Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting on application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive? What is the output load? The output cap is 1,000 uF.
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting on application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive? What is the output load? The output cap is 1,000 uF..
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
The aforementioned resistor failed open-circuit without any external
sign of overheating at all. Bonus points will be awarded for anyone
who can think of a reason why this might have occurred.
On Sunday, August 13, 2023 at 4:52:58?AM UTC-4, Cursitor Doom wrote:
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting on application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive? What is the output load? The output cap is 1,000 uF.
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Have you replaced the resistor yet? I have no idea why it broke, but it\'s not like everything is made perfectly. Have you tried just reflowing the solder? I\'m assuming it\'s surface mount.
On a sunny day (Sun, 13 Aug 2023 09:26:15 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <g73hdi12hmo1amf1uq5ad8poqi4lk5ebk3@4ax.com>:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
Supply ripple filtering
1 Ohm with 2200 uF and what looks like 1 nF parallel to that elco.
13.8 V supply comes in via external wire so may contain any crap.
The 3 dB point of that filter is 1 / (2 * Pi * R * C) = about 72 Hz
See
http://www.learningaboutelectronics.com/Articles/Cut-off-frequency-calculator.php
So does not do much for mains frequency but will for its harmonics and other RF stuff.
On Sunday, August 13, 2023 at 6:26:25â¯PM UTC+10, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
** It provides peak current limiting at the moment the unit is connected to a DC supply - plus a measure of noise filtering thereafter in conjunction with the 2200uF electro.
Should be a composition or WW type, not carbon film, to survive the energy in such surges.
Nothing strange about the original film resistor failing open and invisibly when subjected to 13A spikes lasting a few milliseconds.
On Sun, 13 Aug 2023 02:09:23 -0700 (PDT), Ricky
gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:52:58?AM UTC-4, Cursitor Doom wrote:
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting on
application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive? What
is the output load? The output cap is 1,000 uF.
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Have you replaced the resistor yet? I have no idea why it broke, but it\'s not like everything is made perfectly. Have you
tried just reflowing the solder? I\'m assuming it\'s surface mount.
No, it\'s tru hole. Sorry I thought I\'d linked to a picture as well but
it hasn\'t shown up. Let\'s try that again:
https://disk.yandex.com/i/dE9o0lh937qdrg
It\'s the resistor right next to the largest electro.
On a sunny day (Sun, 13 Aug 2023 12:00:35 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <aqdhdih6bf5r9116ft3ijctfdqguj44qt6@4ax.com>:
On Sun, 13 Aug 2023 02:09:23 -0700 (PDT), Ricky
gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:52:58?AM UTC-4, Cursitor Doom wrote:
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting on
application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive? What
is the output load? The output cap is 1,000 uF.
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Have you replaced the resistor yet? I have no idea why it broke, but it\'s not like everything is made perfectly. Have you
tried just reflowing the solder? I\'m assuming it\'s surface mount.
No, it\'s tru hole. Sorry I thought I\'d linked to a picture as well but
it hasn\'t shown up. Let\'s try that again:
https://disk.yandex.com/i/dE9o0lh937qdrg
It\'s the resistor right next to the largest electro.
Do you measure a short across that capacitor?
That UPC2002H is no longer made, could well be the chip.
The filter could work the other way: prevent audio to cause the 13.8V to change
On Sun, 13 Aug 2023 11:33:12 GMT, Jan Panteltje <alien@comet.invalid
wrote:
On a sunny day (Sun, 13 Aug 2023 12:00:35 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <aqdhdih6bf5r9116ft3ijctfdqguj44qt6@4ax.com>:
On Sun, 13 Aug 2023 02:09:23 -0700 (PDT), Ricky
gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:52:58?AM UTC-4, Cursitor Doom wrote:
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting
on
application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive?
What
is the output load? The output cap is 1,000 uF.
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Have you replaced the resistor yet? I have no idea why it broke, but it\'s not like everything is made perfectly. Have you
tried just reflowing the solder? I\'m assuming it\'s surface mount.
No, it\'s tru hole. Sorry I thought I\'d linked to a picture as well but
it hasn\'t shown up. Let\'s try that again:
https://disk.yandex.com/i/dE9o0lh937qdrg
It\'s the resistor right next to the largest electro.
Do you measure a short across that capacitor?
That UPC2002H is no longer made, could well be the chip.
The filter could work the other way: prevent audio to cause the 13.8V to change
Nope. The caps all test fine for value, ESR and whatnot and there\'s
nothing in that area getting hot either, and that includes the chip.
On a sunny day (Sun, 13 Aug 2023 12:41:10 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <p7ghdil8l6rhq8qe8c7vuvir9vvqe58kcr@4ax.com>:
On Sun, 13 Aug 2023 11:33:12 GMT, Jan Panteltje <alien@comet.invalid
wrote:
On a sunny day (Sun, 13 Aug 2023 12:00:35 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <aqdhdih6bf5r9116ft3ijctfdqguj44qt6@4ax.com>:
On Sun, 13 Aug 2023 02:09:23 -0700 (PDT), Ricky
gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:52:58?AM UTC-4, Cursitor Doom wrote:
On Sun, 13 Aug 2023 01:43:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:
On Sunday, August 13, 2023 at 4:26:25?AM UTC-4, Cursitor Doom wrote:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
My guess would be to act as the R in a pi filter. Hard to say actually. Or maybe the idea is to provide current limiting
on
application of power. The downstream cap seems to be 2,000 uF which is a whopper. How much current does the output drive?
What
is the output load? The output cap is 1,000 uF.
I couldn\'t come up with anything better than the pi filter possibility
either to be honest, but haven\'t done any calcs to see if that would
make any sense or not. This IC directly drives a 2W 8 ohm speaker.
Have you replaced the resistor yet? I have no idea why it broke, but it\'s not like everything is made perfectly. Have you
tried just reflowing the solder? I\'m assuming it\'s surface mount.
No, it\'s tru hole. Sorry I thought I\'d linked to a picture as well but
it hasn\'t shown up. Let\'s try that again:
https://disk.yandex.com/i/dE9o0lh937qdrg
It\'s the resistor right next to the largest electro.
Do you measure a short across that capacitor?
That UPC2002H is no longer made, could well be the chip.
The filter could work the other way: prevent audio to cause the 13.8V to change
Nope. The caps all test fine for value, ESR and whatnot and there\'s
nothing in that area getting hot either, and that includes the chip.
You did say you did not replace the resistor, so then you have no power to that chip,
Else just use your multimeter on highest current range instead of the 1 Ohm for a second
to see what happens, or even a small lightbulb...
WIthout audio that chip should draw very little current, class B likely.
On Sun, 13 Aug 2023 10:33:45 GMT, Jan Panteltje <alien@comet.invalid
wrote:
On a sunny day (Sun, 13 Aug 2023 09:26:15 +0100) it happened Cursitor Doom
cd@notformail.com> wrote in <g73hdi12hmo1amf1uq5ad8poqi4lk5ebk3@4ax.com>:
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
Supply ripple filtering
1 Ohm with 2200 uF and what looks like 1 nF parallel to that elco.
13.8 V supply comes in via external wire so may contain any crap.
The 3 dB point of that filter is 1 / (2 * Pi * R * C) = about 72 Hz
See
http://www.learningaboutelectronics.com/Articles/Cut-off-frequency-calculator.php
So does not do much for mains frequency but will for its harmonics and other RF stuff.
Yeahbut there\'s already a great amount of up-stream filtering from
within the well-screen internal power supply. Where\'s the crap going
to come from?
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.
The aforementioned resistor failed open-circuit without any external
sign of overheating at all. Bonus points will be awarded for anyone
who can think of a reason why this might have occurred.
The aforementioned resistor failed open-circuit without any external
sign of overheating at all. Bonus points will be awarded for anyone
who can think of a reason why this might have occurred.
Gentlemen,
I refer you to this circuit fragment:
https://disk.yandex.com/i/O-4WvVAgNjmNlg
What\'s R30 supposed to achieve? This is right at the top of the
schematic, btw.