00:00Varister vs TVS Diode, Which Protects Circuits Better
00:04Ok, real question, if you're building anything with a USB port, a power line, or a relay coil, something will
00:10try to fry it eventually.
00:12I've been digging through the deals on varisters and TVS diodes, and honestly the answer isn't as obvious as the
00:18spec sheets make it look.
00:20TVS diodes are brutally fast and precise.
00:24Varisters are slower but soak way more energy.
00:27Let's get into the 5 options I found, because the price gaps here are wild.
00:32First up, the 50-piece pack of SMBJ 5.0CA bi-directional TVS diodes in the SMB-DU214AA package.
00:40This is the originally 3.50 seconds part with the standard KE marking, rated at 5 volts, 600 watts, and
00:4765.2 amps of peak clamping current.
00:50That's the one I'd actually trust for a bench full of 5 V rails.
00:54It's about $5.11 for 50 of them, so you're talking roughly 10 cents a piece, cheap insurance for the
01:00amount of fried logic boards I've seen.
01:02If your board runs on 5 V and you care about tight clamping, start here.
01:07Second is the 50-piece mixed pack, and this one might be my favorite find.
01:12Same SMB package, bi-direction, but you get 10 different breakdown voltages, 5 V, 6 V, 7.5 V, 12
01:19V, 18 V, 24 V, 28 V, 33 V, 100 V, and 188 V.
01:26$3.09 for the whole lot.
01:29You get 5 of each voltage.
01:31That's the I-don't-know-what-my-circuit-needs-yet-pack hobby tinkerers, repair benches, anyone prototyping with multiple rails.
01:39Highest-rated item on this list too, so I'd grab it before anything else.
01:44Third, we're getting into barista territory.
01:47This is the 5-piece set of S14K275 inline MOVs, 14mm discs rated at 275 V and 300 VAZ, the
01:55classic TDKB72214S271K151V87 part.
02:00This is a main-site protection device, and it's the reason people save a rister when they mean surge protection
02:06on an AC line.
02:08$1.68 for 5.
02:10It's noticeably slower to clamp than a TVS, but it absorbs a huge surge and then bleeds the energy off.
02:17For 120 or 240 V AC, this is the right tool, not a TVS diode.
02:23Fourth, another TVS pack, and this is the budget bulk option, 20 pieces of SMBJ 5.0CA bidirectional 5V diodes
02:31at $1.34.
02:33That's under 7 cents each, so it's the cheapest way to stock up on 5V protection without buying 50.
02:40The listing calls it compatible with P6KE 5.0CA-style applications too, and it's been sold over 3,600 times
02:47with a 4.9 rating.
02:49Same fast, precise clamping as the bigger pack.
02:53Solid if you only need 5V and you need a lot of them.
02:57So here's the short version, TVS diode for fast, low-voltage signal protection, USB, USB-C, sensor lines, 5V rails.
03:05Barista for AC mains and big energy dumps.
03:09Some builds use both.
03:11All 5 links are in the description below.
03:14If this saved you a fried board, hit like, and subscribe, I'll be comparing more of these protection parts soon.
