R1 may be 10k and R2 100k. The transistor can be the BC548 and instead of the small lamp we can use a series LED with a 1k resistor. D1 is germanium and C1 is 10 nF. C2 can be 47 nF.
This circuit appears elsewhere on this site, but from different sources. Using the LM3900, we find this...
Mouser Electronics is providing integrated circuits DRV8885 from Texas Instruments consisting of...
This shield can be used both to interface microcontroller circuits or TTTL. The resistor in series...