| 摘要 |
A comparison circuit suitable for utilization in a television. The comparison circuit includes an input adapted to be connected, for example, to an integrating capacitor (16) and comprises a trigger stage (24) adapted to switch from a first state to a second state in response to the trigger stage being activated by a gating pulse and the potential appearing across the integrating capacitor being below a first threshold level (88); a feedback circuit (34) coupled between the output of the trigger circuit to the input of the comparison circuit for latching the trigger stage in an on condition and charging the capacitor until the potential thereacross exceeds a second threshold level (94) at which time the trigger stage reverts to said first state; and a pulse generating circuit (56) coupled with the trigger stage to produce an output pulse delayed in time from the initiation of the gating pulse in response to said trigger stage being in said second state and the potential across the integrating capacitor traversing through a third threshold level (96), the value of which being between said first and second threshold levels. |
