Diverter resistors and alloy resistors have some overlap in materials, design purposes, and core characteristics, but they are not completely equivalent concepts. Here are their differences and connections:
1、 Definition and core differences
|Characteristics | Shunt Resistors | Alloy Resistors|
|Core Definition | A low resistance resistor designed specifically for current detection, which indirectly measures current through voltage drop. |Refers to resistors made of alloy materials such as manganese copper and constantan, with a wider range of applications and may include shunt devices. |
|Design Goal | High precision current detection, balancing low resistance, low temperature drift, and high power carrying capacity. |Stable material properties (low TCR), suitable for precision measurement, current limiting, voltage division and other scenarios. |
|Resistance range | Extremely low resistance (0.01m Ω~100m Ω). |Wide range (0.1m Ω~several Ω). |
|Typical application | Current sampling (such as BMS, motor drive). |Current detection, precision instruments, power distribution, high-frequency circuits, etc. |
2、 Differences and Similarities between Materials and Structures
Material commonality
Both may use manganese copper, Constantan, or nickel chromium alloys due to their low temperature coefficient (TCR) and high stability.
For example, shunt resistors commonly use manganese copper alloys, while alloy resistors may also use the same material.
Structural differences
|Characteristics | Diverter Resistance | Alloy Resistance|
|Resistance Implementation | Achieving extremely low resistance through ultra short and ultra wide conductor paths (such as flat metal strips). |By adjusting the alloy composition and structural design to cover a wider range of resistance values. |
|Heat dissipation design | Enhanced heat dissipation structure (such as copper substrate, large-area solder pads). |Designed according to power requirements, special heat dissipation may not be necessary. |
|Terminal type | mostly four terminal (Kelvin connection) to eliminate the influence of contact resistance. |Usually two terminals, some precision models use four terminals. |
3、 Comparison of application scenarios
Diverter resistor
Core scenario: High current detection (such as new energy vehicle batteries, industrial power supplies).
Typical parameters:
Resistance: 0.5m Ω (Example: Rohm GMR 320).
Power: 10W~1000W.
TCR: below ± 25 ppm/° C.
Core scenario:
Precision instruments (such as medical equipment, testing instruments).
High frequency circuit (low inductance alloy resistance).
Current limiting protection (such as safety resistors at the power input).
Typical parameters:
Resistance: 0.1m Ω~10 Ω.
Power: 0.1W~10W (higher for some high-power models).
TCR: below ± 50 ppm/° C.
4、 Summary of Key Differences
|Dimension | Diverter Resistance | Alloy Resistance|
|Core Function | Optimized for current detection, emphasizing low resistance and high power. |Guided by material characteristics, with a more generalized application (possibly including diversion function). |
|Resistance range | Extremely low (m Ω level), sacrificing resistance range in exchange for current detection capability. |Covering low to medium resistance values, it is more flexible in applicable scenarios. |
|Design complexity | Complex structures such as heat dissipation and four terminal connections need to be considered. |The structure is relatively simple, and some models can replace ordinary resistors. |
5、 Comparison of actual cases
Diverter resistor (example: Bourns Riedon) ™ Series)
Purpose: Current sampling for solar inverters.
Parameters: Resistance 0.025m Ω, rated current 6000A, TCR ± 20 ppm/° C
Structure: Copper bar bolt installation, four terminal design.
Alloy resistance (example: Vishay WSN series)
Purpose: Power supply current limiting or precision voltage divider.
Parameters: Resistance value 0.01 Ω~0.5 Ω, power 3W, TCR ± 75 ppm/° C
Structure: Surface mount package (2512), two terminal design.
6、 Selection suggestions
Current detection required: prioritize selecting shunt resistors (four terminal, low TCR).
Stable resistance required: Alloy resistors (such as precision voltage divider circuits).
High frequency scenario: Choose low inductance alloy resistors (non shunt specific models).
Diverter resistors are a subset of alloy resistors, specifically optimized for high current detection scenarios; The scope of alloy resistors is broader, including both shunt and other precision or power applications. The two overlap in materials, but have different design goals and performance focuses.