eighty dollar dip SSR

Maybe Martin Shkreli is in charge over at Teledyne.

Cheers

I may as well make my own SSR from a PV coupler and a couple of self-protecting mosfets. More board area but 1/20 the price.

huh,

GH

Den tirsdag den 27. juni 2017 kl. 22.31.12 UTC+2 skrev John Larkin:

at one point we needed an SSR fast enough (~1ms) to short circuit protect a board full of triacs and capable of ~10A, the only one we found was a big potted block and afair several 100 dollars

in the end two back to back fets and an isolated gate driver did the job

It's self-protecting, but so are the cheap Ixys parts. I wish people would make higher-current self-protecting SSRs; we'll probably make our own.

So why aren't there more fast, protected SSRs around? They could be SIPs or something, like the cheap dc/dc converters.

I prefer relays, nice isolation... and they have 'infinite' gain >:-} ...Jim Thompson

Only latching relays have infinite power gain.

Who makes self-protecting electromechanical relays?

You could probably get a bit current out of it if you cool it with this $20 fan:

Just the right size.

--sp

I use a part the same size to make logic level SSRs, and they are good to 50 mA, tops!

Jon

Here's an 8 amp SOT23

This one

switching DC.

I wonder if a 2.5A polyfuse would protect it well enough.

--sp

We were thinking of a couple of something like this

back-to-back. Then we'd need an isolated gate driver. I think all that protection junk is powered by the gate drive, so the usual PV opto gate driver wouldn't be able to drive the pair. These things need a lot of gate current, like 400 uA.

Maybe a cheap DRQ74 type 1:1 transformer with high frequency drive, and a rectifier on the mosfet gate side?

Hard to believe they want 80 bucks for a protected FET (like the NCV8402) with a built-in photo isolator.

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That's out of their military systems/aerospace division. Everything they ma ke is top dollar. The products are usually high reliability and have extend ed environmental operational range. There was some scandal in the 80s with them cheating the government on the testing.

The military-industrial complex cheating the governmental-military complex?

Oh...my...God...

Should work well. There's no reverse current protection though.

--sp

Thereby providing yet another illustration that "private enterprise => good" and "government socialism => bad".

Or not, depending on the colour of your spectacles.