| 摘要 |
The present invention relates to a separation frequency detector circuit and a method for detection of a separation frequency in a radar level gauge. A first circuit element (1) is arranged to receive a first clock frequency, and a second clock frequency. An instantaneous value of said first clock frequency will be transferred to and held at an output Q of said first circuit element (1) once each period of said second clock frequency. A predetermined value will be transferred to and held at an output Q of a second circuit element (3) triggered by the output Q of said first circuit element (1) and said predetermined value will be cleared from said output Q of said second circuit element (3) a predetermined time period after being triggered. An output is obtainable as a short pulse with a leading edge which will be synchronized with the first change of the leading signal edge of said first circuit element (1). |
