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Soft as a Feather Pillow (SFP) SSR Soft Start Circuit GB

Thanks
When I looked at Octopart, for some reason it only showed Mouser, Digikey and TI. I went to the TI site, but it wouldn't let me order parts there.

The Newark stock is in England, and RS is in England too.

So my current, somewhat bold plan, is to buy SM parts, and with some bending and little wires, install them in the board. I'll ordering a few to allow for mishaps. Not for the faint of heart, but I've done a fair amount of SM soldering and hacking stuff up, so I think I can do it.

Randy
 
Thanks
When I looked at Octopart, for some reason it only showed Mouser, Digikey and TI. I went to the TI site, but it wouldn't let me order parts there.

The Newark stock is in England, and RS is in England too.

So my current, somewhat bold plan, is to buy SM parts, and with some bending and little wires, install them in the board. I'll ordering a few to allow for mishaps. Not for the faint of heart, but I've done a fair amount of SM soldering and hacking stuff up, so I think I can do it.

Randy
Click "Show All" under the list of distributors
 
It was strange, when I tried TI the first time, it would let me add them to the cart, tried again, and it was fine.
But in both cases, adding shipping made it kind of expensive for one part.

I looked for subs and found that the LM393 is basically the same part, its in the same TI datasheet. LM393p is a 0 to 70C temp part where the LM2903 is -40 to 125C. I don't expect my amps to get that hot, 70C should be more then enough so I ordered a LM393.

Randy
 
Looks like maybe the LM293 could work as well. X, can you confirm?

It looks like maybe the 393 is the "standard" operating temperature version, 293 is the "extended" temps version, and 2903 is the "extreme" temps? I'm not sure if that's the only difference though.

Series datasheet: https://www.ti.com/lit/ds/symlink/l...l-mousermode-dsf-pf-null-wwe&ts=1644256495254

How much does AVD (Large-signal differential-voltage amplification) matter? I see there's a slight difference between LM293/393 and LM2903 in that parameter.
 
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I think we are ready to start a list of interest for this PCB. They will be 1.6mm thick with 2oz copper and ENIG finish. Price will be $23. Shipping will be the usual as determined by Etsy for USPS First Class package with tracking.

Please add your name to the running list below with number of boards and country.

SFP GB Interest List

For example:

Johndoe 2 boards USA
precisionav Jim 1 board USA
 
Ahh cool thanks, I figured I didn't have the correct industry terms. What temp class would the 293 (−25 to 85°C) be called?
From my experience, commercial is 0-70c and mil is -55 to 125c, and this is generally accepted. So I guess I was a little off in calling the 2903 as mil spec.

Industrial temp can vary, the most common value I see for industrial is -40 to 85C. But its not as standardized as the two above, so I'd still call -25 to 85c industrial. Its sort of a catch all for anything between commercial and mil spec.

Looking at the data sheet again, in the family comparison table on the first page, the LM193 is truly mil temp.

Seems like the aimed for my definition of industrial for the LM393B, but not sure what they were going for with the LM2903B.

Randy
 
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Hello X,

Can you confirm one thing? I'm in Brazil and my Power Outlet gives me two lines without a neutral (-120V / +120V AC, for a total of 220VAC effective) the right way to implement this in a amp here would require 2 boards?
Thanks
Gabriel
 
Is there anything else I can substitute for U2, the TLP3905(TPL,E ?

I checked Octopart and it looks like it's out of stock everywhere until March of next year :-(

U1 (IRM-02-5, the Meanwell 5V DC supply) is also out of stock on Mouser till October…debating whether to wait for it to ship till then or pay an extra $12+ to get it now from somewhere else
 
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