This circuit is from a 90s Radio Electronics. The resistors must be precision types and the transistor is a general-purpose type. The operational admits equivalent.
E) This audio filter was found in the August 1993 issue of Radio Electronics magazine. It cuts low...
This defrost alarm starts from an interesting idea. A small magnet on an ice stone is trapped at the...
This circuit was obtained from a Linear Technology manual from the 1990s. The components may have...