A bed comprises: a height-adjustable lying surface； a head part, a foot part, and/or at least one side part； a motor for adjusting the height of the lying surface； and a control system for controlling the motor to adjust the height. The control system comprises at least one sensor and at least one actuator. The sensor includes: at least one actuating element that can be actuated to generate a control signal； an interface to emit the control signal； and at least one element for producing energy, by which energy needed for generating and transmitting the control signal can be generated via actuation of the sensor from the outside. The actuator includes: an interface to receive the control signal； and a switching element to switch at least one current path or an adjusting element to set at least one voltage, one current, or another physical variable based on the control signal.
