This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the hard-to-obtain component of our day. It is for reference only.
August 2016 - It can be found at Mouser Electronics the new sensors light to digital OPT3002 from...
This circuit functions as a thermostat triggering a relay when the boil control temperature...
This circuit can monitor the charge and discharge of batteries. The circuit is from a Linear...