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.
I found this circuit in a doc umentation from the year 1968. It uses germanium transistor and has...
This circuit produces sounds that depend on the measured voltage and that can be compared with a...
This circuit was found in American documentation from the 90s. It serves as an amplifier for a...