Collaborate Disseminate
A student once asked his lab instructor why his amplifier was oscillating. After looking at it and noting the wild construction, the instructor remarked, “A better question would be why …read more Continue reading EMC Tutorial Puts You in the Loop
Tiny PCBAs and glowy VFD tubes are like catnip to a Hackaday writer, so when we saw [hamster]’s TubeCube tube segment driver we had to dig in to learn more. We won’t bury the lede here; let’s enjoy a video of glowing tubes before we go further:
The TubeCube is …read more
In the last installment of Circuit VR, we walked around a simplified buck converter. The main simplification was using a constant PWM signal. The result is that the output voltage is a fixed fraction of the input voltage. For a regulator, the pulse width will need to depend on the output voltage so that any changes in the output are self-correcting. So this time, we’ll make a regulator, although we’ll still use a few Spice elements you’d have to replace in a practical design. In particular, we’ll assume you can generate a triangle wave, which is easy enough, and produce …read more
Continue reading Circuit VR: An (Almost) Practical Buck Converter
The first thing I ever built without a kit was a 5 V regulated power supply using the old LM390K. That’s a classic linear regulator like a 7805. While they are simple, they waste a lot of energy as heat, especially if the input voltage goes higher. While there are still applications where linear regulators make sense, they are increasingly being replaced by switching power supplies that are much more efficient. How do switchers work? Well, you buy a switching power supply IC, add an inductor and you are done. Class dismissed. Oh wait… while that might be the best …read more
We always appreciate when someone takes the time to build something and then demonstrates what different design choices impact using the real hardware. Sure, you can work out the math and do simulations, but there’s something about having real hardware that makes it tangible. [Julian Ilett] recently posted two videos that fit this description. He built a buck converter and made measurements about its efficiency using different configurations.
The test setup is simple. He monitors the drive PWM with a scope and has power meters on the input and output. That makes it easy to measure the efficiency since it …read more