LIQUID_NITROGEN_LEVEL_CONTROL

Published:2009/7/14 0:35:00 Author:May | From:SeekIC

1N4005 diode serves as sensor. Junction voltage of diode increases from 0.7 V at room temperature to 1.05 V when in liquid nitrogen. Voltage change is used to activate amplifier that controls solenoid valve through solid-state relay.1K pot R adjusts circuit sensitivity; this can be set so pump starts refilling of container when liquid is as much as 2 inches below diode, to eliminate frequency recycling LED indicates valve status．－V.J.H. Chiu, Diode Sensor and Norton Amp Control Liquid-Nitrogen Level, Electronics, Feb.2,1978,p 117.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/LIQUID_NITROGEN_LEVEL_CONTROL.html

Print this Page | Comments | Reading(3)