{"id":497,"date":"2022-12-05T21:54:30","date_gmt":"2022-12-05T20:54:30","guid":{"rendered":"https:\/\/labparvum.com\/?p=497"},"modified":"2025-05-26T19:27:43","modified_gmt":"2025-05-26T19:27:43","slug":"power-monitor-pernosco-navitas","status":"publish","type":"post","link":"https:\/\/labparvum.com\/index.php\/2022\/12\/05\/power-monitor-pernosco-navitas\/","title":{"rendered":"Power monitor &#8211; pernosco navitas"},"content":{"rendered":"\n<p>I wanted a power monitor with high accuracy and fast update speed, but could not find a solution that I liked so I set out to design my own.<br>Using the ATM90E32 I made a 3-channel voltage\/current and power sensor with high accuracy and very fast update speed.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" data-id=\"504\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-1024x768.jpg\" alt=\"\" class=\"wp-image-504\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-1024x768.jpg 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-300x225.jpg 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-768x576.jpg 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-1536x1152.jpg 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202301041115161-scaled-1-2048x1536.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" data-id=\"505\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-1024x768.jpg\" alt=\"\" class=\"wp-image-505\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-1024x768.jpg 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-300x225.jpg 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-768x576.jpg 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-1536x1152.jpg 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506591-scaled-1-2048x1536.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" data-id=\"506\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-1024x768.jpg\" alt=\"\" class=\"wp-image-506\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-1024x768.jpg 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-300x225.jpg 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-768x576.jpg 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-1536x1152.jpg 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/IMG202306121506441-scaled-1-2048x1536.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n<\/figure>\n\n\n\n\n\n<p>Specifications:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Input voltage: 90VAC &#8211; 250VAC<\/li>\n\n\n\n<li>Power consumtion: &lt;1W<\/li>\n\n\n\n<li>voltage measurement accuracy: 0.1%<\/li>\n\n\n\n<li>Measuring current range: 5mA -&gt; 16A<\/li>\n\n\n\n<li>Current measurement accuracy: 0.5% +-5mA (pf=1)<\/li>\n\n\n\n<li>update speed 0.1s &#8211; 0.2s (esphome bottleneck)<br><\/li>\n<\/ul>\n\n\n\n<p>Some improvements that might be implemented in a new revision:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Better accuracy when measuring a load with a bad power factor and high frequency noise.<br>Currently capacitive loads have a current measuring offset causing inaccuracies.<br>This is most noticeable when only a capacitor is attached, this will cause the meter to measure a slight negative power value.<br>This will most likely be solved by using shunts instead of current coils.<\/li>\n\n\n\n<li>Smaller footprint.<br>using different components and changing the layout could significantly reduce the overall board size while keeping the same specs. The board might also need to be changed to 4 layers or use 2oz copper to achieve this.<\/li>\n\n\n\n<li>better flexibility.<br>with jumpers and different layout it should be possible to give a choice of how to measure power. this could also enable the possibility to measure 3phase power.<\/li>\n\n\n\n<li>add new functionality.<br>The ability to use a small screen and use an esp32 instead of an esp8266 can be easily implemented in a new revision.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Design<\/h2>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-a6139faf-7541-441e-825d-64f65ffec12e\" href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/Pernosco-Navitas-V1.0.7z\">Pernosco-Navitas-V1.0<\/a><a href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/Pernosco-Navitas-V1.0.7z\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-a6139faf-7541-441e-825d-64f65ffec12e\">All Altium design files<\/a><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Power supply<\/h3>\n\n\n\n<p>The power from the board is supplied by a very small 230V-&gt;3.3V SMPS module.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"361\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3-1024x361.png\" alt=\"\" class=\"wp-image-514\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3-1024x361.png 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3-300x106.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3-768x271.png 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3-1536x542.png 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-3.png 1877w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>A second Isolated 3.3V power rail is created with a special isolated DC-DC converter.<br>The secondary 3.3V rail is referenced to one side of the 230VAC.<br>This is done to achieve 2 goals.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Isolate the esp8266\/esp32 from 230VAC.<br>This allows the USB connector to still be used when the device is connected to 230V<br>And when an esp8266\/esp32 is used with an external antenna this antenna would also be live with mains voltage if not isolated. this could cause mayor safety concerns.<\/li>\n\n\n\n<li>Keep power consumption low.<br>If the power measuring IC would also be Isolated from the mains voltage I would need to use a small transformer to step down the voltage and isolate it. Even the smallest low power 230VAC trafo&#8217;s had a standby power consumption of around 1W, this transformer would consume more power than the whole rest of the board just to step down and isolate the voltage. That&#8217;s why the power measuring IC GND is referenced to the 230VAC. Stepping the voltage down for the measurment is done with a simple voltage divider.<\/li>\n<\/ul>\n\n\n\n<p>The isolated DC-DC converter is also specially chosen to handle 320V peak continuously.<br>Most isolated DC-DC converters are only rated to withstand 1000V for a minute but will break down over time if a large voltage difference is present<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"330\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6-1024x330.png\" alt=\"\" class=\"wp-image-517\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6-1024x330.png 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6-300x97.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6-768x247.png 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6-1536x495.png 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-6.png 1590w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Isolated DC-DC safety approval for continuous high voltage across power rails<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"435\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4-1024x435.png\" alt=\"\" class=\"wp-image-515\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4-1024x435.png 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4-300x127.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4-768x326.png 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4-1536x652.png 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-4.png 1699w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Isolated DC-DC circuit<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"406\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5-1024x406.png\" alt=\"\" class=\"wp-image-516\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5-1024x406.png 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5-300x119.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5-768x305.png 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5-1536x609.png 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-5.png 1861w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Voltage divider to measure 230VAC input side<\/figcaption><\/figure>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-90ea8108-7bb8-43fc-a3f5-32af2e552b8b\" href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/kdc-nxj1.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">kdc-nxj1<\/a><a href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/kdc-nxj1.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-90ea8108-7bb8-43fc-a3f5-32af2e552b8b\">Download<\/a><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Digital isolation<\/h3>\n\n\n\n<p>The power supply isolation also posed a problem for digital communication.<br>For this, I used a quad-channel capacitive isolator, which allows high-speed communication with a high degree of isolation.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"885\" height=\"249\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-7.png\" alt=\"\" class=\"wp-image-519\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-7.png 885w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-7-300x84.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-7-768x216.png 768w\" sizes=\"auto, (max-width: 885px) 100vw, 885px\" \/><figcaption class=\"wp-element-caption\">Digital isolator rated lifetime at continuous working voltage.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1016\" height=\"968\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-9.png\" alt=\"\" class=\"wp-image-521\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-9.png 1016w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-9-300x286.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-9-768x732.png 768w\" sizes=\"auto, (max-width: 1016px) 100vw, 1016px\" \/><figcaption class=\"wp-element-caption\">Digital isolator circuit<\/figcaption><\/figure>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-75176ca7-e6a8-452e-bbc5-c2e1fbc08438\" href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/ADuM7440_7441_7442.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">ADuM7440_7441_7442<\/a><a href=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/ADuM7440_7441_7442.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-75176ca7-e6a8-452e-bbc5-c2e1fbc08438\">Download<\/a><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Current measurement<\/h3>\n\n\n\n<p>The current is measured using a current transformer on each channel.<br>The input stage consists of a dual stage low pass filter, Zener diodes to clamp current spikes, and a resistor voltage divider to set the max measured current to 21.6Arms.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"239\" src=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-1024x239.png\" alt=\"\" class=\"wp-image-526\" srcset=\"https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-1024x239.png 1024w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-300x70.png 300w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-768x179.png 768w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-1536x358.png 1536w, https:\/\/labparvum.com\/wp-content\/uploads\/2023\/06\/image-10-2048x477.png 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>I wanted a power monitor with high accuracy and fast update speed, but could not find a solution that I liked so I set out to design my own.Using the ATM90E32 I made a 3-channel voltage\/current and power sensor with high accuracy and very fast update speed. Specifications: Some improvements<\/p>\n<p><a href=\"https:\/\/labparvum.com\/index.php\/2022\/12\/05\/power-monitor-pernosco-navitas\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\">Power monitor &#8211; pernosco navitas<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":504,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-497","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electronics"],"_links":{"self":[{"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/posts\/497","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/comments?post=497"}],"version-history":[{"count":1,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/posts\/497\/revisions"}],"predecessor-version":[{"id":786,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/posts\/497\/revisions\/786"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/media\/504"}],"wp:attachment":[{"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/media?parent=497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/categories?post=497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/labparvum.com\/index.php\/wp-json\/wp\/v2\/tags?post=497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}