摘要 |
<p>The specification discloses a circuit for monitoring the status of an ultraviolet (UV) light bulb in a water treatment system. The circuit uses either transformers or zener diodes with opto-isolators to monitor the voltage across the bulb. A logic signal is emitted when abnormally high voltage is detected, for example, indicating that the bulb is burned out, broken, or missing. A logic signal also is emitted when abnormally low voltage is detected, for example, indicating that the starter circuit is short circuited or that power is interrupted. <IMAGE></p> |