If you're interested in a relatively inexpensive oscilloscope to play around with, check out the Rigol 1054Z (or 1074Z Plus if you want MSO capabilities). It's four channels and has more than enough features for playing around with, especially for the price. Using the Riglol website, you can unlock all software options on it, including increasing the bandwidth to 100mHz and the memory to 24MP.
It was the first 'real' scope I bought and I still use it a fair amount despite having upgraded to a Rohde and Schwarz MSO model. I've been amazed how much I use an oscilloscope after getting one, from measuring ripple on power supplies to diagnosing serial communication issues.
> Using the Riglol website, you can unlock all software options on it, including increasing the bandwidth to 100mHz and the memory to 24MP.
It's interesting how Rigol did the locking of those extra features. The unlock key for a feature set for your scope has to be signed by a Rigol private key using an elliptic curve signature system.
But they are only using a 56 bit private key. That was quickly brute forced, and key generators proliferated.
They used a good library for the cryptography stuff, and except for the short key seem to have used it well and knew what they were doing. This suggests that the choice of a weak key was deliberate.
Each family of scopes has its own private key. As few families came out with new private keys, Rigol continued to use 56 bits. When major firmware upgrades came out in existing families, where they could have easily changed to a longer private key, they kept the same 56 bit that was now widely circulated on the net.
It seems pretty clear that they are not interested in stopping people from free unlocking.
It seems like a decent price discrimination strategy to me. They make advanced capabilities more price-accessible to particularly interested hobbyists and more popular among that market, and probably aren't losing much revenue from corporate and academic institution sales.
Thanks for the recommendations! I have a DSLabs DScope (100 MHz, 2-channel FPGA scope) and while it’s handy I’d prefer to have a proper hardware scope someday. Rigol’s scopes look like they nicely fit in between the basic DSO/FPGA stuff and the “proper” 4-5 digit priced test bench gear.
Any recommendations for learning resources that could help with understanding DC power supply analysis for non-EE types? While refurbishing laptops and working with microcontrollers I’ve run into some odd things where ruling out transient power supply issues would probably be helpful.
The low end Rigols make good entry-level scopes, and have a surprising amount of capability for the price.
As for learning resources, I came across a decent article on the subject when I was starting out (1), and most of the oscilloscope manufacturers have whitepapers on SMPS diagnostics, the Tektronics one I read a while back (2) gave a good overview. A lot of the whitepapers have a manufacturer-specific focus, but they still have good information that can be applied to almost any oscilloscope.
If you want to get really into the power supply and do high-side measurements you'll need an isolated differential probe, which can cost as much as an inexpensive oscilloscope, but for DC output measurement you shouldn't need anything special. Current probes are a lot more affordable if you're interested in looking at loads or current fluctuations/harmonics, but that's more useful after you've figured out a bit more what specific properties you're trying to measure.
Edit: I forgot to mention that the EEVblog forums are a good resource also, but they sometimes aren't as friendly as they could be towards people just starting out.
Everything in computer science is such a rabbit hole, great field to be in.