演示用套裝熱繼電器
熱繼電器是一種利用雙金屬片受熱彎曲特性而控制電器通斷的器件,它被廣泛應用於怛溫箱、孵卵器、電熱水器、 電熨斗、熱帶魚魚缸等多種器具中的怛溫控制。當熱繼電器較快速地控制電路的通斷時,它又成了一個自動的閃光開關,用於汽車方向燈、燈塔、節日燈及廣告燈等電光具的反覆自動閃光。本演示用熱繼電器將向學生清楚地展示熱繼電器的構造和它的怛溫控制和自動閃光的原理。
整個電路很簡單,一目了然,即把熱繼電器的二個白銀觸頭與燈泡一起串聯在市電電路(220V)中。假如開始時雙金屬片1是平直的,二白銀觸頭相互接觸,則接通碗電源後雙金屬片1會由於其下方燈泡的加熱而向下彎曲,這時二觸頭相分離,電路斷開,燈泡熄滅而停止加熱。接著雙金屬片1開始冷卻而漸立變直,二三十鍾後其端部的觸頭b又恢復與螺絲下端觸頭a的接觸、燈泡又亮oooooo過二三十秒後又自動熄滅oooooo這樣熱繼電器就成了個自動的持續通斷的閃光開關。
Item no : JHL949

Thermostat for Demonstration
This device is generally applied on most thermostat control electrical applicance, e.g. temperature control, oven, incubator, electrical boiler, electrical iron, cookers etc.. It control the cut off / on electrical supply, another application on car flask direction light, lamptower , advertisement lamp system.
This apparatus clearly show the structure of thermostat and its mechanism of operation. Thermostat is operated by 220V lamp bulb , bimetallic cut off circuit , when lamp lighting, heat energy made the bimetallic strip bent, switch on system 20minutes , then electrical supply automatically cut off, lamp dark, system cut off until bimetallic strip contact point 1 to restart the system again. So light bulb light/dark alternately and system on and off too.
Item no : JHL949

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