Battery doorbell local repeater?...

[Tim R]

On Tuesday, October 27, 2020 at 10:29:39 AM UTC-4, Peter W. wrote:

30 year old Maytag and can\'t get parts, but then it started working again..

https://www.partselect.com/Maytag-Washer-Timers.htm

https://www.partsimple.com/may-wp22004189.html?gclid=Cj0KCQjwit_8BRCoARIsAIx3Rj4vL_WajLBrHLk3CWogi7WivJECirdblL1X0k31mWSCwLBoDPqJo1gaAjY9EALw_wcB

https://www.youtube.com/watch?v=IRtHni3LuXQ

I doubt if there is a part or piece in any Maytag of similar vintage that cannot be found somewhere, and in short order. We have a Maytag dryer at our summer house, and just replaced the belt, rollers, idler and motor with new parts (made in Mexico and the USA) all for less than $100 installed (by me). It was made in 1971.

They really really don\'t make them like that anymore.

And for very good reason: 30 - 45 gallons of water per load. Up to 2 gallons of water left behind (full load) that has to be dried. And more. But, they do work well, when they work.

Peter Wieck
Melrose Park, PA

I did go to those websites and find my part number, only to see them all marked \"out of stock.\"

But then the problem solved itself, so I\'m fine.

If I get another 20 years out of it, that\'s probably more than I have left anyway! Hee, hee.

But appliances controlled with expensive electronic boards, like modern refrigerators, washers and dryers, scare me. Power fluctuations take them out so easily. I hate extended warranties but these may be necessary for some equipment. That mechanical timer could be replaced, with some effort for one that didn\'t quite fit maybe. Or I could put 8 toggle switches in a box and do it manually if I had to. Once a board goes I\'m stuck.

 

[T i m]

On Mon, 26 Oct 2020 10:45:04 -0700 (PDT), Tim R <timothy42b@aol.com>
wrote:

On Monday, October 26, 2020 at 1:38:41 PM UTC-4, Ralph Mowery wrote:
In article <f154b2a6-021c-4824-8893-851434c464a0o@googlegroups.com>,
timothy42b@aol.com says...

Hey, I like it, but we can complicate it more. I think we need a Raspberry Pi or an Arduino in the circuit controlling it.



Outside of the programming the Arduino is very simple to use for many
things. They can be bought for less than $ 5 from many places in China.

That is often less expensive than many of the relays it would take to do
the job.

I need to learn more about that; this is one of those technical advances that kind of sneaked by me. I was trying to figure out if I could replace my washer timer with something like that, 30 year old Maytag and can\'t get parts, but then it started working again.

snip

I setup an Arduino (Uno) as the heart of a semi-automated controller
for my BIL\'s extensive model railway layout.

The test track I have here is just a 3m straight length of (OO) track
on a bit of timber with a small passing place in the middle section,
joined to the main line with a couple of sets of points.

There are diodes in one track leg near the ends to kill the power to
the loco if it was to overrun (but allowing it to reverse out).

There are 4 coded IR sensors on the track, two near the ends, two just
outside the points.

Arduino ramps up the PWM, loco pulls away and accelerates (with
inertia) to full speed till it passes the sensor past the distant
points then decelerates (again with inertia) and then creeps to the
furthest sensor then stops.

The points change (capacitor discharge via electronic bridge drivers)
then the loco pulls away, round the bypass and to the other end.

Rinse / repeat.

The idea was to have some automated bits of track that ran stuff at
the back of his main layout, just to keep something running while he
was working on the layout or running other stuff himself.

The full project was going to be a main line with two sidings at each
end.

The track would be broken up into at least 5 sections, the main run
and the 4 sidings. All 5 could be driven independently (but as one)
and each section \'sensed\' for current draw to determine occupancy /
transition.

3 locos (probably railcars / trams) could be placed on the track, two
in any of the 4 \'ends\' and one on the main line.

On startup, the Arduino would test each section of track for occupancy
(test current pulse), set the points to one of the empty sidings and
drive any loco on the main line into an empty siding.

Now it would randomly select one of the two trains facing the empty
siding at the remote end and set the live line to that siding. It
would then slowly run out onto the main line (past a sensor),
accelerate to full speed (user setable with a pot) to the remote
sensor then slowing though the points and to the end on the empty
siding. We could add a halt / station in the middle if we wanted.

Re evaluate and run again, either randomly or cycling though all three
locos / units.. ;-)

During out initial trials we learned we would probably have to select
a small subset of similar spec models from his extensive collection to
ensure the performance of each loco was similar.

Because he has quite a collection, he really didn\'t want to go
digital, hence all the intelligence had to be in the track.

We might also need to use the Arduino to drive an independent PWM
controller with feedback, to allow better control.

I have an Arduino Mega running the 3D printer I built a few years
back. ;-)

I have a Raspberry Pi3B running Open Media Vault (NAS) on a 3TB USB
drive and another running TVHeadend with a couple of HD TV tuners.

All good fun. ;-)

Cheers, T i m

 

[T i m]

On Mon, 26 Oct 2020 23:03:09 +1100, Chris Jones
<lugnut808@spam.yahoo.com> wrote:

<snip>

I didn\'t know if the buzzer trigger could / should be done by a self
latching circuit of some sort or if one should use a zener to manage
the voltage allowing a better release action?

Do you even need any trigger/latching circuit?

Possibly not, with the right solution. ;-)

Often doorbells only make
a sound when the button is pressed,

This one is just a solenoid hitting one chime (Ding) and then dropping
back to the other (dong) when the button is released.

so the visitor should not be
bothered by that, and it would not require such a trigger circuit.

Ok ...

Why not do pretty much exactly what you already suggested:

Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in
series, they are quite small and should withstand 6V even without
equalising resistors), charge the capacitor from the existing doorbell
wiring via a 1N4004...1N4007 diode,

Ok, so when I first hooked it up it will pull the bell in \'Ding\' and
hold it in till the charging current dropped back enough to allow the
solenoid to release (which might be slow so we might not ever hear a
clear \'dong\')?

and put a piezo or mechanical buzzer
connected in parallel with the diode in the direction with the positive
of the buzzer connected to the cathode of the diode. During charging,
the buzzer will experience 0.7V of reverse bias which probably won\'t
bother it, and when the button is pressed, the diode is reverse biased
and the buzzer receives whatever voltage the capacitor was charged to.

Ok. I follow that.

For simplicity, don\'t bother with any extra series resistor to limit the
charging current, as that would expose the buzzer to more reverse bias,

What if the buzzer was (across your diode) in series ... with another
reversed diode and resistor in parallel?

eg, charging current passes though original diode / buzzer, combo,
through the resistor and into the cap. Then when the button is pressed
the cap charge passes through the second diode, though the buzzer and
to the switch (and back to the -Ve of the cap etc)?

and it is probably unnecessary after the first charging cycle. The
capacitor won\'t have time to discharge much when the button is pressed,
which means it won\'t take long to recharge either.

What sort of leakage do these caps have Chris?

When the circuit is
initially installed, it might take a while to charge the capacitor,
perhaps a minute or so.

Understood, or I could pre-charge it? ;-)

So you need capacitor, diode, buzzer.

plus another diode and suitable resistor ...

If the existing bell has a lot of inductance, when the button is
released there might be a large voltage kick across the switch.

Well it is a solenoid so it might have a bit.

The
diode ought to catch this so I would not expect it to fry the new piezo
buzzer,

I was hoping to go for a electro mechanical buzzer so that it actually
resonated the door frame a bit, rather than just be a beep in parallel
with the existing doorbell.

but it might alter the sound of the existing doorbell when it
releases.

Not if I get the charging resistor right?

Basically, I don\'t think I need a big cap, just one big enough to
allow the buzzer to sound briefly, just to provide feedback to anyone
outside that the button did work (and ideally I wouldn\'t want it to
run much longer in case they did hold their finger on the button).

I\'ll have to rig something up and see how it goes (and it\'s easier to
find 6V buzzers). ;-)

Cheers, T i m

 

[Peter W.]

https://www.amazon.com/American-Scientific-Buzzer-with-Leads/dp/B003VP0DQ2

Not so hard.

Eschew needless complexity - William of Occam

Peter Wieck
Melrose Park, PA

 

[T i m]

On Wed, 28 Oct 2020 04:41:06 -0700 (PDT), \"Peter W.\"
<peterwieck33@gmail.com> wrote:

https://www.amazon.com/American-Scientific-Buzzer-with-Leads/dp/B003VP0DQ2

Not so hard.

Cool, I\'ve ordered the same thing (and in white) from Amazon UK. ;-)

Eschew needless complexity - William of Occam

Agreed, if at all possible and as long as it works. ;-)

Do you think I\'ll need to limit the voltage across the buzzer (2 (/3)
diodes in series in parallel with the buzzer?) and that the existing
bell draws at least 25mA?

\"* Minimum Input Voltage: 1.3V* Maximum Input Voltage: 2V* Current
Consumption: 25mA* Nominal Output @ 30cm: 75dB* Output Frequency:
400Hz* \"

Cheers, T i m

 

[Chris Jones]

On 28/10/2020 10:45, T i m wrote:

On Mon, 26 Oct 2020 23:03:09 +1100, Chris Jones
lugnut808@spam.yahoo.com> wrote:

snip

I didn\'t know if the buzzer trigger could / should be done by a self
latching circuit of some sort or if one should use a zener to manage
the voltage allowing a better release action?

Do you even need any trigger/latching circuit?

Possibly not, with the right solution. ;-)

Often doorbells only make
a sound when the button is pressed,

This one is just a solenoid hitting one chime (Ding) and then dropping
back to the other (dong) when the button is released.

so the visitor should not be
bothered by that, and it would not require such a trigger circuit.

Ok ...


Why not do pretty much exactly what you already suggested:

Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in
series, they are quite small and should withstand 6V even without
equalising resistors), charge the capacitor from the existing doorbell
wiring via a 1N4004...1N4007 diode,

Ok, so when I first hooked it up it will pull the bell in \'Ding\' and
hold it in till the charging current dropped back enough to allow the
solenoid to release (which might be slow so we might not ever hear a
clear \'dong\')?

and put a piezo or mechanical buzzer
connected in parallel with the diode in the direction with the positive
of the buzzer connected to the cathode of the diode. During charging,
the buzzer will experience 0.7V of reverse bias which probably won\'t
bother it, and when the button is pressed, the diode is reverse biased
and the buzzer receives whatever voltage the capacitor was charged to.

Ok. I follow that.

For simplicity, don\'t bother with any extra series resistor to limit the
charging current, as that would expose the buzzer to more reverse bias,

What if the buzzer was (across your diode) in series ... with another
reversed diode and resistor in parallel?

eg, charging current passes though original diode / buzzer, combo,
through the resistor and into the cap. Then when the button is pressed
the cap charge passes through the second diode, though the buzzer and
to the switch (and back to the -Ve of the cap etc)?

I had considered suggesting such an arrangement, but then I thought that
the simpler option would probably be good enough.

and it is probably unnecessary after the first charging cycle. The
capacitor won\'t have time to discharge much when the button is pressed,
which means it won\'t take long to recharge either.

What sort of leakage do these caps have Chris?

Here is a datasheet. Tens of microamperes or less. I didn\'t know but
they come in voltage ratings above 5.5V so you would only need one
capacitor:
https://au.mouser.com/datasheet/2/40/AVX_SCM-1018838.pdf

When the circuit is
initially installed, it might take a while to charge the capacitor,
perhaps a minute or so.

Understood, or I could pre-charge it? ;-)

So you need capacitor, diode, buzzer.

plus another diode and suitable resistor ...


If the existing bell has a lot of inductance, when the button is
released there might be a large voltage kick across the switch.

Well it is a solenoid so it might have a bit.

The
diode ought to catch this so I would not expect it to fry the new piezo
buzzer,

I was hoping to go for a electro mechanical buzzer so that it actually
resonated the door frame a bit, rather than just be a beep in parallel
with the existing doorbell.

but it might alter the sound of the existing doorbell when it
releases.

Not if I get the charging resistor right?

True. That\'s the main advantage I can think of for putting a charging
resistor. There might be an argument for using a zener diode rather than
a rectifier diode in parallel with the charging resistor, as I don\'t
know whether breakdown might be destructive for a diode not intended as
a zener.

Basically, I don\'t think I need a big cap, just one big enough to
allow the buzzer to sound briefly, just to provide feedback to anyone
outside that the button did work (and ideally I wouldn\'t want it to
run much longer in case they did hold their finger on the button).
Yes, a smaller capacitor would do if you have a suitable one on hand.

I\'ll have to rig something up and see how it goes (and it\'s easier to
find 6V buzzers). ;-)

I think you should try it and please report back how it goes.

 

[peter...@gmail.com]

Do you think I\'ll need to limit the voltage across the buzzer (2 (/3)
diodes in series in parallel with the buzzer?) and that the existing
bell draws at least 25mA?

That would depend very much on how long your delivery individual holds down the button. But a couple-of-ohms, 1-watt resistor, or so, in parallel to the buzzer should give all the protection you need. One watt is crazy-overkill, but cheap enough.

Peter Wieck
Melrose Park, PA

 

[T i m]

On Thu, 29 Oct 2020 03:43:19 -0700 (PDT), \"peter...@gmail.com\"
<peterwieck9@gmail.com> wrote:

Do you think I\'ll need to limit the voltage across the buzzer (2 (/3)
diodes in series in parallel with the buzzer?) and that the existing
bell draws at least 25mA?

That would depend very much on how long your delivery individual holds down the button.

If it\'s anything like the Hermes delivery at 8 last night, too long
(or two many times). ;-(

>But a couple-of-ohms, 1-watt resistor, or so, in parallel to the buzzer should give all the protection you need.

So if using a resistor in that role I really need to match the
resistance to the resistance of the solenoid to give me the right
voltage drop over the buzzer (potential divider), hoping the worst
case is not too much voltage across the buzzer and when the batteries
are on the way out, enough for the buzzer bit to still work?

If I had a suitably low value (ww?) pot, I could put that across the
buzzer then tune it for the best sound with the Ni-Mh cells (then
replace it with a fixed resistor etc)?

> One watt is crazy-overkill, but cheap enough.

Why wouldn\'t a \'voltage\' regulated solution be better, given how
little voltage we have spare to play with and the fact that the
voltage will change with time?

It looks like you can get 1.5V zeners so as long as they can manage
the current though the existing bell and the back EMF etc, wouldn\'t
that be the more subtle way of managing it all?

<idea>

I just stuck my DMM across the contacts on the bell push (at the bell
itself) and with a 6V battery supply I measure ~750mA (dropping to
~730 after a few seconds). That puts the bell solenoid resistance at
around 8 ohms (plus what I would get via the cabling etc).

If the buzzer draws 25mA at 1.5V then the buzzers resistance is around
60 ohms (I know that isn\'t ever going to be a pure resistor, unlike
the saturated solenoid) so adding that in series with the bell is
going to give me around 70 ohms and a maximum current of ~85mA.

That\'s roughly 5V across the buzzer and 1V across the bell.

Putting a 2 ohm resistor in parallel with the buzzer will give me just
over 10 ohms in total, so back up to around 600+mA, and so 1.2V across
the buzzer and 4.8V across the bell (and I know it works with 4.8V\'s
worth of rechargeables. ;-)

However, aren\'t we wasting energy in a resistor system, rather than
clamping voltage using a (say) a zener or is it the same thing?

Cheers, T i m

 

[T i m]

On Thu, 29 Oct 2020 13:57:16 +1100, Chris Jones
<lugnut808@spam.yahoo.com> wrote:

<snip>

and it is probably unnecessary after the first charging cycle. The
capacitor won\'t have time to discharge much when the button is pressed,
which means it won\'t take long to recharge either.

What sort of leakage do these caps have Chris?

Here is a datasheet. Tens of microamperes or less. I didn\'t know but
they come in voltage ratings above 5.5V so you would only need one
capacitor:
https://au.mouser.com/datasheet/2/40/AVX_SCM-1018838.pdf

Interesting, thanks.

Are these the sorts of things they have in these clever capacitive
based vehicle jump starting units?

snip

but it might alter the sound of the existing doorbell when it
releases.

Not if I get the charging resistor right?

True. That\'s the main advantage I can think of for putting a charging
resistor. There might be an argument for using a zener diode rather than
a rectifier diode in parallel with the charging resistor, as I don\'t
know whether breakdown might be destructive for a diode not intended as
a zener.

Understood.

snip

I\'ll have to rig something up and see how it goes (and it\'s easier to
find 6V buzzers). ;-)

I think you should try it and please report back how it goes.

You should see from elsewhere I\'m going to try the low voltage series
buzzer first and yes, of course I\'ll report back as I can\'t be the
only one in this position who might appreciate a \'simple\' solution?
;-)

Cheers, T i m

 

[Fox\'s Mercantile]

Y\'all are way over thinking this.
Just replace the door bell button with a DPST NO push button.
Then use the other half to do what ever you want.


--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Peter W.]

However, aren\'t we wasting energy in a resistor system, rather than
clamping voltage using a (say) a zener or is it the same thing?

The resistor is on play only when the button is being pushed. So the amount of energy \'wasted\' is negligible.
The buzzer is rated up to two (2) volts. Which suggests that a 1.5 ohm resistor will accommodate voltage swings from the battery and still protect the buzzer.
Resistors are far less complicated (and thereby more reliable) than a diode, more so if that diode is a zener. The idea is to pass enough current to trip the bell solenoid, yet not damage the buzzer.
I am not so sure batteries, buttons, buzzers and bells understand the concept of \"subtle\" on the one hand. They may understand \"elegant\" on the other hand. On the gripping hand, they certainly understand \"simple\".
I am trying to limit the number of parts involved with the least complicated, most efficient solution that uses what is already in place, and also does not involve brain-damage.

Enjoy!

Peter Wieck
Melrose Park, PA

 

[Edward Hernandez]

On Thursday, October 29, 2020 at 8:26:21 AM UTC-5, Fox\'s Mercantile wrote:

Y\'all are way over thinking this.
Just replace the door bell button with a DPST NO push button.
Then use the other half to do what ever you want.


--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Look at you and pony pete working in tandem. You too have come a long way. Keep up the good work.

 

[Edward Hernandez]

On Thursday, October 29, 2020 at 9:09:46 AM UTC-5, Peter W. wrote:

However, aren\'t we wasting energy in a resistor system, rather than
clamping voltage using a (say) a zener or is it the same thing?
The resistor is on play only when the button is being pushed. So the amount of energy \'wasted\' is negligible.
The buzzer is rated up to two (2) volts. Which suggests that a 1.5 ohm resistor will accommodate voltage swings from the battery and still protect the buzzer.
Resistors are far less complicated (and thereby more reliable) than a diode, more so if that diode is a zener. The idea is to pass enough current to trip the bell solenoid, yet not damage the buzzer.
I am not so sure batteries, buttons, buzzers and bells understand the concept of \"subtle\" on the one hand. They may understand \"elegant\" on the other hand. On the gripping hand, they certainly understand \"simple\".
I am trying to limit the number of parts involved with the least complicated, most efficient solution that uses what is already in place, and also does not involve brain-damage.

Enjoy!
Peter Wieck
Melrose Park, PA

There you go Petey! See, it\'s not so hard to be helpful. Just don\'t inject to much of your inner thoughts when you reply. Give only pertinent information like in this example.

 

[Peter W.]

Boo

 

[Fox\'s Mercantile]

On 10/29/20 12:00 PM, Edward Hernandez wrote:
> Look at you and pony pete working in tandem.

You fix that piece of shit charger yet asshole?

--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Edward Hernandez]

On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox\'s Mercantile wrote:

On 10/29/20 12:00 PM, Edward Hernandez wrote:
Look at you and pony pete working in tandem.
You fix that piece of shit charger yet asshole?
--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Hey Gramps. What you mean to say is, \"How else can I serve those in this forum community.\"

 

[Michael Terrell]

On Tuesday, October 27, 2020 at 11:12:19 AM UTC-4, timot...@aol.com wrote:

I did go to those websites and find my part number, only to see them all marked \"out of stock.\"

But then the problem solved itself, so I\'m fine.

If I get another 20 years out of it, that\'s probably more than I have left anyway! Hee, hee.

But appliances controlled with expensive electronic boards, like modern refrigerators, washers and dryers, scare me. Power fluctuations take them out so easily. I hate extended warranties but these may be necessary for some equipment. That mechanical timer could be replaced, with some effort for one that didn\'t quite fit maybe. Or I could put 8 toggle switches in a box and do it manually if I had to. Once a board goes I\'m stuck.

Have you tried https://www.searspartsdirect.com/

 

[Fox\'s Mercantile]

On 10/29/20 2:16 PM, Edward Hernandez wrote:

On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox\'s Mercantile wrote:
On 10/29/20 12:00 PM, Edward Hernandez wrote:
Look at you and pony pete working in tandem.
You fix that piece of shit charger yet asshole?
--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Hey Gramps. What you mean to say is, \"How else can I serve those in this forum community.\"

In other words no. I figured as much.


--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Edward Hernandez]

On Friday, October 30, 2020 at 12:02:58 AM UTC-5, Fox\'s Mercantile wrote:

On 10/29/20 2:16 PM, Edward Hernandez wrote:
On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox\'s Mercantile wrote:
On 10/29/20 12:00 PM, Edward Hernandez wrote:
Look at you and pony pete working in tandem.
You fix that piece of shit charger yet asshole?
--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Hey Gramps. What you mean to say is, \"How else can I serve those in this forum community.\"

In other words no. I figured as much.
--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Have you figured out how to be a better person? You don\'t have to answer. lol. We all know.

 

[Fox\'s Mercantile]

On 10/30/20 8:33 AM, Edward Hernandez wrote:
> Have you figured out how to be a better person?

Only to those that deserve it.
You certainly don\'t.


--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com