This variable frequency oscillator with the 4093 was found in a Popular Electronics from the 90s. The table gives the component values for various frequency ranges.
This simple circuit controls the brightness of an LED from LDRs, NTCs, PTCs or other resistive sensors....
This remote listening device was found in documentation from the 50's. The transistors used are...
This circuit came out in a Modern Electronics from June 1990. In it we have a low frequency...