| Electronics > Projects, Designs, and Technical Stuff |
| Preventing ringing in audio mute circuit |
| << < (3/4) > >> |
| dmills:
Charge injection? Place a honking great cap across each of the the LEDs so it fades up and down rather then snapping on or off, and switch LED 2 on before switching led 1 off and vice versa. Regards, Dan. |
| David Hess:
It is not clear what is happening so the first thing I would try is AC coupling the optocoupler output and placing a resistor across the optocoupler output so that the capacitor remains charged to the average DC voltage. |
| Audioguru:
I made background music circuits for speakerphones. To prevent switching the music off at the peak voltage of the signal (causing a loud POP) I slowly ramped on the Jfet used for muting. I don't know if an optocoupler can slowly ramp on. An old fashioned LDR turns on fairly slowly and might work better. |
| cvanc:
Just trigger one switch at a time to see if it's only one opto that's causing the issue? And yeah, maybe stagger the trigger so the shunt element turns on first. |
| Psi:
I had time today to look into the issue a bit more. The DC offset idea is defiantly part of the problem, just need to figure out why there's DC where they should not be. --- Quote from: cvanc on March 23, 2019, 04:58:55 pm ---Just trigger one switch at a time to see if it's only one opto that's causing the issue? And yeah, maybe stagger the trigger so the shunt element turns on first. --- End quote --- It's the Mute opto that's causing the pop --- Quote from: Audioguru on March 23, 2019, 04:45:10 pm ---I made background music circuits for speakerphones. To prevent switching the music off at the peak voltage of the signal (causing a loud POP) I slowly ramped on the Jfet used for muting. I don't know if an optocoupler can slowly ramp on. An old fashioned LDR turns on fairly slowly and might work better. --- End quote --- Yeah, i may have to do that. Even with the DC removed i still get a small pop if changing between mute and a peak in the audio. |
| Navigation |
| Message Index |
| Next page |
| Previous page |