Latching types of general purpose relays typically have ______ coils.

Latching types of general purpose relays typically have two coils. These relays are designed to maintain their position even after the operating signal is removed, which is why they require two coils: one for setting (or energizing) the relay, and the other for resetting (or de-energizing) it. This configuration allows the relay to be energized or de-energized based on the current supplied to each coil, enabling it to hold its state without continuous power. This characteristic makes latching relays particularly useful in applications where maintaining a state is essential without constant energy consumption.