This configuration appears at several points in this section, obtained from different sources. This is from American documentation. The gain is 20 and the transistor can be a BC549.
This digital circuit is from a Radio Electronics magazine from December 1991. It does not use a...
This circuit is an isolated shield for microcontrollers such as the Arduino, MSP430, PIC and...
August 2017 - This Maxim component, available from Mouser Electronics, is ideal for wearables,...