Fundamentals of Circuit Protection: Fuses & PTCs
Circuit protection against the consequences overvoltage and overcurrent conditions, whether due to internal or external faults and failures, is required in nearly all products spanning low-voltage battery-powered devices to high-voltage AC line-powered designs. In most cases, fuses and PTCs (positive temperature coefficient devices) offer the most practical and cost-effetive way to provide this protection. While these passive components often don’t get much attention, there are issues and subtleties when deciding which type and specific device to use. This fundamentals course looks at fuses and PTCs with respect to a system-level perspective, application fit, how they work, key parameters to consider, selection criteria, and even identifies situations where they are the right choice.
Bill Schweber is an electronics engineer who has written three textbooks on electronic communications systems, as well as hundreds of technical articles, opinion columns, and product features. In past roles, he worked as a technical web-site manager for multiple topic-specific sites for EE Times, as well as both the Executive Editor and Analog Editor at EDN.