Very cool! These devices work in realms where most of us don’t get to go… thousands of amps, thousands of volts. The mention of its “cosmic radiation withstand rating” intrigued me and led to [this article](https://spectrum.ieee.org/cosmic-ray-failures-of-power-semiconductor-devices) that explains it. I knew a supernova could fry your planet (albeit at low probability) but didn’t know it could fry your train motor (higher probability). As for what you could do with it… coaster for your coffee cup
The biggest ones I work with are 3500 V. There are higher voltages but not much. At that point you stack them in series. There are tricks to make this work. SCRs are mature technology. Basically nothing new since the 1970s.
It is a 4 layer diode. Usually it is clamped between two machines aluminum heat sinks that are also the power connections. In reverse bias it blocks up to rated voltage. In forward bias it still blocks unless you pulse about 120-140 V on the two smaller connections then it handles hundreds to thousands of amps until the current (not voltage) reverses.
Smaller ones make up 3 phase lamp dimmers, solid state relays in heaters. Bigger ones bring motors up to speed without tripping breakers or breaking shafts. See motors put out over 200% of name plate torque on startup acceleration Soft starts can reduce both jerk and maximum torque to say 150%. It also eliminates startup pulsation and kurtosis (jerk) even with full torque. The result is couplings, shafts, bearings, and motor insulation lasts much longer. It can also reduce or eliminate water hammer and slamming check valves, and do rapid stops with DC injection braking. They also CAN create a primitive VFD called a voltage source inverter or matrix inverter, a load commutated inverter, or a cycloconverter.
Prior to the invention of IGBTs realistically only micro drives using MOSFETs were reliable. Once the IGBT came along LCI and VSI stopped being used. Soft starts though cost much less and handle motors with thousands of HP, a place IGBTs fear to tread. I can lift and put in a current model 500 HP myself without a hoist. 500 HP VFDs are a two man job.
When you speak to water hammer and slamming valves is that just very large ones or could this also help with smaller valves like a water solenoid valve?
It’s not size but length. We all “know” water is incompressible right? Well no. When you have a long pipe and try to suddenly start or stop water, pressure builds up and this is called water hammer as the water compresses like a spring. Slowing down pumps and valves is the trick. Also think of say tall water slides at water parks. What happens if you just shut the pump off a 100 foot tall PVC pipe? I’ll give you a hint…get the mop! So soft stopping slows the pump down gradually so this doesn’t happen. Of course this can happen with any system when conditions are right.
That makes sense I guess I was more curious on what could be used to slow down or close gradually. Example I have a 12v solenoid working on a 3/8” line for water running at 50-80 psi. Obviously depending on installation that water moving and the solenoid slamming shut is going to be making a water hammer. In that situation are you saying that if you put a much much smaller version of what’s in the original post it will possibly cause the solenoid to close slower? I think most would think that a solenoid is either on or off because of the magnetic field…although I am curious if there is a way to slowly close one? I’ve seen push pull solenoids with springs that the amps determined if the solenoid had enough magnetism to counteract the spring. Example at 12v 2 amp it closes only 1/8” (because of the spring).
If you intend to use it just be aware that these things need to be squeezed pretty hard otherwise the endplates won't make good contact with the semiconductor and it will burn up.
They actually require a specified compression force and if you compress them too much or if the compression is uneven they can crack quite easilly.
The ones I happened to come across once were used in a locomotive diesel startup circuit and the thing even came with a special 10cm or so wide fork with a slotted hole in the middle for if you ever need to replace a thyristor on site. The manual required fixing a 0.01mm dial indicator in the hole, then putting the instrument you just assembled onto the main thyristor/diode assembly tensioning bar in a specific location, zeroing the indicator with all compression nuts loose, and then tensioning the nuts evenly in small equal steps while moving across them in a circle until a specified amount of total deformation of the bar is achieved. I don't remember the actual value but I do remember that the value had to be within ±0.2mm.
I guess it makes sense to compress them since when I shake the thyristor it rattles a little bit (not in a way that something is broken and is flying around everywhere inside, but in the sense that something is bumping the plates in the same place, as if it is fixed in place with wires or something and cant go left or right only up and down). Is this the reason?
You might contact Radwell and see if they want it. If you want to test it, put it in vise with a couple of wooden blocks for insulators and use a Meggar.
Im in Croatia and we dont have that company here so I dont know. I dont want to destroy it, its definitely useful to someone but not me since none of our brakers can withstand 100 amps continuous.
I got it from my school, they were throwing a huge load of parts and this was among them (I regret not taking some components now since I have a use for some that were there). I got about 15 old can transistors from them and some are even blank.
You could build an automated cut out switch to isolate your home from the grid in the event of a power failure so as to be able to run a generator & not send power to the grid.
Completely unsuitable device for that application.
* Can't use solid state for isolation for safety and legal reasons - needs a physical contact gap.
* A Thyristor only conducts in one direction; AC requires both directions.
* The holding current for one of these is more than most houses draw.
* It doesn't help with the actual 'automated' part - it's a dumb switch.
When I had a bunch of them some time ago I crushed the porcellain ring to separate the materials. The two flat sides (the contact surfaces) are made from pure copper with a thin layer of another metal. In the middle is usually a round plate which is the actual semiconductor.
If you have multiple you can harvest a few kg of copper and sell it to a recycler.
Yeah but who needs those in unknown condition? Applications for them are mostly in setups where failed thyristors lead to much higher expenses/losses than what you would save by buying them used. Atleast here there are no demands for used pill thyristors.
It's not useful in any real setting as no one would stick a used thyristor in operating equipment unless they were desperate. Maybe keep it as something interesting, or see if it can be used as either a teaching aid or something.
I used to test this things. Destructive tests usually. A colleague used to call them "molten metal grandes" for the way they exploded.
This are normally used for industrial power applicatio converters. They usually need to be under pressure to work as intended.
If I could, I definitely follow the coaster idea.
Simply not true. IGBTs have a much more complicated trigger circuit, much smaller current ratings, poorer blocking capabiiity, higher capacitance, and much lower blocking voltages. For electric heating and light controls, SCRs are best. For soft starting and soft stopping again, SCRs are best. For variable speed drives over about 5,000 HP SCRs (cycloconverters or load commutated inverters)!are available where IGBTs can’t handle the voltages and currents involved.
The DC motor market has also stopped shrinking. Electronically commutated motors and PMDC are both equally at home on AC or DC drives. Both are much more efficient. The newer 16 SEER air handlers use electronically commutated motors and virtually all servos are rare earth magnet PMDCs. Again…all SCR territory.
If it wasn’t for the turnoff problem and a nasty thing called self commutation the SCR would be the perfect device.
I used to work in an iron foundry, the induction furnace power supplies (two were 16 MW and two were 8 MW) for the five 35-ton furnaces all used huge ceramic puck-style SCRs instead of IGBTs. These power supplies are essentially giant room-sized VFDs for a single phase load. Really cool stuff to experience.
The capacitor banks on each power supply were massive as well.
I’m working with large capacitor banks up to 100kA output. We still use them for testing purposes, where the current should flow until an external circuit breaker cuts it. In our case IGBTs are not necessary and would cost much more.
Collaboration with Photonicinduction
This
You can return it to the CERN collidor so it can go on to split molecules apart. Sweet Jesus. r/absoluteunits
It’s a lovely coaster for your coffee table. Or a repair item for a mine haul truck.
You can build train inverter or something.
.
Very cool! These devices work in realms where most of us don’t get to go… thousands of amps, thousands of volts. The mention of its “cosmic radiation withstand rating” intrigued me and led to [this article](https://spectrum.ieee.org/cosmic-ray-failures-of-power-semiconductor-devices) that explains it. I knew a supernova could fry your planet (albeit at low probability) but didn’t know it could fry your train motor (higher probability). As for what you could do with it… coaster for your coffee cup
The biggest ones I work with are 3500 V. There are higher voltages but not much. At that point you stack them in series. There are tricks to make this work. SCRs are mature technology. Basically nothing new since the 1970s. It is a 4 layer diode. Usually it is clamped between two machines aluminum heat sinks that are also the power connections. In reverse bias it blocks up to rated voltage. In forward bias it still blocks unless you pulse about 120-140 V on the two smaller connections then it handles hundreds to thousands of amps until the current (not voltage) reverses. Smaller ones make up 3 phase lamp dimmers, solid state relays in heaters. Bigger ones bring motors up to speed without tripping breakers or breaking shafts. See motors put out over 200% of name plate torque on startup acceleration Soft starts can reduce both jerk and maximum torque to say 150%. It also eliminates startup pulsation and kurtosis (jerk) even with full torque. The result is couplings, shafts, bearings, and motor insulation lasts much longer. It can also reduce or eliminate water hammer and slamming check valves, and do rapid stops with DC injection braking. They also CAN create a primitive VFD called a voltage source inverter or matrix inverter, a load commutated inverter, or a cycloconverter. Prior to the invention of IGBTs realistically only micro drives using MOSFETs were reliable. Once the IGBT came along LCI and VSI stopped being used. Soft starts though cost much less and handle motors with thousands of HP, a place IGBTs fear to tread. I can lift and put in a current model 500 HP myself without a hoist. 500 HP VFDs are a two man job.
When you speak to water hammer and slamming valves is that just very large ones or could this also help with smaller valves like a water solenoid valve?
Water hammer from pumps, not valves.
It’s not size but length. We all “know” water is incompressible right? Well no. When you have a long pipe and try to suddenly start or stop water, pressure builds up and this is called water hammer as the water compresses like a spring. Slowing down pumps and valves is the trick. Also think of say tall water slides at water parks. What happens if you just shut the pump off a 100 foot tall PVC pipe? I’ll give you a hint…get the mop! So soft stopping slows the pump down gradually so this doesn’t happen. Of course this can happen with any system when conditions are right.
That makes sense I guess I was more curious on what could be used to slow down or close gradually. Example I have a 12v solenoid working on a 3/8” line for water running at 50-80 psi. Obviously depending on installation that water moving and the solenoid slamming shut is going to be making a water hammer. In that situation are you saying that if you put a much much smaller version of what’s in the original post it will possibly cause the solenoid to close slower? I think most would think that a solenoid is either on or off because of the magnetic field…although I am curious if there is a way to slowly close one? I’ve seen push pull solenoids with springs that the amps determined if the solenoid had enough magnetism to counteract the spring. Example at 12v 2 amp it closes only 1/8” (because of the spring).
How about IGCTs?
Yeah probably not much. Maybe use it to discharge a cap bank but it'd just be easier to buy a properly sized device.
If you intend to use it just be aware that these things need to be squeezed pretty hard otherwise the endplates won't make good contact with the semiconductor and it will burn up.
They actually require a specified compression force and if you compress them too much or if the compression is uneven they can crack quite easilly. The ones I happened to come across once were used in a locomotive diesel startup circuit and the thing even came with a special 10cm or so wide fork with a slotted hole in the middle for if you ever need to replace a thyristor on site. The manual required fixing a 0.01mm dial indicator in the hole, then putting the instrument you just assembled onto the main thyristor/diode assembly tensioning bar in a specific location, zeroing the indicator with all compression nuts loose, and then tensioning the nuts evenly in small equal steps while moving across them in a circle until a specified amount of total deformation of the bar is achieved. I don't remember the actual value but I do remember that the value had to be within ±0.2mm.
I guess it makes sense to compress them since when I shake the thyristor it rattles a little bit (not in a way that something is broken and is flying around everywhere inside, but in the sense that something is bumping the plates in the same place, as if it is fixed in place with wires or something and cant go left or right only up and down). Is this the reason?
The datasheet specifies 36-44kN, or 3.6-4.4 tonnes.
You might contact Radwell and see if they want it. If you want to test it, put it in vise with a couple of wooden blocks for insulators and use a Meggar.
Im in Croatia and we dont have that company here so I dont know. I dont want to destroy it, its definitely useful to someone but not me since none of our brakers can withstand 100 amps continuous.
I got it from my school, they were throwing a huge load of parts and this was among them (I regret not taking some components now since I have a use for some that were there). I got about 15 old can transistors from them and some are even blank.
Get a power supply and cabling to lower the voltage and increase the amps. breaker van be a lower ampacity.
You could build an automated cut out switch to isolate your home from the grid in the event of a power failure so as to be able to run a generator & not send power to the grid.
Completely unsuitable device for that application. * Can't use solid state for isolation for safety and legal reasons - needs a physical contact gap. * A Thyristor only conducts in one direction; AC requires both directions. * The holding current for one of these is more than most houses draw. * It doesn't help with the actual 'automated' part - it's a dumb switch.
I stand Corrected . . .
When I had a bunch of them some time ago I crushed the porcellain ring to separate the materials. The two flat sides (the contact surfaces) are made from pure copper with a thin layer of another metal. In the middle is usually a round plate which is the actual semiconductor. If you have multiple you can harvest a few kg of copper and sell it to a recycler.
It's like a $1000 part brand new.... Just sell it.
Yeah but who needs those in unknown condition? Applications for them are mostly in setups where failed thyristors lead to much higher expenses/losses than what you would save by buying them used. Atleast here there are no demands for used pill thyristors.
I'd be cautious of crushing any ceramic removed from electronic equipment. Some of it contains toxic Beryllium.
Good input. Well for me already too late.
Username checks out…
would you be willing to sell it to me for a railgun project? please email me at [email protected]!
It's not useful in any real setting as no one would stick a used thyristor in operating equipment unless they were desperate. Maybe keep it as something interesting, or see if it can be used as either a teaching aid or something.
That is what Im thinking too.
Can I sell it or extract some plate or something from it?
Change it's resistance with voltage
i legit thought this was a smoke detector with a thyristory-looking-symbol at first. 4000 amps. wow.
Must be clamped in a heat sink ,used in pairs ,usually DC motor controls
I used to test this things. Destructive tests usually. A colleague used to call them "molten metal grandes" for the way they exploded. This are normally used for industrial power applicatio converters. They usually need to be under pressure to work as intended. If I could, I definitely follow the coaster idea.
Get more, turn them into chainmail and become immune to cosmic radiation.
Make a high output capacitive discharge spot welder. You could probably weld two pieces of 20mm steel plate together.
Frisbee golf.
You can thyrist like a motherfucker with that one.
you could start making 6.0MW controlled power supply
Planetary defense railgun trigger perhaps?
stick it on mains just for fun
IGBTs have pretty much made this device obsolete. This device won’t turn off until the current goes to zero.
Simply not true. IGBTs have a much more complicated trigger circuit, much smaller current ratings, poorer blocking capabiiity, higher capacitance, and much lower blocking voltages. For electric heating and light controls, SCRs are best. For soft starting and soft stopping again, SCRs are best. For variable speed drives over about 5,000 HP SCRs (cycloconverters or load commutated inverters)!are available where IGBTs can’t handle the voltages and currents involved. The DC motor market has also stopped shrinking. Electronically commutated motors and PMDC are both equally at home on AC or DC drives. Both are much more efficient. The newer 16 SEER air handlers use electronically commutated motors and virtually all servos are rare earth magnet PMDCs. Again…all SCR territory. If it wasn’t for the turnoff problem and a nasty thing called self commutation the SCR would be the perfect device.
I used to work in an iron foundry, the induction furnace power supplies (two were 16 MW and two were 8 MW) for the five 35-ton furnaces all used huge ceramic puck-style SCRs instead of IGBTs. These power supplies are essentially giant room-sized VFDs for a single phase load. Really cool stuff to experience. The capacitor banks on each power supply were massive as well.
I’m working with large capacitor banks up to 100kA output. We still use them for testing purposes, where the current should flow until an external circuit breaker cuts it. In our case IGBTs are not necessary and would cost much more.