Varistores

10D511K

10D511K - 510V 10mm MOV Varistor Surge Protector | TYEE

The TYEE Products Inc 10D511K is a 10 mm radial leaded metal oxide varistor (MOV) rated 510 V varistor voltage at 1 mA, with a maximum clamping voltage of 845 V, an AC working voltage of 320 V r.m.s., and a DC working voltage of 415 V d.c. Housed in a through-hole disc package with two radial leads, it provides surge and transient overvoltage protection for one circuit. A metal oxide varistor is a voltage-dependent, nonlinear resistor built from sintered zinc oxide grains with metal oxide additives. In the power-management hierarchy of circuit protection devices, the MOV sits alongside TVS diodes, gas discharge tubes, and fuses: it is a voltage regulator of sorts for transients, clamping surges by dropping sharply in resistance above its breakdown threshold. MOVs absorb the bulk of surge energy in AC line applications, typically working with downstream fuses, GDTs, and TVS devices in a coordinated protection scheme. Key features of the 10D511K include a 459 V to 561 V varistor voltage window at 1 mA, an 845 V maximum clamping voltage at rated surge current, a single-pulse energy rating of 69 J, and a peak surge current class of 2.5 kA for an 8/20 us waveform. Its 10 mm disc size balances energy absorption capability against footprint, and a typical capacitance of about 70 pF makes it suitable for 50/60 Hz AC line use without significant loading. The device follows the industry-standard 10D511K naming convention: 10 = 10 mm disc diameter, D = disc, 511 = 510 V varistor voltage, K = +/-10% tolerance. The zinc-oxide ceramic grain structure gives it a V-I curve resembling back-to-back Zener diodes, enabling bidirectional clamping of both positive and negative transients on AC lines. Degradation occurs gradually after repeated surge exposure, so designs should follow derating and failure-mode guidelines from the manufacturer datasheet. Typical applications include AC mains input protection in switch-mode power supplies, industrial control panels, home appliances, LED drivers, telecom power front ends, and surge-protected outlets, where the MOV clamps lightning-induced and switching transients before they reach downstream electronics. For design, always place a fuse upstream of the MOV: at end of life an MOV can fail short and overheat, so an agreed disconnection method is mandatory per safety practice. This page synthesizes distributor pricing, cross-brand drop-in alternatives, and practical design notes not found in any single manufacturer datasheet.