Can you help me desing this?

[K.K.]

Dear Sirs,
I'm interested in building a circuit that will give a signal for t1=1
second to a buzzer every 10 seconds (t2=10 seconds), Ta=t1+t2. I'd
prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to
be bridged by the mercury blob, and after a 5 seconds delay, it gives
a signal for t1=1 second to the above buzzer every second (t2=1
second), Tb=t1+t2. The circuit will continue to work at the second
state, T2, for as long as the mercury switch is closed and will return
to the first state, T1, when the mercury switch opens. The circuit
will operate between +6 volts and 9 volts DC. Do you have any idea how
can I build it or something similar? Is there a way to make the buzzer
sound louder?
Thank you very much in advance.

 

[John Fields]

On 13 May 2004 09:26:31 -0700, cs99021@icsd.aegean.gr (K.K.) wrote:

Dear Sirs,
I'm interested in building a circuit that will give a signal for t1=1
second to a buzzer every 10 seconds (t2=10 seconds), Ta=t1+t2. I'd
prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to
be bridged by the mercury blob, and after a 5 seconds delay, it gives
a signal for t1=1 second to the above buzzer every second (t2=1
second), Tb=t1+t2. The circuit will continue to work at the second
state, T2, for as long as the mercury switch is closed and will return
to the first state, T1, when the mercury switch opens. The circuit
will operate between +6 volts and 9 volts DC. Do you have any idea how
can I build it or something similar? Is there a way to make the buzzer
sound louder?

Click on this---> fat7a0pgeii23kpg3fc25o9oif4utn3iom@4ax.com

You can make the 10 second T2 adjustable by replacing R6 with a pot,
and you cam make the buzzer loder by putting it in a resonant housing
driving it with a higher voltage, or buying a louder one.

--
John Fields

 

[Tom Bruhns]

Sounds like a good application of an LM555 type analog timer circuit.
Look at the data sheet and any applications notes you might find. The
"555" timer is made by a lot of different manufacturers.

The circuit might work by having one 555 oscillate with the t1,t2
times you want (this is easy), and causing the mercury switch to begin
a delay of 5 seconds through another 555; when that second 555 "times
out", it injects a higher charging current into the timing capacitor
of the first 555, resulting in a 1sec/1sec on/off time. However,
since that switch could close anywhere in the cycle of the T1 state,
it would not necessarily be 5 seconds exactly until the first beep
after switch closure. You could overcome that with some additional
circuit complexity, where the switch immediately suspends the main
timer. Things start to get complicated if you insist that the timing
be just so. In that case, you could use a tiny microprocessor such as
the PIC12C508, and use its internal clock, and get whatever timing you
want so long as it doesn't have to anticipate anything in the future!
Then you need supply only the power to that IC (which would have to be
regulated to a lower voltage than your 6-9 volts), but there are very
few other parts. Left-over pins could be used to adjust the duration
of the various parts of the timing cycle, even. A 555 circuit could
be very tolerant of power supply voltage changes, as its timing
depends generally only on voltage ratios and not absolute voltages.

Louder: see burglar alarm system horns... You may need some
interface to get between the low-power 555 output and whatever it
takes to drive such a sounder.

Cheers,
Tom

cs99021@icsd.aegean.gr (K.K.) wrote in message news:<d4f617c8.0405130826.5e59fba1@posting.google.com>...

Dear Sirs,
I'm interested in building a circuit that will give a signal for t1=1
second to a buzzer every 10 seconds (t2=10 seconds), Ta=t1+t2. I'd
prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to
be bridged by the mercury blob, and after a 5 seconds delay, it gives
a signal for t1=1 second to the above buzzer every second (t2=1
second), Tb=t1+t2. The circuit will continue to work at the second
state, T2, for as long as the mercury switch is closed and will return
to the first state, T1, when the mercury switch opens. The circuit
will operate between +6 volts and 9 volts DC. Do you have any idea how
can I build it or something similar? Is there a way to make the buzzer
sound louder?
Thank you very much in advance.

 

[N. Thornton]

cs99021@icsd.aegean.gr (K.K.) wrote in message news:<d4f617c8.0405130826.5e59fba1@posting.google.com>...

Dear Sirs,

prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to

use a ball switch rather than mercury. And we're not all sirs.

Regards, NT

 

[John Fields]

On 14 May 2004 04:20:25 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

cs99021@icsd.aegean.gr (K.K.) wrote in message news:<d4f617c8.0405130826.5e59fba1@posting.google.com>...
Dear Sirs,

prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to


use a ball switch rather than mercury. And we're not all sirs.

---
Geez, I distinctly remember him saying that the circuit _will have_ a
mercury switch...

And, yes, some of us are real twats.

--
John Fields

 

[N. Thornton]

John Fields <jfields@austininstruments.com> wrote in message news:<okt9a0peivnvmfp8gul4sbcdep9juqefc9@4ax.com>...

On 14 May 2004 04:20:25 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:
cs99021@icsd.aegean.gr (K.K.) wrote in message news:<d4f617c8.0405130826.5e59fba1@posting.google.com>...

prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to

use a ball switch rather than mercury. And we're not all sirs.

Geez, I distinctly remember him saying that the circuit _will have_ a
mercury switch...

so? If the OP hasnt got the switch yet they can use a ball switch
instead. Valid suggestion no?

And, yes, some of us are real twats.

I see.


Regards, NT

 

[John Fields]

On 15 May 2004 07:30:31 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

John Fields <jfields@austininstruments.com> wrote in message news:<okt9a0peivnvmfp8gul4sbcdep9juqefc9@4ax.com>...
On 14 May 2004 04:20:25 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:
cs99021@icsd.aegean.gr (K.K.) wrote in message news:<d4f617c8.0405130826.5e59fba1@posting.google.com>...

prefer t2 to be adjustable. The circuit will also have a mercury
switch. When the mercury switch is disturbed, causing its contacts to

use a ball switch rather than mercury. And we're not all sirs.

Geez, I distinctly remember him saying that the circuit _will have_ a
mercury switch...

so? If the OP hasnt got the switch yet they can use a ball switch
instead. Valid suggestion no?

---
Sure, unless it's based on that "mercury switches are bad because if
they break they'll kill half of the world's population" bit.
---

And, yes, some of us are real twats.

I see.

---


--
John Fields