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Ethernet Port Dead After a Lightning Strike or Surge Test: Is It the LAN Transformer or the PHY? | VOOHU

Ethernet Port Dead After a Lightning Strike or Surge Test: Is It the LAN Transformer or the PHY? | VOOHU

A dead Ethernet port after a surge does not necessarily mean the LAN transformer failed. How surges reach the port, a power-off method that measures each side of the transformer, how to use an insulation tester without being fooled by the GDT, three common pitfalls, and a 10-point repair checklist.

Can a Tab-Up RJ45 Jack Replace a Tab-Down One? Latch Orientation, Mirrored Pinouts and LED Position Checks | VOOHU

Can a Tab-Up RJ45 Jack Replace a Tab-Down One? Latch Orientation, Mirrored Pinouts and LED Position Checks | VOOHU

Swapping a tab-up RJ45 jack for a tab-down one? Of 774 VOOHU RJ45 parts, only 85 single-port MagJacks are tab-down, and just 2 of those are SMT, both 10/100M. Why a mirrored jack swaps pairs A and D beyond what Auto-MDIX can fix, plus LED, stacked-port and panel checks.

SFP Module Running Hot? Vented vs. Heat-Sink Cages and the Lower Port of a 2×1 Stack | VOOHU

SFP Module Running Hot? Vented vs. Heat-Sink Cages and the Lower Port of a 2×1 Stack | VOOHU

SFP module temperature alarms? Only 13 of 205 VOOHU SFP, SFP+ and SFP28 cages carry a heat sink, and all are single-row 1×N; none of the 135 stacked 2×N parts do. How to read DDM, reassign hot modules, check airflow and allow the 4 mm clearance a heat-sink cage needs.

Can an Audio Isolation Transformer Run on a 48 V Phantom-Powered Line? Silent Mics, Center Taps and 7 mA DC Bias | VOOHU

Can an Audio Isolation Transformer Run on a 48 V Phantom-Powered Line? Silent Mics, Center Taps and 7 mA DC Bias | VOOHU

Can an audio isolation transformer sit on a 48 V phantom-powered mic line? In series it blocks phantom and silences condenser mics; at a preamp input the winding carries only microamps until one leg shorts to ground and drives about 7 mA through it. Using data for all 27 VOOHU WHTT audio transformers, this article covers center-tap screening by pin count, fault currents and demagnetisation.

RJ45 Gold Plating 3U vs 6U vs 50U: Mating Durability, Contact Resistance and Coupler Selection | VOOHU

RJ45 Gold Plating 3U vs 6U vs 50U: Mating Durability, Contact Resistance and Coupler Selection | VOOHU

What is the difference between 3U, 6U and 50U gold plating on RJ45 contacts? Plating thickness sets mating durability and corrosion resistance, not bandwidth. Using VOOHU Cat5e and Cat6 coupler data, this article explains how thin gold fails, which grade fits each application, where cost can be cut and how to verify plating on samples.

Choosing a Chip LAN Transformer: Six Sizes Mapped to Data Rate, PoE Class and OCL | VOOHU

Choosing a Chip LAN Transformer: Six Sizes Mapped to Data Rate, PoE Class and OCL | VOOHU

A full comparison of the 23 chip LAN order codes VOOHU offers across six sizes. 2012 and 3216 are Cap+CMC and contain no transformer at all; only 3532A, 4532B, 4532E and 5335A are true surface-mount LAN magnetics. The parts are laid out as a data-rate by PoE-class lookup, explaining why a higher PoE class forces a larger package, why 10G needs only 120 uH, and where 4532B and 4532E diverge despite sharing a size.

Ethernet Switch IC Uplinks: What “5+2” and “8+2” Really Mean, RGMII Levels and the 1.1 V Core Rail | VOOHU

Ethernet Switch IC Uplinks: What “5+2” and “8+2” Really Mean, RGMII Levels and the 1.1 V Core Rail | VOOHU

A parameter-by-parameter comparison of the 20 JLSemi Ethernet switch ICs distributed by VOOHU: what the “+N” uplink in 5+2 and 8+2 actually is, the three things an Interface Mode of NA rules out, matching RGMII IO levels at 1.8/2.5/3.3 V, which three types really support a 1000Base-X fibre uplink, the two notations for the 1.1 V core rail, and what to use when JL5109C, JL5110C, JL6105 and JL6108 have no industrial version.

How to Choose an ESD Protection Diode for an Ethernet Port: 0.3-1.2 pF Capacitance, Discharge Ratings and Package Fit | VOOHU

How to Choose an ESD Protection Diode for an Ethernet Port: 0.3-1.2 pF Capacitance, Discharge Ratings and Package Fit | VOOHU

ESD testing passes but the gigabit link goes unstable once protection is fitted? This guide sets the selection order by capacitance, voltage grade and structure, compares ten VOOHU ESD, GDT and MOV parts, and lists the board-level checks.

SFP Module Not Detected? Check Mod_ABS, I²C Management and WHSFP Connector Contacts | VOOHU

SFP Module Not Detected? Check Mod_ABS, I²C Management and WHSFP Connector Contacts | VOOHU

A practical four-layer check for SFP presence, 3.3 V power, I²C management and board-side connector contact.

How to Test a Current Transformer: WHPT-EE050-009 Continuity, DCR and Loaded-Waveform Checks | VOOHU

How to Test a Current Transformer: WHPT-EE050-009 Continuity, DCR and Loaded-Waveform Checks | VOOHU

A practical WHPT-EE050-009 troubleshooting guide covering continuity, DCR and loaded-waveform checks for missing signals and nuisance trips.

How to Select a Power-Line Common-Mode Choke: Comparing Five VOOHU WHACM15A60R Options

How to Select a Power-Line Common-Mode Choke: Comparing Five VOOHU WHACM15A60R Options

Compare five WHACM15A60R power-line common-mode chokes by 100 MHz impedance, current rating, and DCR to build a practical shortlist.

Can WHDG18101G Replace WHDG18110G? Loss, Pinout and Height Checks for 18-Pin Gigabit LAN Transformers | VOOHU

Can WHDG18101G Replace WHDG18110G? Loss, Pinout and Height Checks for 18-Pin Gigabit LAN Transformers | VOOHU

Compare WHDG18110G and WHDG18101G insertion-loss limits, centre taps, pin mapping and board-level checks before approving an 18-pin Gigabit LAN transformer replacement.

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