5V / 12V / 15V SMPS Testing! (Line & Load Regulation)

Three buck converters, three sets of tests. What could possibly go wrong? We’re measuring transient response, line regulation, load regulation, and efficiency of these critical power supplies. Check it out!

Next topics:
Ferrite Bead & 5kV Isolated Flyback Converter
–
Follow us on:

Amazon Affiliate Links (Thank You!):

Links:

[normallyopen]

Good work =) I've been thinking about your PTC efficiency problem. I was thinking of a solution similar to a soft start bypass circuit, with some sort of latching relay?
If you give up on indicators, a latching micro relay with a good enough break rating might be suitable? Given we're talking 24v and less, automotive people seem to be fine with doing things solid state now? (i.e. FET's, or 12v/24v load switch IC's). Personally for 5v and less, I just use really cheap 5v load switches. MIC2007's are cheap enough microchip ones, although jw7115's and others from lcsc are even cheaper. For 12v/24v load switching with OCP I can't remember the IC's specifically, but there were ones from infineon and others?

You could "Roll your own OCP" with a relay of your own?
I prefer having a physical switch. The hard part is finding the break performance of a latching relay with an actual switch as well. I don't know whether one can get DC circuit breakers with switches/physical actuators/position indicators?

I've found widespread availability and use of gruner 721 relays for AC applications. I haven't been able to find a local AU distributor for their DC contactors. Plus they're expensive?
HFE10(hongfa, they look like they have larger ones as well?) seems to be what I can find cheaply. The datasheet doesn't have a curve for electrical endurance, but 5k ops breaking 60A 250vac resistive load is nice, but doesn't help with DC i think? I recall a toshiba relay with a full curve for DC breaking, with good rating up to breaking 10A, but that wasn't latching. I don't have a link, plus it took ages to find, going through every relay on mouser pretty much =P HFE10 has 6k ops for electronic ballast 277VAC@ 16A, whatever that means. Perhaps with a PTC or TVS diode in parallel that would limit damage to the contacts? (Ed -> magnetic blowouts is another option, although I don't think the cheap or low current, "low" voltage stuff is going to need that?) I don't have experience designing around saving relays, typically I just buy the right contactor/relay =P

I've also found magnetic latching automotive relays, they don't have position indicators and/or manual reset stuff though?

[normallyopen]

Someone asked about a 12v push pull and voltages on primaries, but the comment dissapeared for me after I replied? Must have been answered?

For completeness: I've found the TI power topology handbook handy for what the waveforms and equations should be. (slyu036, Markus Zehendner, Matthias Ulmann).

The question related to the primary switch voltages of the 12v converter being 24v. Given CCM the max voltage is 2 * vin, given DCM -> Vin + (vout + vf)*np/ns. I initially quoted the CCM as that's what I remembered =)