This circuit makes use of components from the time it was published. The TCA151 is not a common component today. The circuit generates 10 to 10 kHz signals.
November 2016 - Texas Instruments' new TLV8802 nano-power operational amplifiers for wireless...
This sophisticated photometer that has a light comparator with LED indicator came out in an...
This is a version of the previous circuit that includes a tone modulator based on a Hartley...