Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The transistor can be a BD135 or other medium power.
July 2017 - The new touch switches from Alps SKPS series for surface mounting can now be purchased from...
Found in an 1989 R-E Experimenters Handbook, this circuit produces several sound effects that can...
June 2017 - Mouser Electronics has a broad line of Cree products for use in horticulture, such as...