Diy lab equipment for a student - Page 1
Forum section: electronics / projects

author: RawCode
author_rank: Regular Contributor
timestamp: October 16, 2017, 05:50:03 am
content: Hey folks. I want to build some lab equipment, like a variable power supply and a decent function generator.I've already have a decent variable power supply, 32V-0.8A, but I need something with dual supply. Is it possible to use a ATX power supply to build one, maybe bypassing the ov-uv protection? Can you help me?I want also build a decent function generator, for electronic application. I don't need a professional arbitrary function generator, but a decent one to study some common circuits. I found a PDF with an interesting function generator, it can do even sweeping mode(I don't understand what kind, linear o logarithmic) but it can output 3MHz in sine wave mode and only 300kHz in square mode. I don't know, is maybe a bit too little?You could say, why don't you use the equipment in your university (I'm a student). Well, because i don't live near my university, and I would like to test my homework at home in peace.What do you think?Inviato dal mio Nexus 5 utilizzando Tapatalk

author: jaycee
author_rank: Regular Contributor
timestamp: October 16, 2017, 11:06:00 am
content: ATX power supplies are only really good at providing their fixed voltages. So if you need a high current source of +3.3v, +5v, +12v etc they are OK for that, but useless as an adjustable source. Also they have no adjustable current limiting, so if you make a short things are going to smoke pretty quickly.The DPS3003 module Dave just reviewed is pretty hard to compete with on price, and is certainly better than nothing if you accept it's limitations. The KORAD KA3005P power supply is also very good for the price you can get them (ive seen them for £60 - can't even buy the parts to build a similar supply for that!)For function generators, there are kits based on the old MAX038 or XR2206 which are a fairly good start. If you are comfortable with programming an Arduino or PIC/AVR, chips like the AD9833 are a good way of getting a DDS based function generator. There's also kits on eBay using those chips.Alternatively, get really friendly with your Uni's lab technical staff. You never know what they might be hoarding or throwing away

author: ebclr
author_rank: Super Contributor
timestamp: October 16, 2017, 12:21:00 pm
content: A nice kit for student function generatorhttps://pt.aliexpress.com/item/1-Set-ICL8038-Monolithic-Function-Signal-Generator-Module-DIY-Kit-Sine-Square-Triangle/32740472514.html?spm=a2g03.search0104.3.2.bSqWmJ&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10068_10344_10345_10342_10343_10340_10341_10307_10060_10155_10154_10056_10055_10054_10538_10537_10059_10536_10535_10534_10533_100031_10099_10338_10103_10102_10052_10053_10142_10107_10050_10051_10173_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10312_10313_10314_10078_10079_10073,searchweb201603_2,ppcSwitch_5&btsid=8153a13a-c7bd-471c-bf2e-548a64575f65&algo_expid=94636bc8-2128-49f3-bd9d-adc9b90fdde2-0&algo_pvid=94636bc8-2128-49f3-bd9d-adc9b90fdde2A second optionhttps://pt.aliexpress.com/item/XR2206-Function-Signal-Generator-DIY-Kit-Sine-Triangle-Square-Output-1HZ-1MHZ/32784587881.html?spm=a2g03.search0104.3.2.qjmB8P&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10068_10344_10345_10342_10343_10340_10341_10307_10060_10155_10154_10056_10055_10054_10538_10537_10059_10536_10535_10534_10533_100031_10099_10338_10103_10102_10052_10053_10142_10107_10050_10051_10173_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10312_10313_10314_10078_10079_10073-10102,searchweb201603_2,ppcSwitch_5&btsid=f7a17eb7-715d-4041-868f-874640eba011&algo_expid=2c794955-26b0-40c2-8e61-f9cc68960918-0&algo_pvid=2c794955-26b0-40c2-8e61-f9cc68960918

author: Kleinstein
author_rank: Super Contributor
timestamp: October 16, 2017, 05:22:28 pm
content: You can get low cost versions from China for a surprisingly low price now. For the supply you won't even get the parts for that price. There are also rather low cost DDS based generators (e.g. in the $50-100 range). Even the simple old style Fgens can be good enough for quite a lot of things.The main reason for building it yourself would be that you may learn how it works. So more for educational purpose than for the money.An ATX supply is not a good starting point for a lab supply. A laptop supply would be a better choice. Another old part that might be used would be an old Hifi amplifier. In the best case one could reuse the case, transformer, rectifier and heat sink, maybe even the power transistors.