this is a recap of the [[http://yair.cc/ledB|ledB]] project {{ :pasted:20200612-085832.png?100}}

{{youtube>rnM_7NyU4k8}}

==== BOM ====
  * 1 x resistor 10K thruhole
  * 1 x resistor 10M thruhole
  * 1 x diode BA159 or alternative
  * 1 x piezo disk ~3.5Khz (datasheet)
  * 1 x BLUE led (3.5v fwd voltagedatasheet)
  * 1 x LM741 opAmpo (datasheet)
  * 2 x coin cell battery CR2032

==== Piezo ====

=== simulation ===
  * [[https://www.circuitlab.com/forums/support/topic/cdya3g85/simulating-piezo-sensor/|QA about simulation]]
  * {{:piezo_maruta-p37e.pdf}}
  * [[http://ltwiki.org/files/LTspiceIV/examples/PiezoAcoustic/PiezoAcoustic.pdf|Modeling of Piezoelectric and Acoustic Elements with LTspice\SwCad 
]]       and        {{appendix_c.pdf?linkonly|mirror}} (PDF)
  * [[http://www.brl.uiuc.edu/Downloads/bigelow/APPENDIX%20C.PDF|THE RLC CIRCUIT MODEL FOR A PIEZOELECTRIC
TRANSDUCER]] and {{piezoacoustic.pdf?linkonly|mirror}} (PDF)

{{ https://i.imgur.com/7kt8khR.png }}

=== source ===
{{https://github.com/5shekel/ledB|github}}