| 摘要 |
<p>A monitor circuit arrangement for traffic lights wherein energy is supplied from an alternating voltage supply source(s) to a lamp (L 1) via a controlled switch (SD 1) and energization of the unit is monitored by a voltage comparator (100) connected in cascade with a sensing latch (SL 1), the voltage comparator (100) being such that its output is activated in response to its input voltage exceeding a predetermined magnitude of either polarity relative to a common reference voltage wave, a monitored voltage representative of the voltage present across the lamp (1 1) being supplied as input voltage to the voltage comparator(100), the output of which is fed to the sensing latch set input, reset means (RPS) being provided for resetting the latch at the commencement of each cycle of the alternating supply voltage. </p> |
