用XMT──121温控仪实现温度越限自动通断电控制的措施

Measures for Automatic Switching Power Supply According to Upper-lower Limit of Temperate with Temperature Controller of XMT──121

当温度超越上、下限时，仅用ＸＭＴ－１２１ 仪表不能方便地实现自动通断控制电功能。对此，采用ＸＭＴ－１２１ 仪表与５５５芯片构成的滞环比较电路，当温度超越上、下限时，可实现自动通断电功能。

It is not easy achieved to automatically switch power supply according to upper-lower limit of temperature only using temperature controller of XMT- 121. A hysteresis loop comparison circuit which is composed of XMT- 121 and 555 chip can be used instead.