| Electronics > Beginners |
| MOSFET turned off - strange voltage drop |
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| tester43:
Hi, My Mosfet is handling AC unfiltered half_waves. When it's on - everything is perfect on my scope. On the place marked in schematics (see right side of schematics, drain) I see perfect half waves from 0 to 12V as expected when mosfet is closed (conducts current through load resistor). The issue I have is: when gate of Mosfet is not charged (mosfet not conducting) I see waves with 0 shifted to 0.7-0.8V (approx.). Probing between zener and it's resistor is visible as attached. I do not see any reason to have this voltage at the place... what can it be? |
| T3sl4co1l:
Put a pulldown resistor across the FWB output. Tim |
| tester43:
Hi Tim, Thank you for super quick answer, it's around midnight at my place :) But.... as stupid as it might sound but... what is FWB? |
| T3sl4co1l:
Full Wave Bridge [Rectifier] |
| tester43:
Hmmmm.... How would it work.... Are you saying to put a resistor between + and - of FWB? Or do I get it wrong. Putting a resistor between + and - would put a resistor parallel to mosfet and LOAD resistor.... Do you have any idea what is this 0,8 that I see on scope? |
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