| 摘要 |
<p>A prepayment water supply system comprises a prepayment unit having a receptacle for receiving a prepayment token in the form of a key, and a solenoid-operated valve controlled by the prepayment unit for controlling the water supply. The key has a memory containing credit and identification data, and the prepayment unit closes the valve when the credit represented by the credit data is exhausted. However, a bypass passage is provided which permits a supply of water at a relatively low flow rate when the valve is closed, so that enough water for drinking and filling lavatory cisterns (albeit very slowly) continues to be supplied. <IMAGE></p> |
