Many books told me that current leads voltage by 90 degrees in capacitor. So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A
Experiment to show that current leads voltage by 90 degrees in capacitor (Using RC circuit and Oscilloscope)
Started by ●August 10, 2020
Reply by ●August 17, 20202020-08-17
yuenhonkeung@gmail.com wrote:> Many books told me that current leads voltage by 90 degrees in capacitor. > So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. > > Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7AGood video. I like the mention of the ground lead connection.
Reply by ●September 3, 20202020-09-03
On Monday, 17 August 2020 at 13:59:41 UTC+8, Cydrome Leader wrote:> yuenho...@gmail.com wrote: > > Many books told me that current leads voltage by 90 degrees in capacitor. > > So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. > > > > Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A > Good video. I like the mention of the ground lead connection.Thanks!
Reply by ●September 9, 20202020-09-09
????????? Edward Yuen <yuenhonkeung@gmail.com> wrote:> On Monday, 17 August 2020 at 13:59:41 UTC+8, Cydrome Leader wrote: >> yuenho...@gmail.com wrote: >> > Many books told me that current leads voltage by 90 degrees in capacitor. >> > So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >> > >> > Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >> Good video. I like the mention of the ground lead connection. > Thanks!I get a good laugh out of half melted ground leads on oscilloscopes.
Reply by ●September 10, 20202020-09-10
On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote:> yuenhonkeung@gmail.com wrote: > > Many books told me that current leads voltage by 90 degrees in capacitor. > > So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. > > > > Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A > > Good video. I like the mention of the ground lead connection.** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. In phase = diagonal line 45 degree shift ( -3db_) = ellipse. 90 degree = circle. ..... Phil
Reply by ●September 11, 20202020-09-11
On 2020-09-10, Phil Allison <pallison49@gmail.com> wrote:> On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote: >> yuenhonkeung@gmail.com wrote: >> > Many books told me that current leads voltage by 90 degrees in capacitor. >> > So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >> > >> > Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >> >> Good video. I like the mention of the ground lead connection. > > ** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. > > In phase = diagonal line > > 45 degree shift ( -3db_) = ellipse. > > 90 degree = circle. >Ah! the memories - back in school in the 1960's, baffling the physics teacher by hooking up the sig. gens to not only the front X input but the Y input at the back - and another on the Z input to get travelling spots.
Reply by ●September 11, 20202020-09-11
On 11.09.20 21:34, Jim Jackson wrote:> On 2020-09-10, Phil Allison <pallison49@gmail.com> wrote: >> On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote: >>> yuenhonkeung@gmail.com wrote: >>>> Many books told me that current leads voltage by 90 degrees in capacitor. >>>> So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >>>> >>>> Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >>> >>> Good video. I like the mention of the ground lead connection. >> >> ** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. >> >> In phase = diagonal line >> >> 45 degree shift ( -3db_) = ellipse. >> >> 90 degree = circle. >> > > Ah! the memories - back in school in the 1960's, baffling the physics > teacher by hooking up the sig. gens to not only the front X input but > the Y input at the back - and another on the Z input to get travelling > spots. >Aaah! Those old times.... I used x,y input, to put text on a scope screen, with 2 dao's from an ordinary 80-286 computer. Worked fine. just visit each point which needed licht, movement from one point to the next, was fast enough to only show as dark lines,
Reply by ●September 13, 20202020-09-13
On 2020-09-11, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote:> On 11.09.20 21:34, Jim Jackson wrote: >> On 2020-09-10, Phil Allison <pallison49@gmail.com> wrote: >>> On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote: >>>> yuenhonkeung@gmail.com wrote: >>>>> Many books told me that current leads voltage by 90 degrees in capacitor. >>>>> So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >>>>> >>>>> Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >>>> >>>> Good video. I like the mention of the ground lead connection. >>> >>> ** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. >>> >>> In phase = diagonal line >>> >>> 45 degree shift ( -3db_) = ellipse. >>> >>> 90 degree = circle. >>> >> >> Ah! the memories - back in school in the 1960's, baffling the physics >> teacher by hooking up the sig. gens to not only the front X input but >> the Y input at the back - and another on the Z input to get travelling >> spots. >> > Aaah! Those old times.... > I used x,y input, to put text on a scope screen, > with 2 dao's from an ordinary 80-286 computer. > Worked fine.Lovely - but in the late 1960's the school I was at didn't have a computer :-) But back in the 40's scopes, well CRTs, were used as RAM for some of the first progammable computers. https://en.wikipedia.org/wiki/Williams_tube> just visit each point which needed licht, > movement from one point to the next, was fast enough > to only show as dark lines,
Reply by ●October 12, 20202020-10-12
Jim Jackson <jj@franjam.org.uk> wrote:> On 2020-09-11, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote: >> On 11.09.20 21:34, Jim Jackson wrote: >>> On 2020-09-10, Phil Allison <pallison49@gmail.com> wrote: >>>> On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote: >>>>> yuenhonkeung@gmail.com wrote: >>>>>> Many books told me that current leads voltage by 90 degrees in capacitor. >>>>>> So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >>>>>> >>>>>> Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >>>>> >>>>> Good video. I like the mention of the ground lead connection. >>>> >>>> ** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. >>>> >>>> In phase = diagonal line >>>> >>>> 45 degree shift ( -3db_) = ellipse. >>>> >>>> 90 degree = circle. >>>> >>> >>> Ah! the memories - back in school in the 1960's, baffling the physics >>> teacher by hooking up the sig. gens to not only the front X input but >>> the Y input at the back - and another on the Z input to get travelling >>> spots. >>> >> Aaah! Those old times.... >> I used x,y input, to put text on a scope screen, >> with 2 dao's from an ordinary 80-286 computer. >> Worked fine. > > Lovely - but in the late 1960's the school I was at didn't have a > computer :-) > > But back in the 40's scopes, well CRTs, were used as RAM for some of the > first progammable computers. > > https://en.wikipedia.org/wiki/Williams_tube > >> just visit each point which needed licht, >> movement from one point to the next, was fast enough >> to only show as dark lines,When did they stop making those memory CRT tubes for scopes and raster display for old computers?
Reply by ●October 12, 20202020-10-12
Cydrome Leader <presence@mungepanix.com> wrote:> Jim Jackson <jj@franjam.org.uk> wrote: >> On 2020-09-11, Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote: >>> On 11.09.20 21:34, Jim Jackson wrote: >>>> On 2020-09-10, Phil Allison <pallison49@gmail.com> wrote: >>>>> On Monday, August 17, 2020 at 3:59:41 PM UTC+10, Cydrome Leader wrote: >>>>>> yuenhonkeung@gmail.com wrote: >>>>>>> Many books told me that current leads voltage by 90 degrees in capacitor. >>>>>>> So, I designed an experiment to show that it is true. You can do the experiment at home or in the laboratory. >>>>>>> >>>>>>> Here is my experiment in youtube: https://www.youtube.com/watch?v=wjQsyLv0X7A >>>>>> >>>>>> Good video. I like the mention of the ground lead connection. >>>>> >>>>> ** If the presenter had simply used an analogue scope - he could have employed a Lissajous pattern to prove the fact is a few seconds. >>>>> >>>>> In phase = diagonal line >>>>> >>>>> 45 degree shift ( -3db_) = ellipse. >>>>> >>>>> 90 degree = circle. >>>>> >>>> >>>> Ah! the memories - back in school in the 1960's, baffling the physics >>>> teacher by hooking up the sig. gens to not only the front X input but >>>> the Y input at the back - and another on the Z input to get travelling >>>> spots. >>>> >>> Aaah! Those old times.... >>> I used x,y input, to put text on a scope screen, >>> with 2 dao's from an ordinary 80-286 computer. >>> Worked fine. >> >> Lovely - but in the late 1960's the school I was at didn't have a >> computer :-) >> >> But back in the 40's scopes, well CRTs, were used as RAM for some of the >> first progammable computers. >> >> https://en.wikipedia.org/wiki/Williams_tube >> >>> just visit each point which needed licht, >>> movement from one point to the next, was fast enough >>> to only show as dark lines, > > When did they stop making those memory CRT tubes for scopes and raster > display for old computers?correction, vector displays.
