For any electrical control system, input signals of both voltage and current are often critical for the system to operate according to the intended design and in a safe manner. While measuring voltage is often simple in that it can be measured at many points accurately, can interface with most controllers directly, and can be done without impacting the system, measuring current is usually not so straightforward. When we measure current, we often must “insert” a foreign sense element into the system to serve the purpose of measurement. To do this in a way that is accurate, requires little PCB space and few components, adds little cost and preserves the original system performance becomes the challenge. Some methods to approach this ideal will be discussed.
