I set the output to 1Vp-p and then I found out, that I don't have any decent 50 Ohms BNC terminators.
And here just for fun I did a XY plot with the triangle function. Not really convinced about the linearity.
Settings: 500kHz, 0.8Vp-p, Ch2 +90°
No, the RTB 2004 has only 1MOhm||19pF, no 50Ohm termination.
And yes, I thought of the cabling and the wrong termination, too.
As soon as I have some proper T-adapters and BNC terminators I'll repeat this measuring again.
On the bench tonight: Back-to-school presents for the boy.
The Elegoo (yes, really ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks.
mnem
Start 'em young.
curve tracer voltage / current loop design. Currently uncompensated so this will no doubt oscillate like a wild monkey masturbating
sw1 sets voltage or current steps. sw2 sets step size.
Edit: looking at bias currents and stuff I’m going to have to add range switching for current sense for micro amp ranges. This gets really complicated really quickly. Need to build something that scales from 1uA to 10mA with better than 5% accuracy, universal stability under load level changes and a fair compliance range
I doubt a 741 can be used to measure high-side current; instrumentation amps are traditional, but ISTR there's an opamp with a ridiculously high input voltage spec (i.e. >>supply voltage) that can be used for this.
Will you need a negative supply?
If you need a higher voltage output, consider this circuit ...
FFI, see the current "High Voltage op amp" thread in s.e.d
It's fairly low voltage there as it's step generator only. All under 15V. I've got an INA series instrumentation amp somewhere with built in laser trimmed precision resistors which is getting substituted in when i find it. Bias current and offset are major issues rather than voltage on that bit. This has to source / sink a max of 100mA (for version 1 anyway) with about 5v of compliance or voltage steps up to 10V.
The high voltage supply is much simpler and is just a simple voltage controlled voltage regulator driven from 0-5v in and 0-200v out with a BU508A or similar on it. Only needs to source current fortunately so nothing fancy required!
Edit: place your bets. Broken or not broken? Hameg HM605:
Watch this , guy's a legend lol
On the bench tonight: Back-to-school presents for the boy.
The Elegoo (yes, really ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks.
mnem
Start 'em young.
Hahaha
Actually to be honest it was a guy who used to work for the local education authority around where I lived at the time. He was responsible for developing the science curriculum and took that opportunity to piss around with Lego, electronics and Acorn computers all day. He was mostly responsible for the BBC Micro and Lego in schools in the 1980s. My father was friends with him so I got to spend a day in his “lab” circa ‘82. About ten years after that he was made redundant when they centralised everything, his wife left him, moved to the US, bought a Trans AM and decided to retire by running a party boat full of floozies. Guy was a fucking legend. No idea if he’s still alive or not now.
On the bench tonight: Back-to-school presents for the boy.
The Elegoo (yes, really ) electro-bits kit was ~$15; it comes with a breadboard, PSU PCB for the breadboard, jumper kits and pretty much all the components needed for the first few chapters of the book. One of the first projects involves abusing a pot and deliberately toasting a LED... I like the way this guy thinks.
mnem
Start 'em young.
Lesson 1: No breadboard EVER looks that neat when you've finished wiring the circuit!
Hahaha
Actually to be honest it was a guy who used to work for the local education authority around where I lived at the time. He was responsible for developing the science curriculum and took that opportunity to piss around with Lego, electronics and Acorn computers all day. He was mostly responsible for the BBC Micro and Lego in schools in the 1980s. My father was friends with him so I got to spend a day in his “lab” circa ‘82. About ten years after that he was made redundant when they centralised everything, his wife left him, moved to the US, bought a Trans AM and decided to retire by running a party boat full of floozies. Guy was a fucking legend. No idea if he’s still alive or not now.
Lesson 1: No breadboard EVER looks that neat when you've finished wiring the circuit!
Mine always looks like a shrubbery. If it does work and is stable there, it'll work most everywhere.
So the Lady Copper's 11 year old Dell tower joined the great gig in the sky. Obviously it's my job to fix that. The only thing she ever uses a computer is to browse the internet. Or occasionally print something, from the internet. For that type of user Winblows seems like overkill. Decided that Linux would be the best solution for her. I have a Dell tower here with Mint on it but I'm not happy with that distro. It sucks. Slow to boot and overall just clunky. Also have a Toshiba laptop with Ubuntu 19. It boots fast and seems overall snappy. But it seems every time you boot it wants to load updates. But at least it's a pain free update process.
So....gonna take the Dell tower and wipe Mint and load Ubuntu. Show her how to use it and be a hero.
No, the RTB 2004 has only 1MOhm||19pF, no 50Ohm termination.
And yes, I thought of the cabling and the wrong termination, too.
As soon as I have some proper T-adapters and BNC terminators I'll repeat this measuring again.Ah, OK.
Later might come back with screenshots of how good...or not, a triangle is from a SDG6022X as maybe some data point to compare against.
Busy now.
So the Lady Copper's 11 year old Dell tower joined the great gig in the sky. Obviously it's my job to fix that. The only thing she ever uses a computer is to browse the internet. Or occasionally print something, from the internet. For that type of user Winblows seems like overkill. Decided that Linux would be the best solution for her. I have a Dell tower here with Mint on it but I'm not happy with that distro. It sucks. Slow to boot and overall just clunky. Also have a Toshiba laptop with Ubuntu 19. It boots fast and seems overall snappy. But it seems every time you boot it wants to load updates. But at least it's a pain free update process.
So....gonna take the Dell tower and wipe Mint and load Ubuntu. Show her how to use it and be a hero.
For updating my Ubuntu machines I'm running once a day under root:
apt-get update; apt-get -y dist-upgrade; apt-get -y autoremove
No "Klicki-Bunti" stuff
I noticed that Ubuntu 20 was just released. Are there any major changes from 19?