Based on the well-known LM3909, this LED pulser circuit was found in American documentation from the 90's. The power supply is only 1.5 V.
An interesting timer is shown in the figure, using one of the 4 NAND gates of the integrated 4001....
General Electric suggests this circuit in a 1980s documentation. The operational of the time is...
This simple adjustable source uses a PNP transistor that can be the BD136 for even slightly higher...