情境
A hobbyist needs a readable BFO metal detector schematic that shows the two 555 oscillator stages, passive mixer/detector, and LM386 audio output with a clear ground return.
這張圖裡有什麼
看懂背後的決策。
01
Dedicated SEARCH_OUT and REF_OUT nets keep the two 555 oscillator blocks separated before mixing.
02
A diode detector followed by R3/C6 low-pass filter extracts the beat note.
03
Rload represents an 8 ohm speaker so the audio output is a valid two-pin load.
Use this netlist when drawing BFO-style detector circuits where functional IC blocks and clear net names matter more than internal 555 pin-level detail.