| 摘要 |
<p>A central heating system is controlled by semiconductor temp. sensors in association with electronic circuits to provide linear response of the heating system. The temp. of the heating fluid is measured by a sensor (1) and is converted by an amplifier (2) to the correct level and polarity for comparison (7) with a signal from a summing circuit (6). The summing amplifier receives signals from a temp. sensor (3) and from a user control as well as from the comparator (7) which enables the hysteresis (h) to be set. A differential input amplifier (10) drives relays (11, 12) controlling electrovalves for proportional control while all or nothing control is effected via an amplifier (8) and relay (9) from the comparator.</p> |
