sdp_sense_scaler_2 PUBLIC

Not provided.

This one uses a LF353 JFET dual-input op-amp to scale the signal down. First an inverting amplifier reduces it to -16.5mV, and then another inverting amplifer inverts the signal. The pacemaker approves, although the spikes are huge. If I use a 200ohm resistor instead of a 330ohm for the first, it still works but I need to change the sensitivity to 1mV for the pacemaker to register the input. This circuit works fine with 10mV sensitivity. The use of 2 9V batteries probably gives a much cleaner supply voltage than the power supply.