This circuit is from old American documentation, using a regulator integrated circuit that is uncommon today. The diodes can be 1N4002 and the transformer has a 500mA secondary.
This circuit was found in a 1977 documentation. With it we have the direct indication, through LEDs...
In the figure we have the CMOS logic test circuit developed with the 4049. The circuit activates three...
This headlight reminder for your car was found in the May 1970 issue of Radio Electronics...