EDAboard.com | EDAboard.de | EDAboard.co.uk | WTWH Media

Clock-Radio gaining time

Ask a question - edaboard.com

elektroda.net NewsGroups Forum Index - Electronics AUS - Clock-Radio gaining time

Goto page 1, 2  Next

Daniel60
Guest

Tue May 08, 2018 11:45 am   



(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I had to rely on it to wake me up for an early morning appointment, I'd
be being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that the
Mains supply frequency, here, was at a slightly higher frequency than my
former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR is
keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
From my having taught Electronics twenty or more years ago, I'd expect
the PLL circuit to consist of a crystal controlled circuit with a
trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the circuitry
of my Clock-Radio to use a reverse-biased PN junction with-in an IC as
the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart from
the fact that the clock-radio is dying, does this mean that this PN
junction is most likely the problem?? Or could there be another cause??

--
Daniel

Trevor Wilson
Guest

Tue May 08, 2018 9:45 pm   



On 8/05/2018 7:51 PM, Daniel60 wrote:
Quote:
(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I had to rely on it to wake me up for an early morning appointment, I'd
be being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that the
Mains supply frequency, here, was at a slightly higher frequency than my
former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR is
keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
From my having taught Electronics twenty or more years ago, I'd expect
the PLL circuit to consist of a crystal controlled circuit with a
trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the circuitry
of my Clock-Radio to use a reverse-biased PN junction with-in an IC as
the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart from
the fact that the clock-radio is dying, does this mean that this PN
junction is most likely the problem?? Or could there be another cause??


**There are, generally, only three types of clock/radios:

1) Mains frequency derived types. These things are horrible. Unplug them
for a minute and you have to reset the time. If the mains frequency is a
little low, they lose time. They can respond to mains control tones
(used to turn on/off water heaters et al) by gaining time.
2) Crystal locked types. Somewhat less common, but far superior. I
searched high and low for one for my partner 25 years ago and found a
rip-snorter from Sony for US$25.99. Unplug it for up to a couple of
hours and it still keeps excellent time.
3) Those fitted with DAB+ radios. Best of all, IMO. You don't even need
to set the time! It's all automatic, as the clock locks onto time
signals inherent to the DAB+ radio system.

Your clock/radio is probably type 1. Time to dump it.
--
Trevor Wilson
www.rageaudio.com.au

Computer Nerd Kev
Guest

Wed May 09, 2018 12:45 am   



Daniel60 <daniel47_at_eternal-september.org> wrote:
Quote:
(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I had to rely on it to wake me up for an early morning appointment, I'd
be being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that the
Mains supply frequency, here, was at a slightly higher frequency than my
former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR is
keeping reasonable time!


PVR will be using a crystal as the frequency reference. Your clock radio
(if mains powered) will probably be using the mains frequency. Other
people may use battery powered clocks, or don't think the deficiencies
in their clock radio is a worthy topic of conversation.

Otherwise it could be some locally induced noise on the mains supply.
Sillicon Chip published a circuit to monitor mains frequency in the
reader submissions section many years ago. I've long been meaning to
build something based on it.

Quote:
So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
From my having taught Electronics twenty or more years ago, I'd expect
the PLL circuit to consist of a crystal controlled circuit with a
trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the circuitry
of my Clock-Radio to use a reverse-biased PN junction with-in an IC as
the "trimmer capacitor" of the PLL circuit.


No PLL, just digital logic counting mains cycles. Look up the datasheet
for the LM8363 which was one of the LSI chips custom designed for use
in mains powered clock radios. It so happens I've got a couple of them
sitting next to me - I still haven't figured out where to file them in
my IC stockpile.

Quote:
If my Clock-Radio is gaining time (a minute or two each day), apart from
the fact that the clock-radio is dying, does this mean that this PN
junction is most likely the problem?? Or could there be another cause??


I guess it's possible that the mains transition detector is dying and
causing the logic to mis-count intermittantly. Though it could also be
your mains power frequency or maybe local noise along the power line
running to it.

--
__ __
#_ < |\| |< _#

Computer Nerd Kev
Guest

Wed May 09, 2018 12:45 am   



Trevor Wilson <trevor_at_spamblockrageaudio.com.au> wrote:
Quote:
On 8/05/2018 7:51 PM, Daniel60 wrote:
(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I had to rely on it to wake me up for an early morning appointment, I'd
be being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that the
Mains supply frequency, here, was at a slightly higher frequency than my
former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR is
keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
From my having taught Electronics twenty or more years ago, I'd expect
the PLL circuit to consist of a crystal controlled circuit with a
trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the circuitry
of my Clock-Radio to use a reverse-biased PN junction with-in an IC as
the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart from
the fact that the clock-radio is dying, does this mean that this PN
junction is most likely the problem?? Or could there be another cause??


**There are, generally, only three types of clock/radios:

1) Mains frequency derived types. These things are horrible. Unplug them
for a minute and you have to reset the time. If the mains frequency is a
little low, they lose time. They can respond to mains control tones
(used to turn on/off water heaters et al) by gaining time.


Mine survived about six hours of combined black-out recently and it's
only five minutes fast. It probably depends a lot on the quality of
capacitor used in the backup RC oscillator (and how often you change
the 9V batt.).

Quote:
2) Crystal locked types. Somewhat less common, but far superior. I
searched high and low for one for my partner 25 years ago and found a
rip-snorter from Sony for US$25.99. Unplug it for up to a couple of
hours and it still keeps excellent time.


My watch is "crystal locked" and time still wanders away from it (come
to think of it I just compared the clock radio to it, so perhaps I'm
completely deluded). The mains is supposably syncronised to atomic
clocks, although I don't know the current situation in Australia for
sure in that regard.

Quote:
3) Those fitted with DAB+ radios. Best of all, IMO. You don't even need
to set the time! It's all automatic, as the clock locks onto time
signals inherent to the DAB+ radio system.


Fair enough mor many, but where I live that would probably mean hooking
an aerial up to my clock radio.

--
__ __
#_ < |\| |< _#

Daniel60
Guest

Wed May 09, 2018 8:45 am   



Trevor Wilson wrote on 09/05/18 06:06:
Quote:
On 8/05/2018 7:51 PM, Daniel60 wrote:
(My news server hasn't shown any new posts, here, for about a
fortnight, so to make sure there is still someone, apart from myself,
here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to
be correct, but currently it is approx 70 mins fast, so gaining about
two minutes a day. Gaining time is better than loosing time, as it
means if I had to rely on it to wake me up for an early morning
appointment, I'd be being woken earlier than required. Not that I have
many early morning appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that
the Mains supply frequency, here, was at a slightly higher frequency
than my former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR
is keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
 From my having taught Electronics twenty or more years ago, I'd
expect the PLL circuit to consist of a crystal controlled circuit with
a trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the
circuitry of my Clock-Radio to use a reverse-biased PN junction
with-in an IC as the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart
from the fact that the clock-radio is dying, does this mean that this
PN junction is most likely the problem?? Or could there be another
cause??


**There are, generally, only three types of clock/radios:

1) Mains frequency derived types. These things are horrible. Unplug them
for a minute and you have to reset the time. If the mains frequency is a
little low, they lose time. They can respond to mains control tones
(used to turn on/off water heaters et al) by gaining time.
2) Crystal locked types. Somewhat less common, but far superior. I
searched high and low for one for my partner 25 years ago and found a
rip-snorter from Sony for US$25.99. Unplug it for up to a couple of
hours and it still keeps excellent time.
3) Those fitted with DAB+ radios. Best of all, IMO. You don't even need
to set the time! It's all automatic, as the clock locks onto time
signals inherent to the DAB+ radio system.

Your clock/radio is probably type 1. Time to dump it.


Your type two reminds me that I failed to mention that the Clock-Radio
does have facility to fit a 9v battery, to maintain the time in the case
of a power failure. (Hmm!! I haven't had a battery fitted for some time!
I wonder if that might have a beneficial effect!!)

Your final comment is probably appropriate ... but as I basically only
use it for the radio when I'm waking up, it's still functional enough!!

--
Daniel

keithr0
Guest

Wed May 09, 2018 10:45 am   



On 5/9/2018 6:06 AM, Trevor Wilson wrote:
Quote:
On 8/05/2018 7:51 PM, Daniel60 wrote:
(My news server hasn't shown any new posts, here, for about a
fortnight, so to make sure there is still someone, apart from myself,
here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to
be correct, but currently it is approx 70 mins fast, so gaining about
two minutes a day. Gaining time is better than loosing time, as it
means if I had to rely on it to wake me up for an early morning
appointment, I'd be being woken earlier than required. Not that I have
many early morning appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that
the Mains supply frequency, here, was at a slightly higher frequency
than my former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR
is keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
 From my having taught Electronics twenty or more years ago, I'd
expect the PLL circuit to consist of a crystal controlled circuit with
a trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the
circuitry of my Clock-Radio to use a reverse-biased PN junction
with-in an IC as the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart
from the fact that the clock-radio is dying, does this mean that this
PN junction is most likely the problem?? Or could there be another
cause??


**There are, generally, only three types of clock/radios:

1) Mains frequency derived types. These things are horrible. Unplug them
for a minute and you have to reset the time. If the mains frequency is a
little low, they lose time. They can respond to mains control tones
(used to turn on/off water heaters et al) by gaining time.


Increasingly rare, in fact you'd be hard put to find one these days.

Quote:
2) Crystal locked types. Somewhat less common, but far superior. I
searched high and low for one for my partner 25 years ago and found a
rip-snorter from Sony for US$25.99. Unplug it for up to a couple of
hours and it still keeps excellent time.


This is by far the most common type these day usually running off a
32KHz xtal. There are a boat load of ICs that will run an LCD display or
a stepper motor off one of those xtals.

Quote:
3) Those fitted with DAB+ radios. Best of all, IMO. You don't even need
to set the time! It's all automatic, as the clock locks onto time
signals inherent to the DAB+ radio system.


I've got an internet clock radio that sets its time just the same way as
a PC does. Lots more stations off the internet than off DAB especially
around here - there is no DAB reception.

> Your clock/radio is probably type 1. Time to dump it.

Ian Field
Guest

Wed May 09, 2018 10:45 pm   



"Daniel60" <daniel47_at_eternal-september.org> wrote in message
news:pcrs03$g19$1_at_dont-email.me...
Quote:
(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if I
had to rely on it to wake me up for an early morning appointment, I'd be
being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!


Does your region have anything like MSF/DCF time signals?

Alarm clocks are easy to find - I'm finding the ones with ceiling display
projection a bit more scarce.

Computer Nerd Kev
Guest

Wed May 09, 2018 11:45 pm   



Ian Field <gangprobing.alien1_at_virginmedia.com> wrote:
Quote:
"Daniel60" <daniel47_at_eternal-september.org> wrote in message
news:pcrs03$g19$1_at_dont-email.me...

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if I
had to rely on it to wake me up for an early morning appointment, I'd be
being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

Does your region have anything like MSF/DCF time signals?


Nothing in Australia.

--
__ __
#_ < |\| |< _#

news18
Guest

Thu May 10, 2018 2:45 am   



On Wed, 09 May 2018 22:12:21 +0100, Ian Field wrote:

Quote:
Alarm clocks are easy to find - I'm finding the ones with ceiling
display projection a bit more scarce.


To ask about another feature, has anyone seen a clock "radio" with a usb
port around the traps.

We have a clock radio as an morning alartm device, but I'm well over
listening to the garbage that you get inflicted with by using the radio
part. so I'm wondering if there is a modern version of the old clock-
radio with "Casette player", which we had a few years ago. It would be
nice to wake up to some pleasant music instead of yesterdays stale "news".

Trevor Wilson
Guest

Thu May 10, 2018 3:45 am   



On 10/05/2018 11:00 AM, news18 wrote:
Quote:
On Wed, 09 May 2018 22:12:21 +0100, Ian Field wrote:

Alarm clocks are easy to find - I'm finding the ones with ceiling
display projection a bit more scarce.

To ask about another feature, has anyone seen a clock "radio" with a usb
port around the traps.

We have a clock radio as an morning alartm device, but I'm well over
listening to the garbage that you get inflicted with by using the radio
part. so I'm wondering if there is a modern version of the old clock-
radio with "Casette player", which we had a few years ago. It would be
nice to wake up to some pleasant music instead of yesterdays stale "news".


**Dunno about USB, but there are shit-loads of the things that have a
dock for a 'phone, so you can play whatever is loaded on your 'phone..
With 'phone docking capability, one would think it would be easy enough
to add USB.

Well, I just had a bit of a look and I can only find USB charging. This
one looks interesting:

https://www.kgelectronic.com.au/p/Electronics-and-Home-Entertainment/HiFi-Audio/Radios/Alarm-Clock-Radios/Qi-Wireless-Digital-Dual-Alarm-Clock-Bluetooth-NFC/SPK-QC001?gclid=EAIaIQobChMIw5qTloT62gIVxiMrCh3T2AAOEAQYASABEgIigvD_BwE


--
Trevor Wilson
www.rageaudio.com.au

Computer Nerd Kev
Guest

Thu May 10, 2018 12:45 pm   



news18 <news18_at_woa.com.au> wrote:
Quote:
On Wed, 09 May 2018 22:12:21 +0100, Ian Field wrote:

Alarm clocks are easy to find - I'm finding the ones with ceiling
display projection a bit more scarce.

To ask about another feature, has anyone seen a clock "radio" with a usb
port around the traps.


Maybe a mains timer powering regular MP3 player? You'd have to have
a separate clock to read the time from though.

--
__ __
#_ < |\| |< _#

Jasen Betts
Guest

Fri May 11, 2018 6:45 am   



On 2018-05-09, Computer Nerd Kev <not_at_telling.you.invalid> wrote:
Quote:
Ian Field <gangprobing.alien1_at_virginmedia.com> wrote:
"Daniel60" <daniel47_at_eternal-september.org> wrote in message
news:pcrs03$g19$1_at_dont-email.me...

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if I
had to rely on it to wake me up for an early morning appointment, I'd be
being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

Does your region have anything like MSF/DCF time signals?

Nothing in Australia.


yeah, nothing except for satellite time signals (GPS etc).
also GSM if you count that.

I once tuned to WWVH on 10MHz using an old shortwave set and a "random" wire
antenna but that was before computers went that fast, and the only
things with switched mode PSUs were TVs at ~16Khz. also that was not from
Australia either that was from Christchurch NZ

--
ت

Daniel60
Guest

Fri May 11, 2018 8:45 am   



Daniel60 wrote on 08/05/18 19:51:
Quote:
(My news server hasn't shown any new posts, here, for about a fortnight,
so to make sure there is still someone, apart from myself, here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I had to rely on it to wake me up for an early morning appointment, I'd
be being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that the
Mains supply frequency, here, was at a slightly higher frequency than my
former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR is
keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
From my having taught Electronics twenty or more years ago, I'd expect
the PLL circuit to consist of a crystal controlled circuit with a
trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the circuitry
of my Clock-Radio to use a reverse-biased PN junction with-in an IC as
the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart from
the fact that the clock-radio is dying, does this mean that this PN
junction is most likely the problem?? Or could there be another cause??

Thanks for all the responses.


You know how "they" say you should quieten your mind as you try to go to
sleep??

Well, last night, as I was trying to drift off to sleep, I was thinking
about my bedside clock-radio and your responses, and I thought .....

Twenty months or so, I moved into this house and about fifteen months
ago, I go twenty solar panels installed.

I expect solar panels produce DC volts which would then have to be
converted to AC volts to power my house and get fed into the power system.

Does anyone, here, know the the frequency of this conversion process is
controlled?? Does the switching circuitry sample the mains to determine
the frequency, or something??

If this frequency is off, slightly, that could explain my clock-radio's
problem. But wouldn't explain why the PVR keeps pretty good time ...
maybe it's set to the T.V. signal, somehow!!

--
Daniel

Ian Field
Guest

Fri May 11, 2018 9:45 pm   



"Jasen Betts" <jasen_at_xnet.co.nz> wrote in message
news:pd39ca$nc3$1_at_gonzo.alcatraz...
Quote:
On 2018-05-09, Computer Nerd Kev <not_at_telling.you.invalid> wrote:
Ian Field <gangprobing.alien1_at_virginmedia.com> wrote:
"Daniel60" <daniel47_at_eternal-september.org> wrote in message
news:pcrs03$g19$1_at_dont-email.me...

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to be
correct, but currently it is approx 70 mins fast, so gaining about two
minutes a day. Gaining time is better than loosing time, as it means if
I
had to rely on it to wake me up for an early morning appointment, I'd
be
being woken earlier than required. Not that I have many early morning
appointments to attend in any case!!

Does your region have anything like MSF/DCF time signals?

Nothing in Australia.

yeah, nothing except for satellite time signals (GPS etc).
also GSM if you count that.


EPE in the UK, which buys in most of its projects from SC has done at least
one GPS and/or sat timepiece.

may be listed as a frequency standard, but pretty sure there was a display
clock add on at some point.

Trevor Wilson
Guest

Fri May 11, 2018 10:45 pm   



On 11/05/2018 5:22 PM, Daniel60 wrote:
Quote:
Daniel60 wrote on 08/05/18 19:51:
(My news server hasn't shown any new posts, here, for about a
fortnight, so to make sure there is still someone, apart from myself,
here .... ;-P )

My bedside Clock-Radio is gaining time. Back when we dropped out of
Daylight Saving at the beginning of April, I expect I adjusted it to
be correct, but currently it is approx 70 mins fast, so gaining about
two minutes a day. Gaining time is better than loosing time, as it
means if I had to rely on it to wake me up for an early morning
appointment, I'd be being woken earlier than required. Not that I have
many early morning appointments to attend in any case!!

So I ask, "What might cause my 25-30 year old Clock-Radio to start
gaining time??"

About eighteen months ago, I moved about 200km, so, it could be that
the Mains supply frequency, here, was at a slightly higher frequency
than my former location, but then why isn't everyone in this location
complaining about their clocks gaining time?? And the clock on my PVR
is keeping reasonable time!

So I'm guessing the Mains Supply Frequency is O.K.!!

That more or less points at the Phase Locked Loop in the Clock-Radio.
 From my having taught Electronics twenty or more years ago, I'd
expect the PLL circuit to consist of a crystal controlled circuit with
a trimmer capacitor ... and it's this "trimmer" that is my suspect!!

Back when I was teaching, we taught CB Radio circuits that included
discrete physical trimmer capacitors, but, I would expect the
circuitry of my Clock-Radio to use a reverse-biased PN junction
with-in an IC as the "trimmer capacitor" of the PLL circuit.

If my Clock-Radio is gaining time (a minute or two each day), apart
from the fact that the clock-radio is dying, does this mean that this
PN junction is most likely the problem?? Or could there be another
cause??

Thanks for all the responses.

You know how "they" say you should quieten your mind as you try to go to
sleep??

Well, last night, as I was trying to drift off to sleep, I was thinking
about my bedside clock-radio and your responses, and I thought .....

Twenty months or so, I moved into this house and about fifteen months
ago, I go twenty solar panels installed.

I expect solar panels produce DC volts which would then have to be
converted to AC volts to power my house and get fed into the power system.

Does anyone, here, know the the frequency of this conversion process is
controlled?? Does the switching circuitry sample the mains to determine
the frequency, or something??


**The frequency and phase of the converter MUST be VERY carefully
controlled to match the AC mains. If not, all sorts of bad things occur.

Quote:

If this frequency is off, slightly, that could explain my clock-radio's
problem. But wouldn't explain why the PVR keeps pretty good time ...
maybe it's set to the T.V. signal, somehow!!


**And again: Your problem likely lies with off-peak controllers. They
operate via a (usually) 400Hz tone which is transmitted down the mains
every few seconds late at night and early in the morning.

Buy a crystal-locked clock radio, or, better still, buy one with DAB+
radio. Problem solved.

--
Trevor Wilson
www.rageaudio.com.au

Goto page 1, 2  Next

elektroda.net NewsGroups Forum Index - Electronics AUS - Clock-Radio gaining time

Ask a question - edaboard.com

Arabic version Bulgarian version Catalan version Czech version Danish version German version Greek version English version Spanish version Finnish version French version Hindi version Croatian version Indonesian version Italian version Hebrew version Japanese version Korean version Lithuanian version Latvian version Dutch version Norwegian version Polish version Portuguese version Romanian version Russian version Slovak version Slovenian version Serbian version Swedish version Tagalog version Ukrainian version Vietnamese version Chinese version Turkish version
EDAboard.com map