| 摘要 |
An alarm device for monitoring the watering needs of a plant which comprises a stick surmounted by a cylindrical box containing the electrical elements. The stick is buried in the soil of a pot holding a plant. The alarm device is powered by a battery easily installable and consists of a conductive probe detector located at the buried end of the stick. It also comprises a first integrated circuit which is switched by a backwards connected amplifier acting as a very high impedance switch which minimizes power consumption. The circuit emits a series of pulses when a threshold resistance level is reached. These pulses trigger a melody integrated circuit which produces a pleasant singing melody destined to draw the attention of the plant grower to the watering needs of a plant. The tune is repeatedly reproduced until the soil resistance detected by the probe detector has exceeded a threshold resistance level.
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