Hello,
Maybe some people on here will be able to answer this:
I'm looking to construct a Simple Speaker Protection Circuit using 2 x Back to Back Electrolytic Capacitors. To get reasonable Low frequency Response using a 12" 8 Ohm Driver, - (looking at commercial designs) - I assume that I will be needing a Capacitance Value of at least 2-3000 Microfarads to go in series with the Speaker Output. My Power Amplifiers run 60 volt Plus and Minus Rails, so I was thinking that 2 x 6800uF Capacitors connected Back to Back with a Voltage Rating of 40 Volts would be adequate. Somewhere else suggested using a Diode connected across each capacitor, with the + of the diode connected to the + of each capacitor would work better, to do with keeping each capacitor formed. At the moment, You cannot get Bi-Polar Caps with more than 2,200 uF at 25 Volts.
Here, I'm trying to get away from the idea of Isolation Relays or Series Forward Biassed Power Fets, because all of this can still fail. I'm looking to transfer no more than 50Watts of RMS Power, the rating of the drivers.
I'm sure that with everyone's vast experience on here, someone will know the answer! Thanks, and Kindest Regards - Telnet100
Maybe some people on here will be able to answer this:
I'm looking to construct a Simple Speaker Protection Circuit using 2 x Back to Back Electrolytic Capacitors. To get reasonable Low frequency Response using a 12" 8 Ohm Driver, - (looking at commercial designs) - I assume that I will be needing a Capacitance Value of at least 2-3000 Microfarads to go in series with the Speaker Output. My Power Amplifiers run 60 volt Plus and Minus Rails, so I was thinking that 2 x 6800uF Capacitors connected Back to Back with a Voltage Rating of 40 Volts would be adequate. Somewhere else suggested using a Diode connected across each capacitor, with the + of the diode connected to the + of each capacitor would work better, to do with keeping each capacitor formed. At the moment, You cannot get Bi-Polar Caps with more than 2,200 uF at 25 Volts.
Here, I'm trying to get away from the idea of Isolation Relays or Series Forward Biassed Power Fets, because all of this can still fail. I'm looking to transfer no more than 50Watts of RMS Power, the rating of the drivers.
I'm sure that with everyone's vast experience on here, someone will know the answer! Thanks, and Kindest Regards - Telnet100
Worst case, you have 60V across the cap. And if you do not notice the failure and leave the amp on, for significant time, so 10%-25% safety factor.
A Twelve won't do much below 50Hz but we can't put the -3dB point there. Say 2 octaves down for -0.25dB and "some" damping factor. 12Hz, which rounds to 2,000uFd. So a safe plan would be two 4,000uFd 66V-75V. Per channel. Diodes not needed.
It has been asserted that electrolytic caps back-to-back, the opposing cap is a short on each half-cycle. That gives two 2,000uFd still 66V-75V.
A Twelve won't do much below 50Hz but we can't put the -3dB point there. Say 2 octaves down for -0.25dB and "some" damping factor. 12Hz, which rounds to 2,000uFd. So a safe plan would be two 4,000uFd 66V-75V. Per channel. Diodes not needed.
It has been asserted that electrolytic caps back-to-back, the opposing cap is a short on each half-cycle. That gives two 2,000uFd still 66V-75V.
Hello
Thank you so much! So what You are suggesting, is that If I up the Voltage Rating to the next commercial size, which is 63 Volts, we should be fine? Actually that 60 volts was only nominal; What I actually measure is + and - 58 Volts at idle.
So the Diodes are not necessary/waste of time?
Thanks for all; I had read many differing opinions on this.
Kindest Regards - Telnet100
Thank you so much! So what You are suggesting, is that If I up the Voltage Rating to the next commercial size, which is 63 Volts, we should be fine? Actually that 60 volts was only nominal; What I actually measure is + and - 58 Volts at idle.
So the Diodes are not necessary/waste of time?
Thanks for all; I had read many differing opinions on this.
Kindest Regards - Telnet100