SMY-51 MOSFET Voltmeter

thingiverse

Update: Don't give up! We'll continue working here later. I will continue the work after finishing the other voltmeter project located at https://www.thingiverse.com/thing:3182399. A new blog post is being created about building a MOSFET voltmeter from the early 1970s. The central element of this project is the SMY-51 dual transistor from WF (Werk fuer Fernsehelektronik, Berlin-Schoeneweide, DDR). This project involves creating an up-and-coming MOSFET voltmeter using a P-channel MOSFET made in the former German Democratic Republic. To be accurate, it takes time. As much time as necessary! Give respect to people from the past; they deserve it. They did their work well, had fun, and even made love. I can tell you firsthand. No hateful speech or stupid stories about dumb communists, please. Sources are from early 70s. Bring your German language skills up a bit. Put some effort in. Do at least as much as I did learning alien languages. Fight the aliens who bring down every culture by infiltrating languages with nonsense. Speak your natural language first. Clean it up. Remove the garbage. But first things first! Read this: FET voltmeter using KP303 or BF245 or 2N3823 https://www.thingiverse.com/thing:3182399 The files: 1. Article as a pdf file with DIY instructions. 2. Article about calculating the voltmeter based on a differential amplifier. Files are too big to put here. Big pictures will be crippled when loading them up. Thanks, Autodesk! I have scanned in the pictures and cleaned them up. The pictures are taken from articles published in the 70s. Sources: "electronic" Heft 143, Hagen Jakubaschk, MOSFET Schaltungspraxis (Berlin, DDR 1976) "radio fernsehen elektronik" Heft2 1974 (Berlin, DDR) Files are loadable from external storage https://abload.de/image.php?img=voltmeter_smy_51_p208f0w.jpg https://abload.de/image.php?img=voltmeter_smy_51_p3ggidq.jpg https://abload.de/image.php?img=voltmeter_smy_51_p43yf9u.jpg https://abload.de/image.php?img=voltmeter_smy_51_p1gedsk.jpg https://abload.de/image.php?img=smyvoltmeterberechnunkxcrw.png https://abload.de/image.php?img=smyvoltmeterberechnunw5fuw.png Go retro making the PCB. Picture of my drawing tools I had started with ca. 1975 or even earlier. The "Karminrote Ausziehtusche" was resistant enough to etch copper away using Amonium Persulfat or similar. I'm not a friend of using the "braune Ätzplürre" called Fe3Cl ferrochlorid solution or so. You get the idea. I have some red Tusche leftover after 30 years in the bottle. It needed some drops of deionized water only. It works still. Don't expect this from modern technologies.