The datasheet does not actually say. Where is the anode/cathode for these To-200AB packages?
http://www.vishay.com/thyristors/list/product-94396/
http://www.vishay.com/thyristors/list/product-94396/
I'm guessing an SCR that big wouldn't be harmed by the voltage from a 12V transformer or the current to light a car indicator bulb.No the bottom is the Anode in the pic normally.
Max.
Thats interesting, it won't work unless I physically clamp it down with a screw..? I assume the hole in the center goes right through it then. If anyone knows where to buy custom heat sinks for these To-200AB packages please post. Something like below does not have a hole in the center to bolt it to the SCR so I have no idea how to properly clamp it.As a side note, please be advised that proper (mechanical) 'clamping' is essential to device operation and integrity and not merely for heat-sink efficiency! It seems the construction 'expects' a precise compressive force (should be found in the Specs) --- Indeed many such units will test (electrically) open while 'uncompressed'...
HP
It may or may not test OK out of compression, however it will not be reliable...Thats interesting, it won't work unless I physically clamp it down
I very much doubt it -- I've not encountered a device designed to be clamped via a transfixing fastener...I assume the hole in the center goes right through it then.
You'll probably want to start with a significant block of aluminium for the heatsink, tap 2 or 4 lengths of studding to stick up vertically beside/around the puck.Thats interesting, it won't work unless I physically clamp it down with a screw..? I assume the hole in the center goes right through it then. If anyone knows where to buy custom heat sinks for these To-200AB packages please post. Something like below does not have a hole in the center to bolt it to the SCR so I have no idea how to properly clamp it.
http://www.digikey.ca/product-search/en?x=4&y=22&lang=en&site=ca&KeyWords=882-200AB
FWIW said compression is required to establish/maintain internal connection --- I've not researched the rationale behind such design...I am intrigued. Why will this device not work reliably unless it has pressure applied?
Thanks
It seems unlikely that there isn't some form of bonding on the internal junctions, but I'm guessing that there will be some flexing of the mounting plate faces when its correctly torqued down, that would be taken into account in design and manufacture - that tiny bit of flexing has to be there for it to reach its full peak current spec.FWIW said compression is required to establish/maintain internal connection --- I've not researched the rational behind such design...
Best regards
HP
FWIW In my own experience new devices (directly sourced from reputable distributors) often test 'open' (~30% incidence) sans a (minimum) compressive force of 50kg - 100kg -- Curious indeed...It seems unlikely that there isn't some form of bonding on the internal junctions, but I'm guessing that there will be some flexing of the mounting plate faces when its correctly torqued down, that would be taken into account in design and manufacture
Once I worked for a firm that used those press-fit rectifiers like the ones in car alternators.FWIW In my own experience new devices (directly sourced from reputable distributors) often test 'open' (~30% incidence) sans a (minimum) compressive force of 50kg - 100kg -- Curious indeed...
Best regards
HP
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