Although the input of this mosfet amp module is DC coupled, I wounder why an amplified pure positive input signal is still positive and negative at the output?
Does this come from the type of bias circuit (please have a quick look at the schematics) and that this is class AB amp? Does perhabs somebody know if there is a easy way to preserve the DC offset? Maybe with class B biasing?
-- I'm new to mosfet amps, and probably that is the typical function of a mosfet amp, so please let me know if it's not possible to amplify a positive only signal with mosfets.
TIA
Oscilloscope image: CH1 (red input) 500mV /1 DC, CH2 (yellow output) 10V /10 DC, time 200us:
Schematics: Cin shorted
Does this come from the type of bias circuit (please have a quick look at the schematics) and that this is class AB amp? Does perhabs somebody know if there is a easy way to preserve the DC offset? Maybe with class B biasing?
-- I'm new to mosfet amps, and probably that is the typical function of a mosfet amp, so please let me know if it's not possible to amplify a positive only signal with mosfets.
TIA
Oscilloscope image: CH1 (red input) 500mV /1 DC, CH2 (yellow output) 10V /10 DC, time 200us:
Schematics: Cin shorted
Attachments
Last edited:
You have shown an AC coupled amplifier.
If built properly this will not amply DC signals and will not pass an input DC to the output.
If you want/need to amplify DC input signals then you need a DC coupled amplifier.
Then you will have to learn how to keep that amplified DC as an accurate, but scaled, copy of the input signal.
If built properly this will not amply DC signals and will not pass an input DC to the output.
If you want/need to amplify DC input signals then you need a DC coupled amplifier.
Then you will have to learn how to keep that amplified DC as an accurate, but scaled, copy of the input signal.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.