Scratch is the scratching noise that occurs mainly with old records. This high frequency noise is eliminated by the filter found in the February 1990 issue of Radio Electronics magazine.
Based on Allegro's A6275, this circuit controls the brightness of various displays. The circuit is valid...
We found this circuit on the internet. The components are current, and the time depends on C1...
This precision bench test circuit can deliver currents in a range of 10 uA to 10 mA. The circuit is...