Optical coupling electrocardiogram measuring instrument

Optocoupler devices are widely used in electrocardiographs
, and a typical circuit is shown in Figure 5-29.
    Pins ① and ⑥ in the circle should be connected to the positive side;
pins ② and ⑤ should be connected to the negative side. Don’t make a mistake. As can be seen from Figure 5-29
, the left side of the dotted line is the control loop, and the signal
is input to the light-emitting tubes of pins ③ and ④; after the photosensitive tubes of pins ① and ⑦
receive light, the output signal is
input Operational amplifier, this feedback signal is helpful for the linearity of the linear
optocoupler
The right side of the dotted line is the main circuit of the circuit.
The light signal emitted by the light-emitting tube is
received by the ①, ②, @, and ⑥ pins. The output signals of pins ⑤ and ⑥ are amplified by operation.
After amplification, it is output, which controls the subsequent circuit.
    Linear optocoupler devices have been successfully used in electrocardiographs and are gradually being used in converters and other instruments .