Bad Full-wave Recitifier
This circuit is one of AutoTrax software examples. It shows a bad connection that should not be recreated in real life.
The high voltage difference between two oscilloscope terminals could be well above the maximum specified limits. Thus the oscilloscope will fail with a bang.
Bad EEG Pre-amplifier
This EEG pre-amplifier is made to amplify very low signals from human brain. The problems with this circuits include:
1. 741 is a general purpose operational amplifier. High precision Op-Amps/instrumentation amplifiers with low noise levels should be used (eg. INA101).
2. The resistors are not matched. 1% will not be enough the create the very high amplifier common mode rejection ratio (CMRR) that is needed for medical instrumentation.
3. The pre-amplifier is not isolated with an opto-coupler. A power surge can electrocute the user.
1. 741 is a general purpose operational amplifier. High precision Op-Amps/instrumentation amplifiers with low noise levels should be used (eg. INA101).
2. The resistors are not matched. 1% will not be enough the create the very high amplifier common mode rejection ratio (CMRR) that is needed for medical instrumentation.
3. The pre-amplifier is not isolated with an opto-coupler. A power surge can electrocute the user.