| 摘要 |
PURPOSE:To provide a reliable optical liquid level sensor which can detect removal or insufficient contact of a connector immediately and can deal there with appropriately. CONSTITUTION:The optical liquid level sensor comprises a light emitting element D, and a light receiving element Tr, e.g. a light receiving diode or transistor, and detects presence of liquid based on the light emitted from the light emitting element D and reflected, transmitted or refracted. The light receiving element Tr is connected in parallel with a voltage division resistor R3 or a bias resistor 15 connected with the base of the light receiving element Tr. Alternatively, a first resistor is connected with the light receiving element Tr on the collector side thereof and a second resistor is connected in parallel with the light receiving element Tr on the outside of the optical liquid level sensor. |
