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In the PI which has common supply for Hamerhead, Stuart1 & 2 does the opamps supply deviate during Tx on ?? and doe the speaker coil flyback interfer and feeed into upply and did this effect the circuitry...did any one measure with ocilloscope !!! by how much they deviate....
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Hi,Originally posted by sharky View Post
in PI detectors is normal having voltage rail fluctuations during heavy TX pulse phase.
Normally a tank capacitor is used to store part of the energy required during TX pulse for suppling current to the coil.
The size of the tank capacitor must suit the current required , so need to be tailored for that (read the Hammerhead pdf... to understand how and get an idea).
The speaker coil too could interfere with supply of op. amps. , often you have a filter at each op. amp. supply rail (positive and negative) to overcome that problem and other supply related noise (voltage converter etc).
Often to avoid speaker interference a separate rail supply the audio section and audio stage is driven by optical devices (optocouplers).
Absolute values of ripples etc have no great meaning there... you just need minimize unwanted effects.
Best regards,
Max -
Dear Max
I know about the storage caps at supply rails of opamps, but I need to know the values of the voltage fluctuations at Tx on and also the flyback noise due to speaker coils with actual scope measurements (not simulation) as I dont have access to oscilloscope as I am shifting to some other companyComment
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