This circuit was found in a documentation of the 80s, having didactic purpose. For R1 values between 10k to 1M can be used. Transistors are general purpose types.
We found this circuit in a publication on operational amplifiers from the 1980s. The circuit does...
This ammeter measures currents in 5 ranges from 50 uA to 0.5 A using a 40 uA instrument, which can be...
This circuit indicates the volume of an audio signal in a different way. The circuit is from 1997...