alarm would be good, but even better
:would be a relay to turn off the supply to the element.
:
:Hey, I might even *buy* something like that! I can make it myself, but I
:know I never will.
:
aul
:


The main problem with these sorts of safety devices is that they must be
manually mounted to the cooking utensil itself every time the user puts the
utensil on the hotplate. I don't think the majority of people would be bothered
to do this so it would be a waste of time designing it. However, where the user
is concientious enough to mount the sensor every time, it would be a good idea.

If a glass ceramic hotplate is used the boil dry sensor could be incorporated in
the hotplate so that it senses the increase in temperature of the ceramic when a
utensil boils dry and this would be the way to go. Similarly so for an induction
type hotplate.

 

[Michael A. Terrell]

Fred Abse wrote:

On Wed, 03 Feb 2010 08:28:05 -0500, Michael A. Terrell wrote:


Tim Wescott wrote:

Now that's putting the "senior" in "senior project" (sorry, I couldn't
resist. I was born in '62 -- you're young).

So are you. I was born in 52.

Children

I've noticed. Are you EVER going to grow up? ;-)

I was born in 43.

1843? ;-)


--
Greed is the root of all eBay.

 

[pimpom]

Paul E. Schoen wrote:

Hey, I might even *buy* something like that! I can make it
myself,
but I know I never will.

Ah. I guess most of us have projects floating at the back of our
minds, some of them likely to be really useful. But we never get
around to actually making them.