This detector uses an unusual sensor today. The circuit is from an 80s documentation. Its sensitivity is 10 ppm. The transformer has two secondary voltages.
This circuit is the basis of a symmetrical 15 V supply. MC1468 can also be used. They are not...
The integrated circuit in this application is from the 80's, not being common nowadays. It...
This circuit was obtained in an old magazine from the 1970s. The circuit can still be assembled with...