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On Fri, 03 Jan 2025 09:33:01 -0500, legg <legg@nospam.magma.ca> wrote:
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8 >>>>>package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
?
What's impractical about 4oz copper in a power circuit?
Are you saying it's not enough?
I'm saying that you can't put any other reasonable parts on the board.
4 Oz is fine for a demo board, but not so good for a board with 0402
parts and FPGAs and anything that does anything but measure current.
It would be interesting to get the eval board and actually push 50
amps through it.
I see a lot of data sheets with absurd power and current ratings, like
a dpak rated for hundreds of amps and watts, with tiny footnote
somewhere that cautions about package or lead limits. IR started the
trend of specifying chip therortetical limits that can't be approached
in real life, and then everybody had to tag along.
I'd say it was more than could be expected from a
simple demo board and is typical of higher current
layout in this neck of the woods, where power and
control circuits try not to share the same board or
board layer.
Exactly.
Also, using a part with a 50A full scale in a 25-30A
continuous rated circuit would be normal pactice,
where duty cycle, crest factor or pulse/surge are
anticipated under normal operating conditions.
There are 'better' SMD packages available, if that is your
only concern. You seem to have found some.
They could at least merged the high current pin pairs into big
paddles.
It's a nice part. We're using the 10 amp version at up to 7.5 amps.
The 50 amp version is silly.
On Fri, 03 Jan 2025 08:07:49 -0800, john larkin <JL@gct.com> wrote:
On Fri, 03 Jan 2025 09:33:01 -0500, legg <legg@nospam.magma.ca> wrote:
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8 >>>>>>package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
?
What's impractical about 4oz copper in a power circuit?
Are you saying it's not enough?
I'm saying that you can't put any other reasonable parts on the board.
4 Oz is fine for a demo board, but not so good for a board with 0402
parts and FPGAs and anything that does anything but measure current.
It would be interesting to get the eval board and actually push 50
amps through it.
I see a lot of data sheets with absurd power and current ratings, like
a dpak rated for hundreds of amps and watts, with tiny footnote
somewhere that cautions about package or lead limits. IR started the
trend of specifying chip therortetical limits that can't be approached
in real life, and then everybody had to tag along.
I'd say it was more than could be expected from a
simple demo board and is typical of higher current
layout in this neck of the woods, where power and
control circuits try not to share the same board or
board layer.
Exactly.
Also, using a part with a 50A full scale in a 25-30A
continuous rated circuit would be normal pactice,
where duty cycle, crest factor or pulse/surge are
anticipated under normal operating conditions.
There are 'better' SMD packages available, if that is your
only concern. You seem to have found some.
They could at least merged the high current pin pairs into big
paddles.
Ends up looking like an automotive fuse link.
It's a nice part. We're using the 10 amp version at up to 7.5 amps.
The 50 amp version is silly.
Well, when you actually get around to using it (probably in a
relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
On Sat, 04 Jan 2025 12:07:06 -0500, legg <legg@nospam.magma.ca> wrote:
On Fri, 03 Jan 2025 08:07:49 -0800, john larkin <JL@gct.com> wrote:
On Fri, 03 Jan 2025 09:33:01 -0500, legg <legg@nospam.magma.ca> wrote:
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote: >>>>>
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>>>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8 >>>>>>>package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
?
What's impractical about 4oz copper in a power circuit?
Are you saying it's not enough?
I'm saying that you can't put any other reasonable parts on the board.
4 Oz is fine for a demo board, but not so good for a board with 0402 >>>parts and FPGAs and anything that does anything but measure current.
It would be interesting to get the eval board and actually push 50
amps through it.
I see a lot of data sheets with absurd power and current ratings, like
a dpak rated for hundreds of amps and watts, with tiny footnote
somewhere that cautions about package or lead limits. IR started the >>>trend of specifying chip therortetical limits that can't be approached
in real life, and then everybody had to tag along.
I'd say it was more than could be expected from a
simple demo board and is typical of higher current
layout in this neck of the woods, where power and
control circuits try not to share the same board or
board layer.
Exactly.
Also, using a part with a 50A full scale in a 25-30A
continuous rated circuit would be normal pactice,
where duty cycle, crest factor or pulse/surge are
anticipated under normal operating conditions.
There are 'better' SMD packages available, if that is your
only concern. You seem to have found some.
They could at least merged the high current pin pairs into big
paddles.
Ends up looking like an automotive fuse link.
It's a nice part. We're using the 10 amp version at up to 7.5 amps.
The 50 amp version is silly.
Well, when you actually get around to using it (probably in a
relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs
Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same
rail for sensor Vcc and for the ADC reference. We'll autozero it every >powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some
charge when they sample, and that freaks out a lot of analog parts.
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
On Sat, 04 Jan 2025 09:37:24 -0800, john larkin <JL@gct.com> wrote:
On Sat, 04 Jan 2025 12:07:06 -0500, legg <legg@nospam.magma.ca> wrote:
On Fri, 03 Jan 2025 08:07:49 -0800, john larkin <JL@gct.com> wrote:
On Fri, 03 Jan 2025 09:33:01 -0500, legg <legg@nospam.magma.ca> wrote:
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote: >>>>>>
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>>>>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>>>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8 >>>>>>>>package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
?
What's impractical about 4oz copper in a power circuit?
Are you saying it's not enough?
I'm saying that you can't put any other reasonable parts on the board. >>>>4 Oz is fine for a demo board, but not so good for a board with 0402 >>>>parts and FPGAs and anything that does anything but measure current.
It would be interesting to get the eval board and actually push 50
amps through it.
I see a lot of data sheets with absurd power and current ratings, like >>>>a dpak rated for hundreds of amps and watts, with tiny footnote >>>>somewhere that cautions about package or lead limits. IR started the >>>>trend of specifying chip therortetical limits that can't be approached >>>>in real life, and then everybody had to tag along.
I'd say it was more than could be expected from a
simple demo board and is typical of higher current
layout in this neck of the woods, where power and
control circuits try not to share the same board or
board layer.
Exactly.
Also, using a part with a 50A full scale in a 25-30A
continuous rated circuit would be normal pactice,
where duty cycle, crest factor or pulse/surge are
anticipated under normal operating conditions.
There are 'better' SMD packages available, if that is your
only concern. You seem to have found some.
They could at least merged the high current pin pairs into big
paddles.
Ends up looking like an automotive fuse link.
It's a nice part. We're using the 10 amp version at up to 7.5 amps.
The 50 amp version is silly.
Well, when you actually get around to using it (probably in a
relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs
Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same
rail for sensor Vcc and for the ADC reference. We'll autozero it every >>powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some >>charge when they sample, and that freaks out a lot of analog parts.
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
So, the sensors are very remote.
RL
It's a nice part. We're using the 10 amp version at up to 7.5 amps. >>>>>The 50 amp version is silly.
Well, when you actually get around to using it (probably in a >>>>relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs
Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same >>>rail for sensor Vcc and for the ADC reference. We'll autozero it every >>>powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some >>>charge when they sample, and that freaks out a lot of analog parts.
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
So, the sensors are very remote.
RL
No, surface-mount, on the board. Close to the ADCs.
On Sun, 05 Jan 2025 13:53:36 -0800, john larkin <jl@glen--canyon.com>
wrote:
<snip>
Connector pins carry 8x 10A load current?It's a nice part. We're using the 10 amp version at up to 7.5 amps. >>>>>>The 50 amp version is silly.
Well, when you actually get around to using it (probably in a >>>>>relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs >>>>Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same >>>>rail for sensor Vcc and for the ADC reference. We'll autozero it every >>>>powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some >>>>charge when they sample, and that freaks out a lot of analog parts.
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
So, the sensors are very remote.
RL
No, surface-mount, on the board. Close to the ADCs.
RL
On Mon, 06 Jan 2025 08:30:42 -0500, legg <legg@nospam.magma.ca> wrote:
On Sun, 05 Jan 2025 13:53:36 -0800, john larkin <jl@glen--canyon.com>
wrote:
<snip>
Connector pins carry 8x 10A load current?It's a nice part. We're using the 10 amp version at up to 7.5 amps. >>>>>>> The 50 amp version is silly.
Well, when you actually get around to using it (probably in a
relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs
Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same >>>>> rail for sensor Vcc and for the ADC reference. We'll autozero it every >>>>> powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some >>>>> charge when they sample, and that freaks out a lot of analog parts.
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
So, the sensors are very remote.
RL
No, surface-mount, on the board. Close to the ADCs.
RL
I'm using 8 amp relays and rating things at 7.5 amps. We'll use
Phoenix connectors rated at 12 amps per pin.
The relays we have are DPDT, so we can put two contacts in series to
make a SPST closure and double the legal DC breaking voltage.
Here's what I have in mind:
https://www.dropbox.com/scl/fo/i7cpyb2t6zitll7ct2jok/ADuap85ok1QGUyRRAQzxk2o?rlkey=vdvw35y0ix9zbyt8mbok2t0hs&dl=0
My pcb design guy is underused lately so I figured I'd knock out a
couple of simple modules to keep us amused. But then feature-itus
kicked in. It could even be a polyphase power meter... maybe later.
The trick is to get the 2nd row of connectors onto the front panel.
I'm thinking a baby board and ten 2-56 spacers to support it and
bring the connections up.
On 1/6/25 16:54, john larkin wrote:
On Mon, 06 Jan 2025 08:30:42 -0500, legg <legg@nospam.magma.ca> wrote:
On Sun, 05 Jan 2025 13:53:36 -0800, john larkin <jl@glen--canyon.com>
wrote:
<snip>
Connector pins carry 8x 10A load current?It's a nice part. We're using the 10 amp version at up to 7.5 amps. >>>>>>>> The 50 amp version is silly.
Well, when you actually get around to using it (probably in a
relatively remote location) be sure to R/C the power and
data lines. R in series with source, C at receiving end.
RL
That Monolithic Hall sensor is analog output. Zero current outputs >>>>>> Vcc/2, and the sensitivity is ratiometric on Vcc. So one uses the same >>>>>> rail for sensor Vcc and for the ADC reference. We'll autozero it every >>>>>> powerup.
I'll RC filter a bit, right at the ADC input. Most ADCs kick out some >>>>>> charge when they sample, and that freaks out a lot of analog parts. >>>>>>
I'll have eight Hall sensors on a board, about like this one:
https://highlandtechnology.com/Product/P945
So, the sensors are very remote.
RL
No, surface-mount, on the board. Close to the ADCs.
RL
I'm using 8 amp relays and rating things at 7.5 amps. We'll use
Phoenix connectors rated at 12 amps per pin.
The relays we have are DPDT, so we can put two contacts in series to
make a SPST closure and double the legal DC breaking voltage.
Here's what I have in mind:
https://www.dropbox.com/scl/fo/i7cpyb2t6zitll7ct2jok/ADuap85ok1QGUyRRAQzxk2o?rlkey=vdvw35y0ix9zbyt8mbok2t0hs&dl=0
My pcb design guy is underused lately so I figured I'd knock out a
couple of simple modules to keep us amused. But then feature-itus
kicked in. It could even be a polyphase power meter... maybe later.
The trick is to get the 2nd row of connectors onto the front panel.
I'm thinking a baby board and ten 2-56 spacers to support it and
bring the connections up.
you can get dual row connectors, >https://nl.rs-online.com/web/p/pluggable-terminal-blocks/8817862
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that
stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
On a sunny day (Tue, 31 Dec 2024 15:58:07 -0800) it happened john larkin ><jl@glen--canyon.com> wrote in <nm09njhfcjh49jbof7qm3fl8pv321j34sk@4ax.com>:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that
stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
I use some of these:
https://www.lem.com/en/product-list/hx-10p
Maybe they have 50 amp versions too?
On Wed, 01 Jan 2025 08:11:06 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 31 Dec 2024 15:58:07 -0800) it happened john larkin >><jl@glen--canyon.com> wrote in <nm09njhfcjh49jbof7qm3fl8pv321j34sk@4ax.com>: >>
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
I use some of these:
https://www.lem.com/en/product-list/hx-10p
Maybe they have 50 amp versions too?
We have a LEM HMSR6-SMS instock... not sure why. There is a 30 amp
version. It's more accurate than the Monolithic part and has nice
chunky current leads, but it costs over 2x as much as the Mono part.
https://www.digikey.com/en/products/detail/lem-usa-inc/HMSR-6-SMS/12686318?s=N4IgTCBcDaIBIFkDKAlAbAWickBdAvkA
We can auto-zero the Monolithic part at powerup, which will help the
accuracy a bit.
I'm designing a plugin to our modular power system, just a board with
eight power relays. Then we figured, let's measure the voltage and
current of each relay too. Featuritus follows. Why not make it a
programmable circuit breaker? Why not a polyphase wattmeter? Somebody
please stop me.
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that
stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com>
wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that
stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
Looks like ACS7xx from Allegro.
Rl
On a sunny day (Wed, 01 Jan 2025 08:02:29 -0800) it happened john larkin ><JL@gct.com> wrote in <b0panjdbtuk2648jf9b2pe85sg65jqalsd@4ax.com>:
On Wed, 01 Jan 2025 08:11:06 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
On a sunny day (Tue, 31 Dec 2024 15:58:07 -0800) it happened john larkin >>><jl@glen--canyon.com> wrote in <nm09njhfcjh49jbof7qm3fl8pv321j34sk@4ax.com>: >>>
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
I use some of these:
https://www.lem.com/en/product-list/hx-10p
Maybe they have 50 amp versions too?
We have a LEM HMSR6-SMS instock... not sure why. There is a 30 amp
version. It's more accurate than the Monolithic part and has nice
chunky current leads, but it costs over 2x as much as the Mono part.
https://www.digikey.com/en/products/detail/lem-usa-inc/HMSR-6-SMS/12686318?s=N4IgTCBcDaIBIFkDKAlAbAWickBdAvkA
We can auto-zero the Monolithic part at powerup, which will help the >>accuracy a bit.
I'm designing a plugin to our modular power system, just a board with
eight power relays. Then we figured, let's measure the voltage and
current of each relay too. Featuritus follows. Why not make it a >>programmable circuit breaker? Why not a polyphase wattmeter? Somebody >>please stop me.
Long time ago I used an old tape recorder head as AC current sensor:
https://panteltje.nl/pub/play_back_head_current_sensor_img_1153.jpg
needs some amplification, rectifier.. so an opamp + diode.
But AC only.. but will work with more than 60 Hz, few dollars on ebay..
On Thu, 02 Jan 2025 13:01:42 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Wed, 01 Jan 2025 08:02:29 -0800) it happened john larkin >><JL@gct.com> wrote in <b0panjdbtuk2648jf9b2pe85sg65jqalsd@4ax.com>:
On Wed, 01 Jan 2025 08:11:06 GMT, Jan Panteltje <alien@comet.invalid> >>>wrote:
On a sunny day (Tue, 31 Dec 2024 15:58:07 -0800) it happened john larkin >>>><jl@glen--canyon.com> wrote in <nm09njhfcjh49jbof7qm3fl8pv321j34sk@4ax.com>:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8 >>>>>package. Or not for long.
Their demo board thermal design is kinda silly.
I use some of these:
https://www.lem.com/en/product-list/hx-10p
Maybe they have 50 amp versions too?
We have a LEM HMSR6-SMS instock... not sure why. There is a 30 amp >>>version. It's more accurate than the Monolithic part and has nice
chunky current leads, but it costs over 2x as much as the Mono part.
https://www.digikey.com/en/products/detail/lem-usa-inc/HMSR-6-SMS/12686318?s=N4IgTCBcDaIBIFkDKAlAbAWickBdAvkA
We can auto-zero the Monolithic part at powerup, which will help the >>>accuracy a bit.
I'm designing a plugin to our modular power system, just a board with >>>eight power relays. Then we figured, let's measure the voltage and >>>current of each relay too. Featuritus follows. Why not make it a >>>programmable circuit breaker? Why not a polyphase wattmeter? Somebody >>>please stop me.
Long time ago I used an old tape recorder head as AC current sensor:
https://panteltje.nl/pub/play_back_head_current_sensor_img_1153.jpg
needs some amplification, rectifier.. so an opamp + diode.
But AC only.. but will work with more than 60 Hz, few dollars on ebay..
For sensing AC current, one could use a milliohms-range 1206 resistor
and a signal transformer, a DRQ127 maybe. That all costs about a
dollar. All surface mount.
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com>
wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that
stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
They mostly wasted the bottom layer thermally.
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
They mostly wasted the bottom layer thermally.
The pour geometry crowds the heat into two corners so adds thermal >resistance.
The vias are too small and poorly located.
It's OK for maybe the 10 or 20 amp versions, but 50 will get nasty.
Looks like ACS7xx from Allegro.
This is nice:
https://www.digikey.com/en/products/detail/allegro-microsystems/ACS37010LLZATR-050B5/18734205?gclsrc=aw.ds&utm_adgroup=&gad_source=1&gclsrc=aw.ds
Good accuracy, chunky leads. But seems to only come in 30 and 50 amps.
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
?
What's impractical about 4oz copper in a power circuit?
Are you saying it's not enough?
I'd say it was more than could be expected from a
simple demo board and is typical of higher current
layout in this neck of the woods, where power and
control circuits try not to share the same board or
board layer.
Also, using a part with a 50A full scale in a 25-30A
continuous rated circuit would be normal pactice,
where duty cycle, crest factor or pulse/surge are
anticipated under normal operating conditions.
There are 'better' SMD packages available, if that is your
only concern. You seem to have found some.
RL
On Thu, 02 Jan 2025 08:09:16 -0800, john larkin <JL@gct.com> wrote:
On Thu, 02 Jan 2025 09:05:03 -0500, legg <legg@nospam.magma.ca> wrote:ACS711 has had commodity pricing for the last decade.
On Tue, 31 Dec 2024 15:58:07 -0800, john larkin <jl@glen--canyon.com> >>>wrote:
https://www.monolithicpower.com/en/mcs1802.html?srsltid=AfmBOoq2BNuYQ-Ef5ee9o7-gyHDqRkK_xS5TAKb-MgxtjZ6r71FItxXm
Really nice, as compared to a shunt and an isolated ADC and all that >>>>stuff. Reasonably accurate, especially above 20c.
But they can't be serious about pushing 50 amps through an SO8
package. Or not for long.
Their demo board thermal design is kinda silly.
Demo board makes sense to me. Simplest thermal conductivity
test.
They used 4 oz copper, hardly practical.
They mostly wasted the bottom layer thermally.
The pour geometry crowds the heat into two corners so adds thermal >>resistance.
The vias are too small and poorly located.
It's OK for maybe the 10 or 20 amp versions, but 50 will get nasty.
Looks like ACS7xx from Allegro.
This is nice:
https://www.digikey.com/en/products/detail/allegro-microsystems/ACS37010LLZATR-050B5/18734205?gclsrc=aw.ds&utm_adgroup=&gad_source=1&gclsrc=aw.ds
Good accuracy, chunky leads. But seems to only come in 30 and 50 amps.
RL
