| 摘要 |
<p>An electronic control system comprises a switch unit (1) operable by a key or like removable token and a control circuit (2, 3, 11, 30) controlled by the switch unit (1) to cut off, from a supply of electrical power (18), appliances connected to the power supply when the key or like removable token is not present in the switch unit. <IMAGE></p> |
