| 摘要 |
<p>The two inputs to the control system are electrical switches operated by the room temperature thermostat (2) and the domestic hot water thermostat (12). The output of the system controls the position of a three-way valve which can divert the central heating medium, e.g. hot water from the radiator feed to the heat exchanger in the domestic hot water tank. When the hot water thermostat (12) closes it initiates a delay (18) after which a transistor (T1) energises a relay (19) which has a contact (20) in parallel with the room thermostat (2). The output of the water thermostat is also fed via another delay (22) and another transistor (T2) to energise a second relay (23) which feeds power to the motor of the three-way valve.</p> |
