The max DC blocking is limited to the three TO220 diodes in series, or 3x 0.6v for 1.8vdc max.
One of the tests we used to do on new designs when I worked for DEC was AC line transient testing. I remember being recruited to operate some Schaffner generator, which would put ~4kV in differential and common mode. I had run the test before and always thought "this doesnt do anything". Then one day it did - nearly knocked me out of the chair by the bang that came out of the power supply.
The etch design had some pattern about a screw holding the PCB to the chassis. That pattern ended up looking like two points, aimed at one of the AC line traces running past. Apparently the field at the point tips became too intense as it arced over with a bang. They fixed it in the next etch spin.
Unsure if such testing is applicable to your AC line connected product, relative to something like a power supply for a VAX computer. I guess someone at DEC used to think such AC line transients really did happen out in the field and wanted the product to be impervious to it. Of course, back then they did lots of crazy testing - like SPRT estimation of MTBF - that no one these days can afford.
The etch design had some pattern about a screw holding the PCB to the chassis. That pattern ended up looking like two points, aimed at one of the AC line traces running past. Apparently the field at the point tips became too intense as it arced over with a bang. They fixed it in the next etch spin.
Unsure if such testing is applicable to your AC line connected product, relative to something like a power supply for a VAX computer. I guess someone at DEC used to think such AC line transients really did happen out in the field and wanted the product to be impervious to it. Of course, back then they did lots of crazy testing - like SPRT estimation of MTBF - that no one these days can afford.
That's just a temporary chassis for set up and testing it'll get moved to two single cases.
That’s white silicone RTV used to mechanically stabilize parts to reduce mechanical stress on the larger parts. This was applied at the factory where production takes place.
On the bench is a 3D printed test panel to check fitment of IEC inlet shells and NEMA outlet plugs for a couple of new products: SnubStation Zero and InfinityFuse.
We initially had snap in receptacles but they felt iffy. I much prefer screw mounted sockets for secure hold.
We initially had snap in receptacles but they felt iffy. I much prefer screw mounted sockets for secure hold.
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Hi Viet,
You probably missed my question in the other thread, so I'll repeat it here if I may:
What is the current consumption of the HyperSET (@230vac)? Just asking, because I would like to place the "final" fuse into the amp.
Now I use 2,5A because of the PSU, but maybe it's to much.
Many thanks in advance.
Cheers
Istvan
You probably missed my question in the other thread, so I'll repeat it here if I may:
What is the current consumption of the HyperSET (@230vac)? Just asking, because I would like to place the "final" fuse into the amp.
Now I use 2,5A because of the PSU, but maybe it's to much.
Many thanks in advance.
Cheers
Istvan
Sorry I missed the message Istvan.
I just performed a field test using a wall plug “wattometer” of a HyperSET with J&J E88CC tubes. 160mA peak at turn on and 110mA steady state at 120VAC. So about half that at 230VAC. This is using a SMPS AC/DC wallwart power adapter for the 12v.
So you need a tiny fuse of say 1.3x 80mA or circa 0.1A fuse should work. Might want a slow blow to prevent turn on transient from blowing it. Probably 0.2A fuse would be fine as well.
I just performed a field test using a wall plug “wattometer” of a HyperSET with J&J E88CC tubes. 160mA peak at turn on and 110mA steady state at 120VAC. So about half that at 230VAC. This is using a SMPS AC/DC wallwart power adapter for the 12v.
So you need a tiny fuse of say 1.3x 80mA or circa 0.1A fuse should work. Might want a slow blow to prevent turn on transient from blowing it. Probably 0.2A fuse would be fine as well.
Msny thanks Viet!
Now I just have to add tho consumption of the input selector relais, LEDs and that of the remote control unit.
Now I just have to add tho consumption of the input selector relais, LEDs and that of the remote control unit.
@xrk971 Overall, the LM3886 is my third project that I "finished" per say... do we ever actually finish those?
I started it all with a PAM board, it was pretty bad overall, then I got a TPA3116 and delved deep into it, I still have my dual 3116 with your Snubber mod (been some years!)
There was also a TDA7377 which my FIL is currently using, and lastly this 3886. It took me a while to find a housing that would fit everything inside, aluminum chassis are pretty expensive where I live!
I ended up going with that board because it was the only one that somewhat resembled the boards made by Neurochrome. It really doesn't sound bad and it packs quite a bit of power considering I only feed it with 21-0-21v (that's the V output of that PSU).
I started it all with a PAM board, it was pretty bad overall, then I got a TPA3116 and delved deep into it, I still have my dual 3116 with your Snubber mod (been some years!)
There was also a TDA7377 which my FIL is currently using, and lastly this 3886. It took me a while to find a housing that would fit everything inside, aluminum chassis are pretty expensive where I live!
I ended up going with that board because it was the only one that somewhat resembled the boards made by Neurochrome. It really doesn't sound bad and it packs quite a bit of power considering I only feed it with 21-0-21v (that's the V output of that PSU).
Lots of very tedious wiring. Total of 48 tweeters connected to 12 amplifiers and 28 woofers connected to 7 amplifiers.
It's alive!. It's now on the software development bench, where it is working as a 3-way without the shading or curvature. I should be able to reuse most of the code from the previous line array design to implement the electronic curvature and shading. It also needs dipole compensation since this is open baffle. The second one for stereo is still on the hardware bench. Putting the electronics on a hinged plate is working out well for development.
That’s a way cool project, Neil. Congrats on first sound!
On the bench tonight is a new coaxial speaker development I am starting. It’s an OEM design with a polycone woofer and a small compression driver with a small horn. The woofer has a nice magnet and sounds very smooth. Tweeter has nice upper end reach. Cabinet has usual perfect rosewood veneer and a slot vent reflex. I’ll be making measurements and developing a new crossover soon. This will be fun to see if I can make a time aligned single point source.
There’s a magnetically attached grill.
On the bench tonight is a new coaxial speaker development I am starting. It’s an OEM design with a polycone woofer and a small compression driver with a small horn. The woofer has a nice magnet and sounds very smooth. Tweeter has nice upper end reach. Cabinet has usual perfect rosewood veneer and a slot vent reflex. I’ll be making measurements and developing a new crossover soon. This will be fun to see if I can make a time aligned single point source.
There’s a magnetically attached grill.