| 摘要 |
<p>In a pressure switch, which emits an electrical switching signal as a function of the magnitude of a pressure which is supplied to it, which electrical switching signal assumes a first value when the pressure is less than the threshold value and which assumes a second value when the value is greater than the threshold value, the threshold value is adjusted-assuming that this is provided at all-by hand, for example by moving a cam disk which is coupled to a rotary knob. In order to adjust the threshold value by an electrical signal, the pressure is supplied to a pressure sensor, which emits an electrical output signal, which is a measure of the pressure which is supplied to the pressure sensor. The pressure switch is supplied with an electrical input signal which is a measure of the threshold value. The electrical output signal from the pressure sensor and the electrical input signal are supplied to a logic circuit, which emits an electrical switching signal which assumes one of two values as a function of the magnitude of the difference between the electrical signals which are supplied to it. The pressure switch is used generally for signaling on reaching a pressure which can be preselected. The pressure switch is used in particular in automation devices.</p> |
