#bjt — Public Fediverse posts

Electronics idea.

There are opamps with bipolar junction transistors (BJT) in the input stage.

There are others with junction field-effect transistors (JFET) in the input stage.

There are yet others with metal-oxide semiconductor field effect transistors (MOSFET) [1] in the input stage.

Idea: find an application for the bizarre possibility of an opamp with insulated-gate bipolar transistors (IGBT) in the input stage. This is more stunt-designing than anything practical.

[1] IIUC, "CMOS" opamps are really just MOSFET-input opamps. I'm not sure why the process technology name is more commonly used rather than the device type as is universally used for BJT and JFET input opamps.

#OpAmp #electronics #OperationalAmplifier #JFET #BJT #MOSFET #IGBT #CMOS #stunt

2025 Component Abuse Challenge: Reverse Biasing an NPN BJT - For the Component Abuse Challenge our hacker [Tim Williams] observes that N-P-N re... - https://hackaday.com/2025/11/06/2025-component-abuse-challenge-reverse-biasing-an-npn-bjt/ #reversebias #science #bjt #npn

2025 Component Abuse Challenge: Reverse Biasing an NPN BJT https://hackaday.com/2025/11/06/2025-component-abuse-challenge-reverse-biasing-an-npn-bjt/ #reversebias #Science #bjt #npn

I refuse to be on SVIP tier on wetv (just VIP 💀) so I already caught the first two eps of the new season… And this is turning into such a temptation because the cast and concept has really gelled this season but noooo I must keep this as my weekly feel-good tv. Just watching the new extended trailer (without subtitles even) is making me crack up.

If you don't know the show, the whole premise of Natural High is the cast visiting a few locations (so far in China) and be exposed to the local culture so it's part travelogue and foodie tour but also a demented gathering of funny people which is inevitable when you keep making them play variations of the Werewolf game and also parlor games. Wetv also has a habit of uploading their variety shows on YouTube, and subtitles are decent enough.

https://www.youtube.com/watch?v=HpYUXFrCepk

Measuring the characteristics of some cheap J113 / 2SJ113 n-channel JFETs I bought, so I can match them / divvy them into bins.

Put #15 of 20 into the JFET test circuit, and the power supply's current limiter kicks in ... whoops. Did I have it turned around so I swapped the terminals? Nope...

Take a peek at it. Slightly different marking. Still "J113", but the factory/date code is different. Put it in the component tester... it's a PNP BJT transistor, not a JFET at all, and with a pinout completely unsuitable for the JFET test circuit. If it had been in for more than a second, it probably would have let the Magic Smoke out.

Oh, #AliExpress sellers, where would #hobbyist #electronics people be without you? Somewhere with less excitement in their lives, I guess.

#MagicSmoke #Chinesium #fake #remarked #component #transistor #JFET #BJT #J113 #hobby

New Bismuth Transistor Runs 40% Faster and Uses 10% Less Power https://hackaday.com/2025/05/16/new-bismuth-transistor-runs-40-faster-and-uses-10-less-power/ #bismuthseleniteoxide #bismuthoxyselenide #semiconductor #transistor #SOIMOSFET #hardware #Science #bismuth #finfet #GAAFET #mosfet #bjt

New Bismuth Transistor Runs 40% Faster and Uses 10% Less Power - Recently in material science news from China we hear that [Hailin Peng] and his te... - https://hackaday.com/2025/05/16/new-bismuth-transistor-runs-40-faster-and-uses-10-less-power/ #bismuthseleniteoxide #bismuthoxyselenide #semiconductor #transistor #soimosfet #hardware #science #bismuth #finfet #gaafet #mosfet #bjt

Erasing EEPROMs isn’t Always as Easy as it Seems - When is 14 volts not actually 14 volts? Given [Anders Nielsen]’s recent struggles ... - https://hackaday.com/2024/01/20/erasing-eeproms-isnt-always-as-easy-as-it-seems/ #retrocomputing #switching #27c512 #2n3904 #2n3906 #eeprom #parts #retro #bjt

The Geometry of Transistors - Building things in a lab is easy, at least when compared to scaling up for mass pr... - https://hackaday.com/2023/12/13/the-geometry-of-transistors/ #bipolarjunctiontransistor #semiconductor #transistor #science #shape #bjt #npn

Sounding the Humble LED - Here at Hackaday we’re no strangers to the colorful glow of LEDs. But what if there was more to appr... - https://hackaday.com/2021/02/27/sounding-the-humble-led/ #currentamplifier #candleflicker #flickeringled #synthesizer #hardware #art #bjt #led

The Descendants of Ancient Computers - Building computers from discrete components is a fairly common hobby project, but it used to be th... more: https://hackaday.com/2020/05/31/the-descendants-of-ancient-computers/ #bipolarjunctiontransistor #computerhacks #supercomputer #transistor #frequency #switching #computer #discrete #parts #retro #cray #bjt