X
Two transistors and a capacitor create a "heartbeat" LED effect. Long before PWM (Pulse Width Modulation) became standard, this analog fading circuit was elegant.
If your goal is to access the content, I have also listed legal methods to obtain the book at the end of this analysis. elektor electronics 304 circuits pdf
The PDF includes foil patterns for PCBs. You have three options: Two transistors and a capacitor create a "heartbeat"
Physical copies are frequently found on eBay, AbeBooks, and ThriftBooks. For a hobbyist actually intending to build the circuits, the physical book is often superior to a PDF because it allows for easier referencing while soldering. elektor electronics 304 circuits pdf