{"id":1777,"date":"2018-02-19T00:28:07","date_gmt":"2018-02-19T00:28:07","guid":{"rendered":"http:\/\/www.blog.exrockets.com\/blog\/?p=1777"},"modified":"2019-04-08T08:19:15","modified_gmt":"2019-04-08T08:19:15","slug":"rocket-thrust-stand-small-daq-system-2","status":"publish","type":"post","link":"http:\/\/www.blog.exrockets.com\/blog\/rocket-thrust-stand-small-daq-system-2\/","title":{"rendered":"ROCKET THRUST STAND SMALL DAQ SYSTEM 2"},"content":{"rendered":"<p>his DAQ schematic is a new improved version of my old <a href=\"http:\/\/www.blog.exrockets.com\/blog\/rocket-thrust-stand-small-daq-system\/\">ROCKET THRUST STAND SMALL DAQ SYSTEM<\/a>. The small changes that I made are as follow:<\/p>\n<ul>\n<li>A small PPTC fuse was placed at the input to limit the current drawn from the battery in case of short circuit<\/li>\n<li>The 5v excitation voltage is buffered now through an OPAMP in order to supply higher current if needed<\/li>\n<li>The output of the instrumental amplifier was shifted to 1.2 volts for more accurate measurements and calibration<\/li>\n<\/ul>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1781\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg\" alt=\"\" width=\"1800\" height=\"993\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg 1800w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-300x166.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-768x424.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-1024x565.jpg 1024w\" sizes=\"auto, (max-width: 1800px) 100vw, 1800px\" \/><\/a><\/p>\n<p>The rest of the DAQ system remains the same:<\/p>\n<p>\u2013 This DAQ system can be powered from 8.5 volts to 12 volt DC or AC sources, where the polarity of the connectors is not important. If the supply voltage drops below 8.5v the system still will be working but the readings will no longer be correct<br \/>\n*Please note that some rechargeable \u201c9 volt\u201d batteries have actual nominal voltage of less than 8.5 volt<br \/>\n\u2013 The total consumption while recording the test is about 50 mA<br \/>\n\u2013 It can record up to 3 tests before you will need to erase the memory<br \/>\n\u2013 The total test time allowed per bank of memory is approximately 16 seconds<br \/>\n\u2013 Can work in autonomous mode where the data is stored in memory or in real-time mode by sending the data directly to the PC<br \/>\n\u2013 In stand-alone mode the time stamp is 0.002 seconds<br \/>\n\u2013 In real-time mode the time stamp is 0.01 seconds<br \/>\n\u2013 Circular buffer that keeps data for 1\/4 second before the detected start<br \/>\n\u2013 Automatically detects the start<br \/>\n\u2013 Low-voltage detection<br \/>\n\u2013 There are two ports \u2013 PORT A and PORT B<br \/>\n\u2013 Port A is intended for load cells (this is normally where the thrust stand is connected)<br \/>\n\u2013 Port B can be used to connect another source to be digitized where the input voltage shouldn\u2019t exceed 5 volts (although there is a clamping diode that should prevent damage to the system if this voltage is surpassed)<br \/>\n\u2013 JP1 (the one next to the USB port) will enable\/disable the buzzer<br \/>\n\u2013 JP3 to JP6 will select the system gain \u2013 100, 200, 500 and 1000 times. This is to say that the signal from the load cell will be amplified that many times<br \/>\n\u2013 The small button on the bottom side is intended to provide the possibility to format the device even when it is not connected to a computer. To prevent accidental erasure there is a procedure to follow before the memory can be erased<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1780\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH.png\" alt=\"\" width=\"4200\" height=\"2784\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH.png 4200w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH-300x199.png 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH-768x509.png 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SCH-1024x679.png 1024w\" sizes=\"auto, (max-width: 4200px) 100vw, 4200px\" \/><\/a><\/p>\n<p>LOW-VOLTAGE DETECTION:<\/p>\n<p>This reference diode is configured to work in the range from 8.5 to 12v with a standard load cell load of more than 300 Ohm. The LDO regulator works down to 6v while keeping 5 volt output. However if the power supply drops below 8.5v the output from the reference diode (under load) will be lower than 5 volts.<\/p>\n<p>The system will compare the voltage output from the 5 volt reference diode and the LDO regulator. If there is a difference of more than 50 mV from both outputs the system will stop and give a continuous audio signal meaning that the battery output is less than 8.5 volts.<\/p>\n<p>NEW PCB<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1782\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT.jpg\" alt=\"\" width=\"289\" height=\"160\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT.jpg 1800w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT-300x166.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT-768x424.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT-1024x565.jpg 1024w\" sizes=\"auto, (max-width: 289px) 100vw, 289px\" \/>\u00a0<\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1781\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg\" alt=\"\" width=\"288\" height=\"159\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP.jpg 1800w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-300x166.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-768x424.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP-1024x565.jpg 1024w\" sizes=\"auto, (max-width: 288px) 100vw, 288px\" \/><\/a><\/p>\n<p>OLD PCB<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1785\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old.jpg\" alt=\"\" width=\"283\" height=\"155\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old.jpg 1736w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old-300x165.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old-768x422.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/BOT_old-1024x562.jpg 1024w\" sizes=\"auto, (max-width: 283px) 100vw, 283px\" \/>\u00a0<\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1786\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old.jpg\" alt=\"\" width=\"291\" height=\"156\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old.jpg 1590w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old-300x161.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old-768x411.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/TOP_old-1024x548.jpg 1024w\" sizes=\"auto, (max-width: 291px) 100vw, 291px\" \/><\/a><\/p>\n<p>The PCB size and the main components remained at the same place, so the case from the old DAQ described here (<a href=\"http:\/\/www.blog.exrockets.com\/blog\/rocket-thrust-stand-small-daq-system\/\">ROCKET THRUST STAND SMALL DAQ SYSTEM<\/a>) can be used with this DAQ as well.<\/p>\n<p>The firmware was modified to account for the changed ports to which the LEDs are connected, but the logical flowchart remains unchanged.<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1788\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW.png\" alt=\"\" width=\"1533\" height=\"2405\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW.png 1533w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW-191x300.png 191w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW-768x1205.png 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/FLOW_CHART_NEW-653x1024.png 653w\" sizes=\"auto, (max-width: 1533px) 100vw, 1533px\" \/><\/a>I used the opportunity to fix some bugs in the software and also I made a nice addition to the functionality by adding a Furrier analysis for stand data. \u00a0The DFT was done by implementing \u00a0the <a href=\"https:\/\/www.codeproject.com\/Articles\/1107480\/DSPLib-FFT-DFT-Fourier-Transform-Library-for-NET\">DSPLib library<\/a>.<\/p>\n<p>You can see in the next two screenshots the frequency spectrum of a real motor test from <a href=\"http:\/\/kia-soft.narod.ru\/index.htm\">RocKI<\/a>.<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1801\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP.jpg\" alt=\"\" width=\"1370\" height=\"820\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP.jpg 1370w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP-300x180.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP-768x460.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSP-1024x613.jpg 1024w\" sizes=\"auto, (max-width: 1370px) 100vw, 1370px\" \/><\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1802\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT.jpg\" alt=\"\" width=\"1385\" height=\"848\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT.jpg 1385w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT-300x184.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT-768x470.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/NSPDFT-1024x627.jpg 1024w\" sizes=\"auto, (max-width: 1385px) 100vw, 1385px\" \/><\/a><\/p>\n<p>My initial intention was to use the thrust stand with calibration weights of at least 1 kg which allows you to use 1kg load cells. But I have been already asked several times if the thrust stand DAQ can be used for micro motors where thrust in the gram-range will be measured.<\/p>\n<p>To do that you will have to use a load cell, rated less than 1 kg (for example 100gr, 200gr or 500gr load cells). However in this case you will need calibration weights of less than 1 kg. To implement this function I had to make a minor modification in the firmware as well as in the software application. Now you will have the option of choosing what is the measurement unit used for calibration i.e. kilograms or grams and the calibration weight range is either from 1gr to 255gr or 1kg to 255kg.<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/LC2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1797\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/LC2.jpg\" alt=\"\" width=\"1024\" height=\"543\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/LC2.jpg 1024w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/LC2-300x159.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/LC2-768x407.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1789\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1.jpg\" alt=\"\" width=\"1200\" height=\"484\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1.jpg 1200w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1-300x121.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1-768x310.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M1-1024x413.jpg 1024w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1790\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3.jpg\" alt=\"\" width=\"1200\" height=\"489\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3.jpg 1200w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3-300x122.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3-768x313.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M3-1024x417.jpg 1024w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1791\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4.jpg\" alt=\"\" width=\"1200\" height=\"404\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4.jpg 1200w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4-300x101.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4-768x259.jpg 768w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/M4-1024x345.jpg 1024w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/STS_2_RS274X-CADCAM.zip\">SMALL_THRUST_STAND_2_CADCAM_PCB_FILES<\/a><br \/>\n<a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SMALL_THRUST_STAND_2018_HID.zip\">SMALL_THRUST_STAND_2_HID_FIRMWARE<\/a><br \/>\n<a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2018\/02\/SMALL_THRUST_STAND_2018_APPLICATION_KG_GR_1.06.zip\">SMALL_THRUST_STAND_2_APPLICATION_1.06<\/a><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>his DAQ schematic is a new improved version of my old ROCKET THRUST STAND SMALL DAQ SYSTEM. The small changes that I made are as follow: A small PPTC fuse was placed at the input to limit the current drawn from the battery in case of short circuit The 5v excitation voltage is buffered now [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"gallery","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-1777","post","type-post","status-publish","format-gallery","hentry","category-electronics","post_format-post-format-gallery"],"_links":{"self":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1777","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/comments?post=1777"}],"version-history":[{"count":10,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1777\/revisions"}],"predecessor-version":[{"id":2336,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1777\/revisions\/2336"}],"wp:attachment":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/media?parent=1777"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/categories?post=1777"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/tags?post=1777"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}