What is not a typical input device used for two-wire control circuits?

In the context of two-wire control circuits, the primary concern is the type of device used to initiate control actions. While pushbutton switches are common and integral in various control schemes, they are not typically used as a standalone device in two-wire control circuits.

Pushbutton switches are often utilized in momentary actions where the circuit is activated only while the switch is pressed. In contrast, two-wire control circuits generally rely on devices that maintain a circuit state, allowing for continuous control without the need for constant physical interaction. Devices like toggle, selector, and foot switches are designed for more permanent states or can easily engage with mechanical feedback.

Toggle switches are frequently used to provide a stable on/off state, which aligns well with the requirements of the two-wire control circuitry. Selector switches offer a way to choose between multiple circuit paths, making them suitable for various applications requiring specific control inputs. Foot switches also allow hands-free operation while maintaining a stable circuit, making them practical in certain scenarios.

In summary, while pushbutton switches have their place, they do not typically align with the operational needs of two-wire control circuits, which favor devices that can maintain a continuous control state.