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Build alarm clock

J

jeffrey

Jan 1, 1970
0
I want to build a alarm clock that will start counting up when it is
triggered. (e.g., at 5AM, it will go off and start counting 1 second,
2 second.) I can't seem to be able to find clocks like these. (I know
there are timers that will start counting up, but not clocks)

A Radio Shack employee suggested that I buy two clock-timers and
connect them. The clock on one will trigger the stopwatch on the
other. How would I go about doing this?

I've looked online for alarm clock building plans, but I haven't been
too successful. I don't have much experience in this. Any help is
appreciated.

I need to be able make several of these count-up alarm clocks. The
cheaper, the better. The easier, the better.

Thanks.
 
E

ehsjr

Jan 1, 1970
0
jeffrey said:
I want to build a alarm clock that will start counting up when it is
triggered. (e.g., at 5AM, it will go off and start counting 1 second,
2 second.) I can't seem to be able to find clocks like these. (I know
there are timers that will start counting up, but not clocks)

A Radio Shack employee suggested that I buy two clock-timers and
connect them. The clock on one will trigger the stopwatch on the
other. How would I go about doing this?

I've looked online for alarm clock building plans, but I haven't been
too successful. I don't have much experience in this. Any help is
appreciated.

I need to be able make several of these count-up alarm clocks. The
cheaper, the better. The easier, the better.

Thanks.

You didn't specify analog or digital clock. I made the worlds
simplest mod ? to a small quartz analog travel clock to start
when triggered. I use it to time how long it takes to discharge
a battery to a specific voltage with a given load. The clock
runs from a 1.5 volt AA cell. I stuffed a small strip of double
sided pc board between the battery + and the contact in the
battery compartment. The pc board sticks out of the back of the
clock. A wire is soldered to each side of the PC board - when
the wires are connected (by whatever - relay, switch, scr etc)
the clock runs. By setting it at exactly 12:00:00 before starting,
you have essentially a second counter that will last for 12 hours.

Like this:

-------------- ||
| AA }||{ < contact in clock battery compartment
-------------- ||
|| < double sided pc bo0ard
+----||----+
| |
| +---- < wires to
+--------------- < switch/relay/etc

Electronic Goldmine has clocks like the one I used: item #G14709
http://www.goldmine-elec.com/default.htm

Ed
 
W

William P.N. Smith

Jan 1, 1970
0
jeffrey said:
I want to build a alarm clock that will start counting up when it is
triggered. (e.g., at 5AM, it will go off and start counting 1 second,
2 second.) I can't seem to be able to find clocks like these. (I know
there are timers that will start counting up, but not clocks)

I'm pretty sure the clocks at http://countdownclock.com/ will start
counting up after they hit their target. I've got a Y2K clock from
them kicking around somewhere, and I seem to remember this behavior.
Check with them to be sure...

They start at $13 for the blank "make your own" clocks...
 
J

Jeffrey

Jan 1, 1970
0
I was planning on using a digital clock, but will use analog if it's
easier. I don't understand what exactly your device does.

I want to build an alarm clock that will trigger a stopwatch when it
goes off. (Meaning, at 5AM, the buzzer will beep and start counting
up.)
 
E

ehsjr

Jan 1, 1970
0
Jeffrey said:
I was planning on using a digital clock, but will use analog if it's
easier. I don't understand what exactly your device does.

I want to build an alarm clock that will trigger a stopwatch when it
goes off. (Meaning, at 5AM, the buzzer will beep and start counting
up.)

Say you set the alarm clock (any alarm clock) for 5:00 A.M.
It goes off, at 5:00 A.M. Why do you need another
clock/stopwatch/counter to count the seconds? The original
alarm clock keeps running, so you can get the time directly
from it.

That said, if you must have a second clock to count the time,
what I posted originally does that. It does not start counting
until it is triggered. Once triggered, it keeps on counting
until the trigger is removed.

The alarm in the clocks in the link I posted is piezo. The
signal that makes the piezo sound can turn a transistor or
comparator on or off, and that can be used to control whatever
you want to use as your counter, either directly or indirectly.

We need to understand what you are trying to accomplish.
As pointed out, merely counting the seconds after an alarm
clock rings is a function already available from the clock.
We also need to know the anticipated duration. As mentioned
in the previous post, a simple analog clock is good for only
12 hours.

Ed
 
J

jeffrey

Jan 1, 1970
0
I am a high school student and need this for a science fair experiment.

I want to be able to record exactly how long it will take for the
person to wake up. As soon as the buzzer wakes them up, they will
press the button to stop the stopwatch.

So at a predetermined time at night (say, 5AM, or 2AM, or whatever),
the buzzer will go off and a stopwatch will start counting up. As soon
as the person wakes up, they will press a button to stop the
counting-up. They will record whatever the stopwatch says on a sheet
of paper. (Or, if possible, the time will be stored onto a memory
chip.)

I need to make this device as dummy-proof as possible, so many students
will participate in my experiment. It needs to be as cheap as possible
to build and it needs to be very easy to use (All they have to do is
press a button and the time shows up. They don't need to set anything,
or do anything whatsoever.)
 
E

ehsjr

Jan 1, 1970
0
jeffrey said:
I am a high school student and need this for a science fair experiment.

I want to be able to record exactly how long it will take for the
person to wake up. As soon as the buzzer wakes them up, they will
press the button to stop the stopwatch.

So at a predetermined time at night (say, 5AM, or 2AM, or whatever),
the buzzer will go off and a stopwatch will start counting up. As soon
as the person wakes up, they will press a button to stop the
counting-up. They will record whatever the stopwatch says on a sheet
of paper. (Or, if possible, the time will be stored onto a memory
chip.)

I need to make this device as dummy-proof as possible, so many students
will participate in my experiment. It needs to be as cheap as possible
to build and it needs to be very easy to use (All they have to do is
press a button and the time shows up. They don't need to set anything,
or do anything whatsoever.)

Ok - I can give you part of it. First, break it down into
3 pieces:

------- --------- ---------
| Alarm | | Control | | Elapsed |
| |========>| |======>| |
| Clock | | Logic | | Timer |
------- --------- ---------

The alarm clock is a battery powered (*important* for safety)
travel alarm clock you can buy. You can also buy the elapsed
timer. See the web sites below for possible examples.
http://www.seniorshops.com/multitimer.html
http://fantes.com/timers.htm

The control logic input is as follows:

+Vcc ---------------+--------+
| |k
[Relay] [1N4001]
| |
+--------+
Alarm |
Clock /c
Piezo + ---[1K]----| NPN 2N3904
Buzzer \e
|
Ground

When the alarm rings, the relay will energize;
when the alarm is turned off by the subject, the
relay will de-energize. Ground connects to the
negative side of the supply and the negative
side of the battery in the clock.

If you use a clock/timer/stopwatch other than what
I describe below (for example, one of those on the
links I furnished above), then additional circuitry
will be needed, and cannot be specified without
knowing details about the device you choose.

If you use another battery powered travel clock like
the ones at the Electronic Goldmine link I posted,
then you can connect the relay operating point and
normally open point to the double sided PC board
I mentioned in an earlier post, ans slide that
into the battery compartment of the elapsed time
clock, between the battery + post and the contact
in the battery compartment of the clock. That second
clock will start running when the alarm rings, and stop
running when the subject turns the alarm off.

You *will* need to ensure that the alarm is set before
each test. Whether you let the total time accumulate
on the elapsed timer, or record it each time (and
reset the elapsed timer if you like) is up to how you
want to perform the experiment.

The above approach is about the cheapest/easiest you can
use for your experiment. You can go for a more high-tech
looking project at increased cost/complexity. You can also
go for a higher precision in counting the elapsed time, again
at a higher cost/complexity. You'll need to consider your
budget/skill/time available to decide which way to go.

Ed
 
R

Rich Grise

Jan 1, 1970
0
I am a high school student and need this for a science fair experiment.

I want to be able to record exactly how long it will take for the
person to wake up. As soon as the buzzer wakes them up, they will
press the button to stop the stopwatch.

So at a predetermined time at night (say, 5AM, or 2AM, or whatever),
the buzzer will go off and a stopwatch will start counting up. As soon
as the person wakes up, they will press a button to stop the
counting-up. They will record whatever the stopwatch says on a sheet
of paper. (Or, if possible, the time will be stored onto a memory
chip.)

I need to make this device as dummy-proof as possible, so many students
will participate in my experiment. It needs to be as cheap as possible
to build and it needs to be very easy to use (All they have to do is
press a button and the time shows up. They don't need to set anything,
or do anything whatsoever.)


If you're going to require your test subjects to read the stopwatch, why
can't you just require them to read the time off the clock when they
whap it? Set it for precisely 5:00.00, and if it takes it ten minutes
to wake them up, the clock will say 5:10.00 or whatever.

Good Luck!
Rich
 
J

jeffrey

Jan 1, 1970
0
Thanks. I asked the guy at Radio Shack, and he said that the hardest
part would be finding the relay switch in the alarm clock (the thing
that is triggered when the alarm reaches, say, 5AM). How can I find
that?
 
J

jeffrey

Jan 1, 1970
0
Thanks. I asked the guy at Radio Shack, and he said that the hardest
part would be finding the relay switch in the alarm clock. How can I
find that?
 
R

Rich Grise

Jan 1, 1970
0
Thanks. I asked the guy at Radio Shack, and he said that the hardest
part would be finding the relay switch in the alarm clock (the thing
that is triggered when the alarm reaches, say, 5AM). How can I find
that?

Well, since you've neglected to copy/paste any context, I'm guessing
as to what it is you're talking about here: it has something to do
with triggering something when the alarm goes off. I did that once
by hacking into the clock, and just picked off the pulse where it
triggered the piezo, and fired a retriggerable one-shot with it.
I didn't suppress the piezo sound, since it was for an actual alarm
clock - the way I partied in those days, a wimpy little piezo on
a clock radio wouldn't wake me up, so I built an oscillator - a couple
of monostables, where one changed the frequency of another, so it
went kinda "BRAAABRAWWWBRAAABRAWWWWBRAAABRAWWW" with an 8" 20-watt
speaker.

Good Luck!
Rich
 
J

jeffrey

Jan 1, 1970
0
How'd you pick off the pulse?

As for the context, it's earlier in this thread. I need to build an
alarm clock that would also trigger a stopwatch. As soon as I hear the
buzzer at 3AM, I would slam on the button to stop the stopwatch, and
record the exact amount of time it took me to wake up.
 
R

Rich Grise

Jan 1, 1970
0
How'd you pick off the pulse?

As for the context, it's earlier in this thread.

Yes, but I'm using a real newsreader. It doesn't display whole threads
like google does. All I see is the headers and the one message. When
you learn to copy/paste, you save your readers the inconvenience of
having to go track down what it is you're talking about.

Copying and pasting is really simple - move your mouse cursor to just
before the first word of the thing you're answering, press the left mouse
button, and drag the mouse to the end of the text you want to copy,
highlighting it, and release the mouse button. Hit Control-C. That copies
the highlighted text to your clipboard. Move the mouse cursor down to the
google input box, position it appropriately, (preferably first thing), and
hit Control-V to paste the clipboard. It's so simple, and effortless, and
just imagine the number of people worldwide who might be more likely to
want to participate if you did such a simple, courteous, considerate thing?
I need to build an
alarm clock that would also trigger a stopwatch. As soon as I hear the
buzzer at 3AM, I would slam on the button to stop the stopwatch, and
record the exact amount of time it took me to wake up.

OK, find the transistor that drives the piezo, solder a .001 uF (1 nF)
capacitor to its collector, condition the pulse, probably fire a non-
retriggerable monostable, and start the stopwatch with it. Nothing to
it! :)

Have Fun!
Rich
 
J

jeffrey

Jan 1, 1970
0
Yes, I know how to copy and paste.

OK, find the transistor that drives the piezo, solder a .001 uF (1 nF)
capacitor to its collector, condition the pulse, probably fire a non-
retriggerable monostable, and start the stopwatch with it. Nothing to
it! :)

I just went to Target and bought the cheapest alarm clock they had. It
is a $5 alarm clock and has a radio, no buzzer. I can't find the
transistor. (There's too many little things.)

Thanks, Jeff
 
J

jeffrey

Jan 1, 1970
0
Rich said:
OK, find the transistor that drives the piezo, solder a .001 uF (1 nF)
capacitor to its collector, condition the pulse, probably fire a non-
retriggerable monostable, and start the stopwatch with it. Nothing to
it! :)

I forgot to ask, what is a non-retriggerable monostable?
 
Rich said:
Yes, but I'm using a real newsreader. It doesn't display whole threads
like google does. All I see is the headers and the one message.

A lot of people might call that a crappy newsreader.

I don't understand why all these militant usenet crusaders are always
whining at the google community because we don't clutter up the
internet by sending the same text over and over and over every time we
reply.

Usenet article headers contain all of the information your newsreader
needs to follow the thread back to the original post. If your reader
can't figure that out then you should be whining at the people that
wrote it, or switching to a better one. I used to use pine about six
years ago, and I am pretty sure it had no problem dealing with this.
Heck, I think even netscape could do it back in the 90s.

I've used a bunch of software to browse usenet over the past 15 or so
years, and I think google is just great because now I can see all of my
threads no matter where I am, at a friend's house, on a library pc, or
on any of the other pc's in my house.

But anyway, about the topic...

Alarm clocks are among the most obnoxious devices I've ever taken
apart. They seem to do everything in the most complicated manner
possible. I don't understand the rationale behind their design because
it seems a $2 microcontroller, a crystal, and some LEDs would do what
apparently takes a hundred or more components in a $9 alarm clock from
Wal-Mart. It's almost as if they don't want you to reverse-engineer
their product and discover the secret of counting to sixty.

So if you are up to the challenge, and have a little bit of time to
work on it, you might consider building a clock from scratch. It's not
very hard to do (or very expensive), and I happen to be developing a
"build-your-own-alarm-clock" project for engineering students at my
university. I'd be happy to send you a copy of the source code or even
a few programmed chips. It wouldn't be very hard to tweak the
programming to do what you want. In return maybe you and your teachers
could write us a nice letter that we could show to the money people to
prove that we're actually doing something.

You could even build an alarm clock that permanently stores a couple
months worth of wake up time data and lets you read it back later; you
could give out a handful of clocks, and the users could give them back
to you to extract the information from. There'd be no need for them to
remember to write down the times.

Just email me if you're interested.
 
S

Sjouke Burry

Jan 1, 1970
0
jeffrey said:
I forgot to ask, what is a non-retriggerable monostable?
After you fire one , it finishes its cycle , before you
can trigger it again.
 
S

Sjouke Burry

Jan 1, 1970
0
A lot of people might call that a crappy newsreader.

I don't understand why all these militant usenet crusaders are always
whining at the google community because we don't clutter up the
internet by sending the same text over and over and over every time we
reply.
Google choose to ignore general practice.
Now you want the rest of the world to go along
with that? If so ,expect to be ignored by lots of
people,because I for one do not respond to a message
without context.
 
W

William P.N. Smith

Jan 1, 1970
0
jeffrey said:
Thanks. I asked the guy at Radio Shack, and he said that the hardest
part would be finding the relay switch in the alarm clock. How can I
find that?

You don't have to, just rectify the speaker output and use it to
trigger your stopwatch.
 
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