Mike Hanson
Trying to understand...
I hunted for them for a while, sent repeated emails, tried to find a suitable replacement transformer myself, etc. I finally got fed up and moved on.
Point taken, but who switches a power amp off when there is signal present?
Things I would wish for in a speaker protection design
- Amp switch on delay as there is often a DC thump at switch on
- DC speaker protection monitoring on the output
- Amplifier Oscillation would trip the output to the speakers, the velemans picked up a faulty interconnect (disconnected ground) once at a bake off and my amp refused to switch on showing a red light.
- Good heavy duty speaker connections in and out
- 30A relays
Alan
My files above updated.
I have added 6.35mm Faston connections.
Do I need resistors to ground on the amplifier side to charge output capacitors?
It would be easy to give an extra long switch on thump delay option for amplifiers with these.
Hi,My simmed unit is now about as far as I want to take it for now. Super fast reacting due to multiple order LPF, turn on delay for thumps and while it checks for DC offset, combination of mosfets and gold plated contact relays in phased switching arrangement so relay never switches or sees DC or in fact much in the way of anything.... it's there to short out any possible "sound of mosfets/silicon". Under actual fault condition another layer of protection comes in and removes power from the amplifier itself leaving it "in protect" and needing a reset by removing mains. Spare OR'ed inputs present for HF detection, over temp, and even the driver protection by frequency band. No SMD parts or any specialised ones available from just one company. Sorted and ready to be abandoned like the hundreds of other designs
Hi,
Why not publish the design, and let others pursue the PCB design if they want to ?.
You could do a group buy if you designed the PCB yourself, or offer the unit in the classifieds as a final solution with notes.
There have been quite a few enquiries here in the DIY section on the amplifier/loudspeaker protection circuit, whether the IC that is difficult to locate, or the Velleman kit. Another source where it is easier to discuss the solution from the designer may be preferred.
Regards,
Shadders.