Continuous Current
Normal Operating Load
State the current that the cable must carry continuously during normal device operation.
Use this high-current magnetic cable solution guide to define the complete electrical and thermal requirements before selecting a magnetic connector or finished cable assembly. The guide explains continuous and peak current, duty cycle, total loop resistance, allowable voltage drop, contact allocation, conductor design, temperature-rise validation and the information required for a custom high-current magnetic connection project.
Begin with the complete operating condition. Continuous current, peak current, duty cycle, allowable voltage drop and ambient temperature determine how the cable and magnetic interface should be evaluated.
State the current that the cable must carry continuously during normal device operation.
State the peak current, its duration and how frequently the peak occurs during operation.
Define whether the load is continuous, intermittent, pulsed or part of a repeated charging cycle.
Define the source voltage, minimum device input and allowable voltage drop across the complete path.
Review every electrical and mechanical transition from the power source to the device and back through the return path.
Plug, adapter, bare wire, PCB joint or another source-side connection.
Conductor length, structure, termination and movement condition.
Contact allocation, alignment, compression and contact resistance.
PCB pad, solder joint, FPC, internal wire or device terminal.
The complete return route must be included in resistance and temperature evaluation.
Choose the contact architecture according to the required current path, available space and complete circuit. Multiple contacts do not automatically share current equally.
Use a dedicated pair when each path can carry its assigned load within the agreed electrical, thermal and mechanical conditions.
Parallel contacts may be evaluated when one path is distributed across multiple positions. Current sharing must be validated.
A multi-contact structure can separate high-current paths from detection, identification, control or customer-defined signal contacts.
| Architecture | Main Benefit | Main Risk | Required Validation |
|---|---|---|---|
| Dedicated Supply and Return | Clear assignment and straightforward continuity documentation. | Each path carries its full assigned load. | Loop resistance, voltage drop, temperature and mating stability. |
| Parallel Power Contacts | Allows several contacts to participate in one power path. | Resistance differences may create uneven current distribution. | Individual contact condition, current sharing and partial mating. |
| Power and Auxiliary Channels | Combines power delivery with defined control or signal functions. | Incorrect grouping may affect the complete device system. | Full Pin Map, cable map, circuit and device-level validation. |
High-current performance depends on the combined resistance of the source termination, conductors, magnetic contacts, PCB connection and return path.
Add the resistance of every conductor, termination, contact and return connection.
Compare the voltage drop with the minimum voltage required at the customer device.
As current rises, power loss becomes more sensitive to resistance in the complete path.
Sample approval should cover normal operation, peak loads, repeated mating and representative worst-case conditions.
| Validation Stage | Electrical Condition | Sample Condition | What to Measure | Purpose |
|---|---|---|---|---|
| Initial Baseline | Low and normal load | New, correctly mated sample | Resistance, device voltage and temperature | Establish the reference condition |
| Continuous Load | Normal continuous current | Complete cable and fixture | Voltage drop and temperature over time | Confirm steady-state performance |
| Peak Load | Peak current and duty cycle | Representative operating sample | Transient voltage and heat accumulation | Confirm intermittent operation |
| Partial Mating | Controlled safe test condition | Incomplete or offset connection | Electrical state and abnormal concentration | Evaluate possible mis-mating states |
| After Mating Cycles | Repeat normal operating load | Sample after defined cycles | Resistance drift and temperature | Check performance change with use |
| Environmental Review | Agreed load condition | Required ambient or exposure state | Electrical and thermal stability | Confirm intended operating environment |
| Cable Flex Review | Normal operating load | Cable routed as in the device | Voltage fluctuation and local temperature | Verify outlet and strain relief |
The location and timing of abnormal heat can help narrow the investigation to the contact, conductor, termination, PCB or operating condition.
Review contact resistance, alignment, compression, contamination and wear.
Review conductor length, cable structure, routing, ambient condition and load duration.
Review conductor preparation, joint area, soldering, crimping and local strain.
Review unequal resistance, mating tolerances and whether current is actually being shared.
Review conductor damage, outlet structure, strain relief and local resistance change.
Compare resistance and temperature with the initial sample baseline.
Complete the electrical, cable, connector and validation information before selecting a product or developing a customized structure.
Select a product directory after the electrical load, contact allocation, cable length and validation conditions have been defined.
Send the continuous and peak current, duty cycle, cable length, contact allocation, allowable voltage drop, ambient condition and available drawings.