This circuit is from American documentation from the 1980s. The transistors are general purpose types and the relay can be 6 or 12 V depending on the supply voltage.
This CMOS circuit divides the frequency of a rectangular signal up to 2 MHz by 6. The supply...
PIC16F19197 Microcontroller Family Combines Battery-Friendly LCD Drive with Core Independent...
This source draws a fixed constant current of 1 mA using a Norton operational amplifier. Other...