The frequency of this circuit depends on C1 and, for the indicated values, it is 1 kHz. Equivalent operational amplifiers can be used, and the power supply must be symmetrical.
Many collectors of records, tapes and even audiophiles often keep recordings on tapes that...
This simple circuit, from a 2006 documentation, activates a 12 V lamp in the event of a power...
We obtained this configuration from an old RCA manual of linear integrated circuits. The...