This circuit uses BCD switches to program the frequency to be divided. The circuit is from a Radio Electronics magazine from February 1989.
This alarm circuit is from a 1987 publication, however the components used are still modern. The...
In the figure we have a configuration that allows to test NPN transistors and with the addition of a...
We find this current meter circuit from 0 nA to 200 nA in a Linear Technology application manual....