How does Magsafe (Pogopin Charger) Keep the Contact Resistance Low
1. Optimal Spring Force:
The internal spring in each pogo pin is engineered to apply a consistent and appropriate amount of force when the connector is mated. This force is critical for several reasons:
- Breaking Through Oxidation:
- The spring force helps to break through any minor surface contaminants or oxidation that may have formed on the contact points, ensuring a clean metal-to-metal connection.
2. High-Quality Materials and Plating:
Base Materials:
The core components of pogo pins, the plunger and barrel, are typically made from copper or brass alloys. These materials are chosen for their excellent electrical conductivity.
Gold Plating:
To further enhance performance, these components are plated with a thin layer of gold over a nickel base. Gold is an exceptional conductor and is highly resistant to corrosion and oxidation. This is crucial because even a thin layer of oxidation on the contact surfaces can significantly increase resistance and impede the flow of electricity.
3. Contact Geometry and Design:
The shape of the pogo pin’s tip (the plunger) and the design of the contact pads on the device are optimized to maximize the contact area. A larger contact area provides more pathways for the current to flow, which reduces resistance.
Some pogo pins feature a “ball” design, which increases the number of contact points within the pin itself, further contributing to a stable and low-resistance connection.
4. Magnetic Alignment:
The “Mag” in MagSafe refers to the magnets that guide the connector into the correct position and hold it securely in place. This ensures that the pogo pins align perfectly with the contact pads on the device every time. Proper alignment is essential for achieving the intended contact area and, consequently, low contact resistance.
5. Cleanliness:
While the design of the MagSafe connector helps to keep the contacts clean, any debris or buildup can increase resistance. The spring-loaded nature of the pins can help to push away some minor debris, but keeping the connector and the port on the device clean is important for optimal performance.
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