The circuit below is suggested by National Semiconductor in technical documentation on the LM3909. The circuit is powered by a single battery and has a very low consumption.
This assembly circuit using a small motor as a generator was found in Radio Electroics magazine from...
The operational amplifier taken as an example is uncommon today, but the configuration can be made...
This simple TTL circuit generates sequences of musical notes that can be determined by adjusting R5 and...