This high impedance step suggested by an English publication can operate up to 1 MHz with 1 V rms output. Input impedance is 1 M ohm.
This circuit was obtained from a 1967 General Electric manual. The circuit uses components of the time,...
This Radio Electronics circuit, in an 80's edition, decodes the 67 kHz signal used at the time to...
August 2016 - It can be obtained from Mouser Electronics the battery protectors series bq7790x of...