Factors to Consider When Selecting a Current Sense Resistor
A current sense resistor (or shunt resistor) is an electronic circuit element used to gauge the flow of current. The resistor converts the current into a small, proportional voltage that can be measured and monitored by an external voltmeter. This is a simple and effective technique of gauging the current flow in an electrical circuit or system. Kindly visit current sense resistor manufacturer factors to consider when selecting a current sense resistor .
The Value of the Resistor
The current sense resistor needs to be sized carefully so that it has the minimum effect on the circuit whilst also reducing power dissipation. This balance is often difficult to achieve in design.
This is mainly because the resistor value is directly related to the voltage developed across it. The voltage subtracts from the power delivered to the load and can upset closed-loop control, whilst it also reduces system efficiency as it represents wasted power not going into the load.
Similarly, the temperature coefficient of resistance is important for high-current systems where the heat dissipated in the resistor can have an impact on reading accuracy. There are many resistors that are made from special materials and construction techniques, which give a very low TCR.
There are other issues such as noise and the self-heating of the resistor, which can cause it to drift away from its nominal value. This can be particularly noticeable when it is placed in an environment where there is a lot of electrical activity and where a high current may be present.
These factors are not to be underestimated and they should be considered when selecting a current sense resistor for a specific application. It is also necessary to consider the power rating of the current sense resistor as this will have an effect on both PC-board layout and the thermal situation of the resistor itself.
Another issue that should be considered is the surge tolerance of the current sense resistor. These can be a real problem especially when designing a motor or some other system with sudden increases in the current. A current sense resistor that has a high surge tolerance is needed to deal with these situations.
The technology that is used to produce current sense resistors should also be considered. The majority of current sense resistors are made from bulk metal, and this can offer benefits such as good surge tolerance and a very low TCR.
However, other technologies such as wire wound and metal foil can also be very good for current sensing applications. The use of these technologies can also provide benefits such as miniaturization, high precision, and low TCR.
A wide range of current sense resistor are available from IBS Electronics. These include shunt resistors, chip resistors, and SMD current sense resistors. They are able to offer miniaturization down to 01005 size, with the ability to be very accurate and with high power up to 3W.
They can be supplied in many different forms and sizes, including lead-free and RoHS compliant designs. They are available in the following ohm values:
The selection of a current sense resistor is a complicated process and should be done with great care. It is important to find a resistor that has the appropriate surge tolerance, the highest power rating possible, the best temperature coefficient of resistance, and can meet any other needs such as isolation and safety considerations. Check out this related post that will enlighten you more on this link: https://en.wikipedia.org/wiki/Talk%3AResistor.