Author Topic: Coulometric hourmeters  (Read 680 times)

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 721
  • Karma: +22/-0
    • View Profile
Coulometric hourmeters
« on: May 27, 2024, 08:26:11 AM »
Storage space cleanup revealed a gadget I made about 20 years ago, to demonstrate a "Curtis" type hourmeter.
Full scale in this one is 2500 hours when connected to 12 volts DC.

A glass capillary tube contains a tiny slug of clear electrolyte between two columns of mercury metal.

Last Thursday I replaced the broken 9-volt battery connector, then plugged in a battery to start the clock.
Initial battery voltage is 9.09 V, with 7.48 V across the hourmeter and 1.61 V across the indicator LED.
Current is about 80 microamps.  In a few days we will be able to see how fast the gap is moving, and in which direction.

This gadget was reported at 4hv forum in 2009.
https://4hv.org/e107_plugins/forum/forum_viewtopic.php?p=1&id=77016
« Last Edit: May 28, 2024, 11:06:24 PM by klugesmith »

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 721
  • Karma: +22/-0
    • View Profile
Re: Coulometric hourmeters
« Reply #1 on: May 28, 2024, 11:30:50 PM »
When re-commissioning the demonstration, I guessed at the meter polarity.
Now we see it's "wrong".
In 4.75 days, the gap moved from about 518 hours to about 450 hours on the scale.

The indicated change is -68 hours,  actual elapsed time 114 hours, ratio -0.60.
Consistent with applying -7.2 volts to a 12 volt meter.  We have used about 9 mAh of the battery capacity.

Let's run it backwards for a few more days, and see what happens to the irregularities on mercury column between 350 and 400 on the scale.

[edit] p.s. How do you like that LED at 80 microamps?   I bet we could read a book by its light, in spot diameter of 1 or 2 inches.
« Last Edit: May 28, 2024, 11:39:27 PM by klugesmith »

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 721
  • Karma: +22/-0
    • View Profile
Re: Coulometric hourmeters
« Reply #2 on: June 04, 2024, 10:31:58 PM »
I came here with a question for some applied physics expert, after looking up the number density of conduction electrons in mercury. Then figured it out while typing the question.  Here presented for review.

The only reference I've found is a table at hyperphysics website: http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/fermi.html#c2.
That cites a venerable solid-state physics textbook by Ashcroft and Mermin. 
The value for copper is familiar from drift velocity presentations all over the place:  8.47e22 free_electrons/cm^3.
The values given for Al, Fe, Cu, Ag, and Hg are 3.00, 2.00, 1.00, 1.00, and 2.13 times the atom number densities I computed for the metals. 

Why the non-integer ratio for Hg?   It's listed in table as Hg**, and the double asterisk refers to a unique note "at 78K".
6.5% seemed like a lot for thermal contraction between room temperature and 78 K, but I think it's the real explanation.
Most of the factor is from liquid to solid transition.  The remainder is from change in specific volume, which is always 3x greater than linear dimension change in a solid.  How do they even measure mobile charge density except by Hall effect?  In metals that's a challenge even with very thin films, because density of mobile charge is high, so its velocities are low. (Hall established that its sign is  usually negative, long before electrons were discovered.)

Here is the hourmeter picture near end of day 12.

We've run about 20 mAh through the instrument, so far. 73 coulombs.  If it all went through the electrolyte, we have transferred 5 cubic millimeters of Hg.  I think the capillary ID is too narrow for that, especially considering the optical magnification from thick glass tube.  Must remember to get it x-rayed at my next visit to dentist.  There might be a current divider inside the black box, but what purpose would that serve, compared to just using a higher value metering resistor for 12 volt service?
« Last Edit: June 05, 2024, 01:49:00 AM by klugesmith »

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 721
  • Karma: +22/-0
    • View Profile
Re: Coulometric hourmeters
« Reply #3 on: June 08, 2024, 05:38:14 AM »
After 15 days of this experiment, I made some dimensional measurements.   
Concluded that of the 71 uA in meter, only about 3 uA is going through mercury and electrolyte -- the rest has another path inside the black box.   Turns out I'd reported the same numerical answers in that old 4hv post from 2010!  In which this specimen is called "the Russian meter".

The 2500-hour scale is 40 mm long, so the nominal speed of visible gap (and speed of drifting electrons in liquid Hg) is 0.016 mm per hour.   That's a little more than 1 cm per month.   The day-of-month wheel in a mechanical watch moves faster, but the high digits in a mechanical odometer move slower.

Each cubic mm of mercury represents 13.03 coulombs of what Faraday called "electricity" 200 years ago.   
So for nominal speed we need 57.9 amperes per square meter, 57.9 microamps per square millimeter.
Apparent diameter of capillary bore is 0.35 mm, for area of 0.096 mm^2, so it needs only 5.6 microamps, about 5% of what the instrument draws at 12 volts. (Measured resistance between terminals is 102.5 kΩ.)

Of course our view of capillary ID is magnified by the cylindrical glass OD.   Has anyone here ever run the optics numbers (lens formula) to get a factor for that?

[edit] Battery voltage is down to 8.79, meter voltage 7.18, after 15 days and 26 mAh.   Zinc anode metal in each battery cell is being depleted much faster than the mercury on left side of gap.
« Last Edit: June 08, 2024, 05:44:58 AM by klugesmith »

High Voltage Forum

Re: Coulometric hourmeters
« Reply #3 on: June 08, 2024, 05:38:14 AM »

 


* Recent Topics and Posts

post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
Mads Barnkob
Today at 07:43:37 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
petespaco
Today at 04:52:08 PM
post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
Today at 02:14:17 AM
post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 11:04:57 PM
post Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
June 12, 2024, 10:23:08 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 08:41:06 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 07:53:31 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
haversin
June 12, 2024, 06:57:13 PM
post UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 06:54:49 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
Mads Barnkob
June 12, 2024, 03:47:28 PM
post Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
vK
June 12, 2024, 03:42:18 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
davekni
June 12, 2024, 03:32:22 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 11, 2024, 11:05:49 PM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
June 11, 2024, 05:36:46 AM
post Re: Sling Psychrometer
[Laboratories, Equipment and Tools]
Twospoons
June 11, 2024, 12:29:31 AM
post Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 10, 2024, 11:05:55 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
June 10, 2024, 10:57:51 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 10, 2024, 08:08:04 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 10, 2024, 06:04:09 PM
post Sling Psychrometer
[Laboratories, Equipment and Tools]
klugesmith
June 10, 2024, 04:43:59 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 10, 2024, 03:35:28 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Jj
June 10, 2024, 01:36:41 PM
post Re: Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
Anders Mikkelsen
June 09, 2024, 05:44:29 PM
post Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
yourboi
June 09, 2024, 03:31:30 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
NyaaX_X
June 09, 2024, 01:34:49 PM
post Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
verliebt_in_neukölln17
June 09, 2024, 01:56:51 AM
post Re: Return of Electronics Flea Market in "Silicon Valley"
[Sell / Buy / Trade]
klugesmith
June 08, 2024, 06:06:25 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 08, 2024, 05:38:14 AM
post Interrupter for SSTC
[Beginners]
Simranjit
June 08, 2024, 12:47:47 AM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Michelle_
June 07, 2024, 03:59:57 PM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 06:42:26 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
MRMILSTAR
June 07, 2024, 05:08:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 03:16:31 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
klugesmith
June 06, 2024, 11:37:20 PM
post Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 11:20:23 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
June 06, 2024, 10:54:48 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 05:17:02 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 04:50:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 06, 2024, 04:00:52 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 01:43:41 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 11:11:17 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Michelle_
June 05, 2024, 10:18:57 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 10:13:03 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 05, 2024, 09:29:18 PM
post Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 08:46:53 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 05, 2024, 07:04:45 AM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 05, 2024, 04:58:35 AM
post Re: Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
klugesmith
June 05, 2024, 01:42:04 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 04, 2024, 10:31:58 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 04, 2024, 08:08:28 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 03, 2024, 11:13:26 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 10:35:57 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 05:51:05 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 03, 2024, 07:41:41 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 05:28:44 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 03, 2024, 05:02:19 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 03:47:33 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 02:23:58 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 01:25:24 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 03, 2024, 01:08:47 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 02, 2024, 10:29:02 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 10:02:45 PM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
davekni
June 02, 2024, 08:25:37 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 04:51:58 PM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Michelle_
June 02, 2024, 04:44:30 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
June 02, 2024, 03:25:11 PM
post APC Smart-UPS 1500VA Teardown
[Electronic Circuits]
Mads Barnkob
June 02, 2024, 01:36:11 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 02, 2024, 11:43:40 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 08:49:11 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 02, 2024, 08:36:07 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 12:41:50 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Benjamin Lockhart
June 01, 2024, 08:24:35 PM
post Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
Mads Barnkob
June 01, 2024, 08:22:28 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 01, 2024, 03:56:53 AM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
Terry
June 01, 2024, 12:03:50 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 31, 2024, 11:46:20 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 31, 2024, 06:13:59 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 31, 2024, 01:55:22 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
May 30, 2024, 11:57:49 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
May 30, 2024, 11:50:06 PM
post First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 30, 2024, 11:23:35 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
davekni
May 30, 2024, 10:43:06 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 30, 2024, 10:24:35 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 06:10:04 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 04:56:11 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 04:48:05 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 04:37:22 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
klugesmith
May 30, 2024, 04:16:31 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 03:34:10 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 02:53:50 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 12:44:47 PM
post SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 07:52:56 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 07:07:53 AM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
May 30, 2024, 07:04:40 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 05:16:50 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 05:08:17 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
davekni
May 30, 2024, 04:29:30 AM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 30, 2024, 03:52:36 AM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
davekni
May 30, 2024, 03:47:12 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Benjamin Lockhart
May 30, 2024, 03:41:34 AM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal