I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
On Saturday, September 23, 2023 at 8:33:01 AM UTC-4, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?This would be fun, and quick to build:
https://www.homemade-circuits.com/high-voltage-meter-circuit-for-measuring-10kv/
The CA3140 is widely available and costs just a buck:
https://www.renesas.com/us/en/document/dst/ca3140-ca3140a-datasheet
You don't need to mess with those rheostats shown on the diagram, those are for calibrating that ancient 100uA FS meter.
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?Or maybe a 220k ohm resistor and a neon lamp?
On Saturday, September 23, 2023 at 11:37:49 AM UTC-7, Eddy Lee wrote:
On Saturday, September 23, 2023 at 10:49:20 AM UTC-7, whit3rd wrote:
On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
There's some crude multilamp variants that can tell 120VAC from 240 from 480...Did it light up well between 3V and 12V? I can tell when there is around 3V across the 6V light bulb.Will it work? Perhaps 22 or 33 ohms resistor?Or maybe a 220k ohm resistor and a neon lamp?
it gives enough info to rethink what meter (or meter setting) to use for the real
measurement thereafter. Neon doesn't glow at under 50V or so.
That relatively high strike voltage is how it can give a good glow indication off
high voltages without drawing much current, using no battery.
On Saturday, September 23, 2023 at 10:49:20 AM UTC-7, whit3rd wrote:
On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Did it light up well between 3V and 12V? I can tell when there is around 3V across the 6V light bulb.Will it work? Perhaps 22 or 33 ohms resistor?Or maybe a 220k ohm resistor and a neon lamp?
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused
muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms
resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
On Saturday, September 23, 2023 at 6:00:58 AM UTC-7, Fred Bloggs wrote:
On Saturday, September 23, 2023 at 8:33:01 AM UTC-4, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?This would be fun, and quick to build:
https://www.homemade-circuits.com/high-voltage-meter-circuit-for-measuring-10kv/
The CA3140 is widely available and costs just a buck:
https://www.renesas.com/us/en/document/dst/ca3140-ca3140a-datasheet
You don't need to mess with those rheostats shown on the diagram, those are for calibrating that ancient 100uA FS meter.This will measure high voltage, but my goal is really measuring low voltage (+/- 6V to 12V), with protection from high voltage. Blowing the light bulb is fine.
On Saturday, September 23, 2023 at 11:37:49 AM UTC-7, Eddy Lee wrote:
On Saturday, September 23, 2023 at 10:49:20 AM UTC-7, whit3rd wrote:
On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
There's some crude multilamp variants that can tell 120VAC from 240 from 480...Did it light up well between 3V and 12V? I can tell when there is around 3V across the 6V light bulb.Will it work? Perhaps 22 or 33 ohms resistor?Or maybe a 220k ohm resistor and a neon lamp?
it gives enough info to rethink what meter (or meter setting) to use for the real
measurement thereafter. Neon doesn't glow at under 50V or so.
That relatively high strike voltage is how it can give a good glow indication off
high voltages without drawing much current, using no battery.
On a sunny day (Sat, 23 Sep 2023 05:32:55 -0700 (PDT)) it happened Eddy Lee <eddy7...@gmail.com> wrote in
<4da5b75c-8e11-4689...@googlegroups.com>:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fused
muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms
resistor.
Will it work? Perhaps 22 or 33 ohms resistor?Specially for HV I bought a few dollar (5 USD or so) little analog multimeter after I blew up a digital one measuring a few kV in a PMT supply
https://panteltje.nl/pub/cheap_meter.jpg
It does not seem to care much about voltage overload...
Some multimeters, in particular EXTECH, have a Non-Contact Voltage (NCV) Detector in the form of an ionizing gas bulb that lights for VAC in the range 100-600 Volts AC.
These are available in the big box stores off the shelf / display hook.
https://www.flir.com/products/ex330/
On Sunday, September 24, 2023 at 5:40:16 AM UTC-7, Fred Bloggs wrote:
Some multimeters, in particular EXTECH, have a Non-Contact Voltage (NCV) Detector in the form of an ionizing gas bulb that lights for VAC in the range 100-600 Volts AC.
These are available in the big box stores off the shelf / display hook.
https://www.flir.com/products/ex330/My Greenlee GT-11 non contact detector is a capacitive pickup and lights an LED; it
only senses AC.
On Saturday, September 23, 2023 at 3:59:57 PM UTC-7, whit3rd wrote:
On Saturday, September 23, 2023 at 11:37:49 AM UTC-7, Eddy Lee wrote:
On Saturday, September 23, 2023 at 10:49:20 AM UTC-7, whit3rd wrote:There's some crude multilamp variants that can tell 120VAC from 240 from 480...
On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote: >> > > > I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.Did it light up well between 3V and 12V? I can tell when there is around 3V across the 6V light bulb.
Or maybe a 220k ohm resistor and a neon lamp?
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
it gives enough info to rethink what meter (or meter setting) to use for the real
measurement thereafter. Neon doesn't glow at under 50V or so.
That relatively high strike voltage is how it can give a good glow indication off
high voltages without drawing much current, using no battery.
But what I want is to tell the difference between two 392V sources, usually +/- 12V floating on top of 392V. However, sometimes it get mis-wired into sum, or 784V. In that case, it's OK to blow the bulb like a fuse.
On 2023-09-23, Eddy Lee <eddy7...@gmail.com> wrote:
On Saturday, September 23, 2023 at 3:59:57 PM UTC-7, whit3rd wrote:
On Saturday, September 23, 2023 at 11:37:49 AM UTC-7, Eddy Lee wrote: >> > On Saturday, September 23, 2023 at 10:49:20 AM UTC-7, whit3rd wrote: >> > > On Saturday, September 23, 2023 at 5:33:01 AM UTC-7, Eddy Lee wrote:
There's some crude multilamp variants that can tell 120VAC from 240 from 480...Did it light up well between 3V and 12V? I can tell when there is around 3V across the 6V light bulb.I often have to measure the difference of two 392V sources. Unfortunately, sometimes it becomes the sum, using one-time fused muti-meter.Or maybe a 220k ohm resistor and a neon lamp?
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
it gives enough info to rethink what meter (or meter setting) to use for the real
measurement thereafter. Neon doesn't glow at under 50V or so.
That relatively high strike voltage is how it can give a good glow indication off
high voltages without drawing much current, using no battery.
But what I want is to tell the difference between two 392V sources, usually +/- 12V floating on top of 392V. However, sometimes it get mis-wired into sum, or 784V. In that case, it's OK to blow the bulb like a fuse.a 6V lamp on 700V will probably blow like a 12V fuse does in the same circumstance (explosively), I suspect you would say not ok.
Just buy a 1000V auto-ranging multimeter, with whatever measurement catergory is suited to traction batteries (I'm guessing probably
Cat.IV )
--
Jasen.
🇺🇦 Слава Україні
On Saturday, September 23, 2023 at 10:55:34 PM UTC-7, Jan Panteltje=
wrote:
On a sunny day (Sat, 23 Sep 2023 05:32:55 -0700 (PDT)) it happened Eddy L= >ee
<eddy7...@gmail.com> wrote in
<4da5b75c-8e11-4689...@googlegroups.com>:
I often have to measure the difference of two 392V sources. Unfortunatel= >y, sometimes it become the sum, using a one-time fusedSpecially for HV I bought a few dollar (5 USD or so) little analog multim= >eter after I blew up a digital one measuring a few kV in a PMT supply
muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (= >for voltage), 6V 5W light bulb (for current) and 10 ohms
resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
https://panteltje.nl/pub/cheap_meter.jpg
It does not seem to care much about voltage overload...
I blew up a few of these, even for the older version with HV of 1000V. The=
newer one is 200V. Sometimes, the damage is not immediate. After a while=
, i got strange voltage readings.
https://www.harborfreight.com/7-function-digital-multimeter-63759.html
On Saturday, September 23, 2023 at 10:55:34 PM UTC-7, Jan Panteltje wrote:
On a sunny day (Sat, 23 Sep 2023 05:32:55 -0700 (PDT)) it happened Eddy Lee >> <eddy7...@gmail.com> wrote in
<4da5b75c-8e11-4689...@googlegroups.com>:
I often have to measure the difference of two 392V sources. Unfortunately, sometimes it become the sum, using a one-time fusedSpecially for HV I bought a few dollar (5 USD or so) little analog multimeter after I blew up a digital one measuring a few kV in a PMT supply
muti-meter.
I am thinking about using a rectifier diode (for direction) , 6V zener (for voltage), 6V 5W light bulb (for current) and 10 ohms
resistor.
Will it work? Perhaps 22 or 33 ohms resistor?
https://panteltje.nl/pub/cheap_meter.jpg
It does not seem to care much about voltage overload...
I blew up a few of these, even for the older version with HV of 1000V. The newer one is 200V. Sometimes, the damage is not immediate. After a while, i got strange voltage readings.
https://www.harborfreight.com/7-function-digital-multimeter-63759.html
Yea, I do not keep it connected for any length of time though...
And PMT circuits do not have a high current capability.
I blew up a nice digital one that was accidently on the Ohms range a few weeks ago
I expected the chip was dead, but investigation found just a 900 Ohm SMD resistor open circuit.
I replaced it by 680 and 220 Ohm in series... Reading is perfect again...
How I found out it should be 900 Ohm? divider circuit measured (with an other meter of course)
90 ? 9000 etc, so that in-between range had to be be 900.
On Sunday, September 24, 2023 at 4:17:02?PM UTC-4, whit3rd wrote:
On Sunday, September 24, 2023 at 5:40:16?AM UTC-7, Fred Bloggs wrote:
Some multimeters, in particular EXTECH, have a Non-Contact Voltage (NCV) Detector in the form of an ionizing gas bulb that lights for VAC in the range 100-600 Volts AC.My Greenlee GT-11 non contact detector is a capacitive pickup and lights an LED; it
These are available in the big box stores off the shelf / display hook.
https://www.flir.com/products/ex330/
only senses AC.
Greenlee? You don't mess around, that's one of the best out there.
On Sun, 24 Sep 2023 14:00:48 -0700 (PDT), Fred Bloggs <bloggs.fred...@gmail.com> wrote:
On Sunday, September 24, 2023 at 4:17:02?PM UTC-4, whit3rd wrote:
On Sunday, September 24, 2023 at 5:40:16?AM UTC-7, Fred Bloggs wrote:
Some multimeters, in particular EXTECH, have a Non-Contact Voltage (NCV) Detector in the form of an ionizing gas bulb that lights for VAC in the range 100-600 Volts AC.My Greenlee GT-11 non contact detector is a capacitive pickup and lights an LED; it
These are available in the big box stores off the shelf / display hook. >> >
https://www.flir.com/products/ex330/
only senses AC.
Greenlee? You don't mess around, that's one of the best out there.How about a neon lamp, a resistor and a capacitor ?
It will flash faster at higher voltage. Double the voltage should be easy-ish to distinguish from 1/2 that voltage.
boB
How about a neon lamp, a resistor and a capacitor ?
It will flash faster at higher voltage. Double the voltage should be easy-ish to distinguish from 1/2 that voltage.
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