This circuit was found in a National Semiconductor manual from the 1980s. The integrated circuits used are equivalent. Note the need for a symmetrical power supply.
This circuit triggers a relay when the light that falls on the LDR is cut off. The sensitivity is adjusted...
With this circuit any number of 4017 integrated circuits can be connected in series. The circuit is...
This circuit for model making was found in an English documentation. The SCR can be the TIC106, and...