Using the 741 this circuit can be adjusted to values between 1 Hz and 100 kHz. The power supply must be symmetrical. We found it in the Radio Electronics magazine of November 1973.
Found in Radio Electronics, this filter is suitable for attenuating up to 40 dB for AM radio...
This TTL module can be used in counter and many of them can be cascaded to counts up to 99, 999,...
This circuit was found in the Texas Instruments 1996 linear applications manual. It consists of a...