What did you buy today? Post your latest purchase!

[BravoV]

Bunch of so called TI "Smart Diode" capable of 15 Amp with forward voltage at 26mV (0.026 V), of course there is always a catch with this low V_F. 

[DC1MC]

Not actually today:

- An army of AUGAT sockets, like 3 heavy divisions of 24 pins and some fast 16 pins along with (non-pictured) super heavy 40 and 28 pins, costed all together less then then 15EUR.
- A OCXO upgrade PCB for HP5385A from our forum member Miti and some 10MHz OCXOs from the famous Chinese seller Queenie . The OCXO are still burning happily and I'm waiting for their 1000 hours to start measuring them.
- Some 16,384MHz crystals, 5K ceramic trimpots along with some 280K reasonable stable resistors and some PTFE soldering points for my never ending poor-man calibrator project.
- An unexpected nice surprise, one forum member send me some famous voltage reference boards for the cost of shipping, thanks you know who you are  and if you reach Mannheim you WILL get drunk  , I even started one of the LM399 (the other one it's a bit strange, the heater works, but the diode has a very stable but just 1/10 of the normal output voltage  ?!?). The LTZ1000 are still on the "too poor to get the LTZ parts" lane.
- A (non-pictured) PREMA 6000 multimeter, advertised as with scanner and defective, got one perfectly working and with no scanner, no complaints here  .
- Ca. 3Kg of NOS resistors, 0,125-2W, not particularly high quality, but extremely cheap and not chinesified (terminal are thick and copper, usw).
- A Kelvin-Varley voltage divider DEKAPOT DP1211, see the Metrology thread for pictures and a tear-down, thanks again Ulf for helping with the shipping, the beers are waiting  .


Actually today, being pissed off that I've lost on of my monocular loupes:








Hopefully some of these Chinesium stuff will be useful.


 Cheers, DC1MC

[MrMobodies]

Thanks to Beanflying for helping me get some no longer sold, reliable sata to ide converters from an Australian seller who couldn't deliver internationally and I couldn't find them anywhere else.



I am grateful that there is great help on this board for all sorts of things.

[URI]

Some TEA again..

After acquiring a Fluke PM6881 universal 2 channel counter six weeks ago I spent my X-Mas money (and some more) today on a checked and fully working HP 53132A universal 2 channel counter (last cal'd up to 2016..).
Needless to say I don't really need it...      

[Specmaster]

OK then, not quite today but a couple of days ago I decided to buy a set of smart tweezers to make working with SMD stuff easier and decided that maybe it might be better to avoid both ends of the market and go for something a bit more, middle of the road sort of thing so I chose these chappies.

More info when I get them delivered.

[beanflying]

Had an arrival of a Heatshrink pack so I needed to make a better storage solution for it. Required the purchase of another bottle of Glenfiddich and consumption of a bit of the contents while the printer made the joiners. #winwin

The little baggy of leftovers will finish up in a drawer at this stage. This tree should stop multiple bits of the same colour or diameter getting started 'in theory'.

I might add another hole or two at intermediate heights so the bits sit closer to the tube.


edit - added a more complete shot including hotsnotted joiners and holes.

[aargee]

Why didn't you make the lid a cup to hold all the short bits?

Doubles as a strawberry planter as well.

Mine is a length of 90mm stormwater PVC pipe, cheaper o than printing the 3D bits but maybe not as stylish! I do like the size holes up the side. :-)

[beanflying]

Why didn't you make the lid a cup to hold all the short bits?

I did think about it. Currently the baggy is sitting under the lid as the tube is fairly full so it doesn't drop down. Maybe a MK II Lid is needed 

The holes are well worth it sorting through a mixed tube to get to the started lengths just doesn't work.

[beanflying]

An emergency button

Hopefully it's the last time I will deal unsafely with live 220Vac voltages... 

Just remember those contacts in there are not rated for continuous operation at 10A, and also they are not fail safe when disconnecting into a high current. They tend to weld together under heavy load, so best used in conjunction with a sensitive 16A AC1 rated contactor. Those at least will, when paired with the appropriate overload, provide good protection. Hope you also got some LED power on indicators to go with them.

The contactor should not be operated correctly, it is a safety button with locking, these buttons are used to control the circuit breaker trip coil - the most reliable disconnection -   - the coil acts on the circuit breaker locking mechanism

Correct, these emergency stop buttons are only rated for the coil current only and should never ever be used as a means of breaking the mains power supply directly, only via a suitably rated contactor

I know this is a week ago but a pair of very similar ones arrived in the mail today. Quick non destructive teardown for information. Allegedly 15A rated  Maybe 3A would be closer and even then ? This pair is going on my CNC via a properly rated relay to the power supply/vfd.

[Specmaster]

An emergency button

Hopefully it's the last time I will deal unsafely with live 220Vac voltages... 

Just remember those contacts in there are not rated for continuous operation at 10A, and also they are not fail safe when disconnecting into a high current. They tend to weld together under heavy load, so best used in conjunction with a sensitive 16A AC1 rated contactor. Those at least will, when paired with the appropriate overload, provide good protection. Hope you also got some LED power on indicators to go with them.

The contactor should not be operated correctly, it is a safety button with locking, these buttons are used to control the circuit breaker trip coil - the most reliable disconnection -   - the coil acts on the circuit breaker locking mechanism

Correct, these emergency stop buttons are only rated for the coil current only and should never ever be used as a means of breaking the mains power supply directly, only via a suitably rated contactor

I know this is a week ago but a pair of very similar ones arrived in the mail today. Quick non destructive teardown for information. Allegedly 15A rated  Maybe 3A would be closer and even then ? This pair is going on my CNC via a properly rated relay to the power supply/vfd.

Hopefully a contactor, not a relay as relays tends to have silver contacts and can evaporate with arcing caused by motor currents. Contractors on the hand gave silver oxide cadium contacts to withstand the arcing.

[beanflying]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

[Cubdriver]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

The thing that comes to mind with that is, isn't a coffee maker typically pretty much a purely resistive load?  It's likely not an issue, but might be something to consider.  What sort of load will the CNC machine present - something more inductive and potentially arcy-sparky?

-Pat

[beanflying]

Power Supply and a VFD on the Head so no harsh on/off and under 3kW total (<15A).

Espresso machines are hard on or off and the contacts are 20A rated each x 3 so cruising in this case. I have never seen one of these fail in a modern machine and some are 7.5kW+ running the same contactor in a lot of cases.

[Specmaster]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

The thing that comes to mind with that is, isn't a coffee maker typically pretty much a purely resistive load?  It's likely not an issue, but might be something to consider.  What sort of load will the CNC machine present - something more inductive and potentially arcy-sparky?

-Pat

I would tend to agree with you Pat. I used to look after many vending machines including coffee makers and they are mainly resistive loads. I have been called out to so many alleged faulty gear call calls over the years where people who really should know better have built huge great motor control panels for production process that have cost thousands of pounds in damages because the so called professionals used hundreds of relays to control motors on automation of production plants that have failed and ground the entire factory to a halt as a result. Replacing the relays with proper contactors cured the problem permanently and the same panels were still in daily use when they closed the factory many years later and demolished it to make way for housing and a retail park and the only difference is the contact material, a small but vital detail to get right.

[Specmaster]

Power Supply and a VFD on the Head so no harsh on/off and under 3kW total (<15A).

Espresso machines are hard on or off and the contacts are 20A rated each x 3 so cruising in this case. I have never seen one of these fail in a modern machine and some are 7.5kW+ running the same contactor in a lot of cases.

That may be so, but I would do my homework on the contactor / relay part number that you're using to make sure what the contact material is because contactor contacts tend to be rated as AC4 (inching and plugging as you would do on a crane) which is the most difficult load to switch on because of the massive inrush currents, switching off is not so hard to do.

Check the following link and look at the table there which details the massive inrush currents that contractors have to handle (AC2, AC3 and AC4 ratings, AC1 rating can be handled in most cases by a relay if there is very little inductive loading on the circuit.

https://electrical-engineering-portal.com/contactors-direct-on-line-starters

[beanflying]

Worst case here is likely to be a tool crashing into the bed which already has proximity sensors on it and disables the VFD. VFD failure and magic smoke release to short will likely trigger the ELCB or fuse board breaker before I can get to the stop switch.

So the emergency stops and contactor are more belts and braces to keep me happy I can manually kill it rather then yank the plug out of the wall (like its former owner used to have available) or if I lift the lid to do something with fleshy bits near the pointy bits keep the spindle from firing up. 


edit found a spec sheet AC3 12A / contact

[Edison]

Safety buttons on the industrial trigger are mechanically solved - by pressing, the contacts disconnect mechanically, not electrically (with the exception of security coils circuit breakers and switches). With electrical disconnection, this is considered to be a normal "Stop" button whatever its shape.

[Edison]

  Back to shopping     

[Gary350z]

This is a magnetic ferrite core memory plane.
("Plane" seems to be the correct term for this.)
I purchased this on ebay from the Russian Federation for $35 including shipping. The shipping time from Russia to the USA was about one week. I didn't have 100% confidance that it would arrive, but it did.
 
This magnetic core memory plane was made in the USSR in 1970s.
It is a 32x32 core memory plane that stores 1024 bits (128 bytes) of data.
The plane outside dimensions are 4.4" x 4.4".
This plane is one of 20 planes forming a magnetic core memory block. The capacity of the whole block is 2560 bytes.

[beanflying]

Very Shame I am trying to slim down the collection of 'stuff' but it is fairly slim and maybe in a frame ..... 

[McBryce]

Yup, they make a nice decoration when framed. Here's mine, probably from the same seller, that I bought a few years ago.

McBryce.

[KaneTW]

A HP 4140B and a Merck Spectroquant NOVA 30.

[cdev]

They are really amazing looking.

Tri-state memory!

This is a magnetic ferrite core memory plane.
("Plane" seems to be the correct term for this.)
I purchased this on ebay from the Russian Federation for $35 including shipping. The shipping time from Russia to the USA was about one week. I didn't have 100% confidance that it would arrive, but it did.
 
This magnetic core memory plane was made in the USSR in 1970s.
It is a 32x32 core memory plane that stores 1024 bits (128 bytes) of data.
The plane outside dimensions are 4.4" x 4.4".
This plane is one of 20 planes forming a magnetic core memory block. The capacity of the whole block is 2560 bytes.

[beanflying]

Yup, they make a nice decoration when framed. Here's mine, probably from the same seller, that I bought a few years ago.

McBryce.

That's just evil No No I won't succumb to the pretty pictures.   

[bitseeker]

You guys! Why do you do this to me? Very cool historically nerdy decor. For how long can I resist not buying one?