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Small power adapter with 7.9x5.5mm male plug and big square USB female port

eForChina

eForChina 7.9x5.5mm Male to Big Square USB First Gen Female Power Adapter

SKU CH-W68D-4TYMB

Converts a 7.9x5.5mm power plug to a first-generation big square USB female connector for ThinkPad, ThinkBook and Xiaoxin laptops

  • Changer TypePower Adapter
  • Converts 7.9x5.5mm barrel plug to legacy square USB power input
  • Brand-new adapter built to original quality standards
  • Ultra-compact design fits in any laptop bag or pocket
  • Lightweight construction adds virtually no bulk for travel
  • Direct replacement for ThinkPad, ThinkBook and Xiaoxin chargers

Compact Power Adapter for Legacy ThinkPad

This 7.9x5.5mm male to big square female adapter connects first-generation square-tip chargers to compatible ThinkPad, ThinkBook and Xiaoxin laptops. It serves users who need to power older devices with a legacy power supply. The passive design requires no drivers or configuration. It addresses a specific connector mismatch without adding bulk.

Passive Connector With No Active Electronics Under

The adapter contains no voltage regulation or active components, so its behaviour under sustained load matches the source charger and the laptop's own power management. Current passes directly through the contact surfaces without conversion. Heat generation is limited to the resistance of the metal contacts themselves. Reliability depends on the quality of the mating connection at both ends.

Lightweight Plastic Housing Suited to Travel

The moulded plastic body is small and lightweight, making it easy to carry in a laptop bag or pocket. A snug fit on the 7.9x5.5mm male tip and the big square female socket prevents accidental disconnection during daily use. No cables or strain-relief features are included, so the adapter sits inline between the charger and the device. The simple construction supports frequent plugging and unplugging.

Highlights

  • Converts 7.9x5.5mm barrel plug to legacy square USB power input
  • Brand-new adapter built to original quality standards
  • Ultra-compact design fits in any laptop bag or pocket
  • Lightweight construction adds virtually no bulk for travel
  • Direct replacement for ThinkPad, ThinkBook and Xiaoxin chargers

Specifications

Changer TypePower Adapter

Questions about this item

Does the 7.9x5.5mm male connector draw power continuously or only when a device is attached to the big square female port?

The adapter has no active electronics, so it passes power only when the host supply is live and a device is connected to the big square female interface.

What host power supply must I already own for this 7.9x5.5mm male plug to fit?

You need a ThinkPad, ThinkBook or Xiaoxin charger whose output tip measures 7.9 mm outer diameter and 5.5 mm inner diameter.

Will the big square first-generation female port accept the newer rectangular USB-C tips found on recent ThinkPad chargers?

No, the female port is sized for the legacy big square connector only and will not mate with the smaller USB-C or rectangular tips.

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