What is commonly used to adjust a time delay control on a furnace circuit board?

DIP switches are commonly used to adjust time delay controls on furnace circuit boards because they provide a reliable and precise way to select various options based on the configuration needs of the system. These switches allow technicians to set specific settings or delays by flipping small switches to the on or off position, which corresponds to different time delay intervals specified by the manufacturer.

This method is particularly advantageous because DIP switches are often clearly labeled and can handle multiple adjustments in a compact format, making it easier to customize the operation of the furnace. The other options, while they may exist in different contexts or device interfaces, are not typically associated with the specific task of adjusting time delay controls on circuit boards in HVAC systems.