It sounded like the police had some good information to go by so my fingers are crossed that some form of justice will be served.
I won't be goaltending for a bit. My left shoulder definitely won't appreciate that. I might show up and skate warmup with my Sunday hockey. We'll see. I'll play it safe. Concussions are not fun. I don't feel too bad in that regard. I got about 3.5 hours of good sleep last night, so sleep deprivation is a factor too. I'm not walking into stationary objects like I did last I bumped my head.
And thank you for your well-wishes and recommendations. The ER doc recommended acetaminophen + ibuprofen.
Tom
I won't be goaltending for a bit. My left shoulder definitely won't appreciate that. I might show up and skate warmup with my Sunday hockey. We'll see. I'll play it safe. Concussions are not fun. I don't feel too bad in that regard. I got about 3.5 hours of good sleep last night, so sleep deprivation is a factor too. I'm not walking into stationary objects like I did last I bumped my head.
And thank you for your well-wishes and recommendations. The ER doc recommended acetaminophen + ibuprofen.
Tom
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Yikes, Tom. That sucks, but very fortunate that it was not worse. Hope you’re feeling better and stronger soon. Be prepared for and open to extended physical therapy for your muscular injuries. I had a similar experience several years ago and the involuntary tensing up just before impact led to multiple problems with my back. Dedicated physical therapy brought me out of that. Be patient with your healing.
I'll definitely need some physiotherapy. I've started with some acupuncture and massage just to get things moving a bit but that has set off an avalanche of muscle tightness. Fun, fun. Happy, happy. At least my brain seems mostly intact. There's no doubt I have a concussion. I've lost my sense of time. It's really weird. And I'm definitely more irritable than normal, though that could be because of all the muscle crap too. A friend of mine has had several strokes and now we get to compare brain damage. It makes for some fun conversations.
Getting back to the Guardian-86, however: There's a clear tradeoff between the reaction time of any protection circuit and the amount of protection offered. It's analogous to fusing. A fuse should blow to prevent your house from burning down. It shouldn't blow because you crank the volume knob past 3 o'clock.
Same with the Guardian-86. It should interrupt current flow to the speaker when "excessive" "DC" is present. The questions are then, what is "excessive" and what is "DC". I think most would find it pretty annoying if the speaker protection circuit turned the music off at each heavy bass thump, so I designed the Guardian-86 to allow for a rail-to-rail 20 Hz signal to pass (assuming ±100 V rails). Some may consider this excessive. I certainly would if I was designing a headphone amp, which is also why I don't recommend the Guardian-86 for headphone amps.
Most importantly, the protection circuit should interrupt the flow of current quickly once it is determined that such action is necessary. MOSFET switches do this nicely. Relays not so much. I'd love to be able to repeat the experiment shown here: https://www.halfgaar.net/dc-protection-with-relays with the Guardian-86. I think that would make a great video. Right now my priorities are to get my brain back in order, search for a replacement car, and prepare for Axpona. Because in a one-man business there's no such thing as slowing down. 🙂
Tom
Getting back to the Guardian-86, however: There's a clear tradeoff between the reaction time of any protection circuit and the amount of protection offered. It's analogous to fusing. A fuse should blow to prevent your house from burning down. It shouldn't blow because you crank the volume knob past 3 o'clock.
Same with the Guardian-86. It should interrupt current flow to the speaker when "excessive" "DC" is present. The questions are then, what is "excessive" and what is "DC". I think most would find it pretty annoying if the speaker protection circuit turned the music off at each heavy bass thump, so I designed the Guardian-86 to allow for a rail-to-rail 20 Hz signal to pass (assuming ±100 V rails). Some may consider this excessive. I certainly would if I was designing a headphone amp, which is also why I don't recommend the Guardian-86 for headphone amps.
Most importantly, the protection circuit should interrupt the flow of current quickly once it is determined that such action is necessary. MOSFET switches do this nicely. Relays not so much. I'd love to be able to repeat the experiment shown here: https://www.halfgaar.net/dc-protection-with-relays with the Guardian-86. I think that would make a great video. Right now my priorities are to get my brain back in order, search for a replacement car, and prepare for Axpona. Because in a one-man business there's no such thing as slowing down. 🙂
Tom
Natural experiment and real test. This is what we need. We'll be waiting for your video.
Who's "we"?
I have already committed to making the video, but as I've told you here and on my own forum, I'm currently recovering from a pretty serious car accident that has left me with a concussion. I also have Axpona coming up and will turn that into a trip. Furthermore, I'm way behind on two consulting projects. My clients pay me way more that you do, so they get priority. Sorry buddy. That's reality.
Tom
I have already committed to making the video, but as I've told you here and on my own forum, I'm currently recovering from a pretty serious car accident that has left me with a concussion. I also have Axpona coming up and will turn that into a trip. Furthermore, I'm way behind on two consulting projects. My clients pay me way more that you do, so they get priority. Sorry buddy. That's reality.
Tom
I expect Konrad’s comment was more along the lines of positive anticipation, more like “That’s great! It will greatly contribute to the forum and we look forward to it.”
Good luck with getting caught up with things as you recover, Tom. The diyAudio “we” wish you well.
Good luck with getting caught up with things as you recover, Tom. The diyAudio “we” wish you well.
I don't respond well to nagging. It's not just here that he's asking for this and I've already committed to shooting the video. But like anything else I do, I prefer to do it well.
Tom
Tom
SQJQ410EL has parameter Input Capacitance Ciss = 5620...7350 pF
If you use a MOSFET with a lower Ciss , will it turn off the speakers faster?
Does this setting affect the shutdown speed?
If you use a MOSFET with a lower Ciss , will it turn off the speakers faster?
Does this setting affect the shutdown speed?
Is there any drawback to putting these in a box separate from the amp? I keep building more amps and it would be a big savings in the end to just have one really good speaker protection system.
If you synchronize the power supply to the Guardian-86 with the supply in the amp you won't see any major drawbacks. If you keep the Guardian-86/686 powered constantly you lose the turn-on/off pop protection but you still get protection against excessive DC voltage.
Tom
Tom
Perfect. I've got one of those outlet strips that sense the amp turning on and switches the DAC on so I can plug it in there.. I'd be gutted if an amp I built killed our speakers.
Oop. I have to walk that back half a step. If you want full protection you need to provide the Guardian with the same power supply as the amp.
If you synchronize the power supplies as you describe you should get protection against turn-on plops but possibly not against turn-off plops. That all depends on whether the power supply for the Guardian-86 drops out before the supply in the amp.
If you use a 12 V SMPS wall wart to power the Guardian-86, I'd add a resistive load across the power supply. I'd go for something like 470 Ω, 1 W. The SMPSes usually take a second or two to start up so you will have turn-on plop protection and the 470 Ω should discharge the supply fast enough that the supply for the Guardian-86 drops out before the supply to the amp.
In all cases you'll have protection against excessive DC voltage.
Above applies to Guardian-86 Rev. 2.0. Guardian-86 Rev. 1.0 and Guardian-686 will work at a very low supply voltage, so you may not get turn-off plop protection with those. You'll still get turn-on protection if the SMPS starts up after the supply in the amp and you will get protection against excessive DC voltage.
Keep in mind that the Guardian-86 is intended to be powered by the power supply in the amp. Doing so avoids all these "what-ifs".
Tom
If you synchronize the power supplies as you describe you should get protection against turn-on plops but possibly not against turn-off plops. That all depends on whether the power supply for the Guardian-86 drops out before the supply in the amp.
If you use a 12 V SMPS wall wart to power the Guardian-86, I'd add a resistive load across the power supply. I'd go for something like 470 Ω, 1 W. The SMPSes usually take a second or two to start up so you will have turn-on plop protection and the 470 Ω should discharge the supply fast enough that the supply for the Guardian-86 drops out before the supply to the amp.
In all cases you'll have protection against excessive DC voltage.
Above applies to Guardian-86 Rev. 2.0. Guardian-86 Rev. 1.0 and Guardian-686 will work at a very low supply voltage, so you may not get turn-off plop protection with those. You'll still get turn-on protection if the SMPS starts up after the supply in the amp and you will get protection against excessive DC voltage.
Keep in mind that the Guardian-86 is intended to be powered by the power supply in the amp. Doing so avoids all these "what-ifs".
Tom