Was very lucky today, my latest arrival from Fleabay was very lucky in that it was not amongst the lot stolen this morning when the PO was burgled again. 2 times in 2 weeks, and same MO in both cases.
Got my cheap "As seen on BigClive" RFID copier, and a dozen assorted tags to go with it. 2 AAA cells and it does work as well, just copied some tags I have around and they do work.
How much did you spent on that copier? I'm planning to build one with an arduino for about 3 years
Yihua 908B soldering pencil with fume extractor line to replace the original one that came with the station (also pictured). I got this new from an Australian company (of all places) for roughly $22 USD. I had planned to rig up some kind of home-made vac and filter system, then I saw this at my favorite local electronics recycler....
a Weller WFE-2P "Zero Smog" Fume Extractor. They had it listed at $50 and, as always, I negotiated and got it to CAD $20 (~$15 USD). Works perfectly. The filters look fine, and given the small amount I will use it, I don't even know if I will ever need to replace them. This unit retails at about $1000 USD and a new set of filters will run me about $60. Combined with the 908B iron, I can now solder with nearly zero fumes. I still do plan to make a DIY large area fume extractor.
One of my favorite activities is shopping at local industrial surplus store and hunting for cheap surplus high quality caps as they become rare day by day since most of them are now invaded by those crappy Chinese brands.
This time is quite unique at least to me, as I spotted quite rare Nippon Chemi Con GXE series caps which is rated at 125C, and others ordinary low impedance like KY and KZH series.
An old classic this one. Poorly titled win for £18 including postage on ebay.
Needs a bit of refurb and the caps changing due to the age but will be handy for a couple of discrete logic and transistor based projects I have lined up.
PCB mount fuse holders and panel mount fuse holders.
I bought a Bachmann CONNECTUS for 8 euro.Unfortunately i tested when i got home,even when the switch is closed it is a contact between phase and neutral
I finally unboxed the LED shop lights I bought from Home Depot that arrived last week. I'm pretty happy with them. They're only 3 feet long, not very heavy, and rated 3200 lumens at 42 watts. In reality the one fixture seemed considerably brighter than the two F40-T12 tubes in my kitchen ceiling light. The picture is pretty bad I know, but it was kind of hard to hold the light against the ceiling in one hand and the camera in the other while standing on a milk crate.
http://www.homedepot.com/p/Commercial-Electric-3-ft-LED-Black-Shop-Light-54254141/206028863I bought 2 for $30 each, so shipping was included, but sales tax added a bit more than $4
I bought a Bachmann CONNECTUS for 8 euro.Unfortunately i tested when i got home,even when the switch is closed it is a contact between phase and neutral
Contact closed = turn on
Contact open = turn off
I uploaded another photo.I don't think it is normal to be some connection bewteen phase and neutral
I uploaded another photo.I don't think it is normal to be some connection bewteen phase and neutral
We can't see what your meter is measuring? Ohms? K Ohms? uSiemens? There is a convenient glare right where the display shows the units.
It seems likely that you are measuring residual leakage from whatever kind of silly "noise filter" or "surge protector" components that may be inside.
I uploaded another photo.I don't think it is normal to be some connection bewteen phase and neutral
We can't see what your meter is measuring? Ohms? K Ohms? uSiemens? There is a convenient glare right where the display shows the units.
It seems likely that you are measuring residual leakage from whatever kind of silly "noise filter" or "surge protector" components that may be inside.
It is 135 K Ohms.
I open the socket strip to see what is inside.Because it has one way screws, had to drill holes in screw.
Then i saw the circuit and i understand how it works.I have soket strip from APC and Belkin and all show OL when i try to measure resistance between phase and null
It is 135 K Ohms.
Do you understand now? There's a circuit there, to run LEDs, and it operates off the phase and neutral lines. Of course that's going to be measurable with your meter.
[/quote]I have soket strip from APC and Belkin and all show OL when i try to measure resistance between phase and null
[/quote]
Because they are just wires, no electronics.
I don't know why you didn't just plug it into the wall socket initially. It either works or goes bang. In the 2nd case you get a warranty replacement. Now you've drilled out screws etc, even if it fails you have no chance of a replacement.
It is 135 K Ohms.
Do you understand now? There's a circuit there, to run LEDs, and it operates off the phase and neutral lines. Of course that's going to be measurable with your meter.
I have soket strip from APC and Belkin and all show OL when i try to measure resistance between phase and null
[/quote]
Because they are just wires, no electronics.
I don't know why you didn't just plug it into the wall socket initially. It either works or goes bang. In the 2nd case you get a warranty replacement. Now you've drilled out screws etc, even if it fails you have no chance of a replacement.
[/quote]
Yes i understand the circuit.About warranty,i paid 8 euro because store went bankrupt (the warranty does not exist )
Realize also, super simplifying, that at 240V, have 135K across it is about 1.8 milliamps. At 120V, it would be less than 1 ma. That's nothing.
One of the common ways to drive detection on model railroads so that you can determine if a track is occupied or not is to detect current flow through the rails. With more modern control systems where the voltage across the rails is constant, instead of the old variable sort of thing where the voltage controlled the speed, this is pretty easy. A powered unit (with a motor) or anything with lights, that's obvious, there is a load in place. But for freight cars - what do you do? The common option is to put a resistor across the wheels. Most circuits for detection can 'see' with a single 15K resistor, but for reliability (wheels and track get dirty, etc), a more common value is 4.7K per car. I put a 10K resistor on 2 axles of each of mine (most US railcars have at least 4 axles) so it's about 5K per car. Now multiply by several hundred such cars (on our club layout, I will never be able to have that many on my personal layout). Yes, it finally starts to become a somewhat significant value, but when each power supply can supply 5 amps, and you have 4 or 5 of these driving different sections, so only a fraction of the total number of cars is drawing from any given power supply, it's no big deal. With a nominal 4.7k resistance, and a typical voltage of 15V, worst case is about 3.2ma per car. However, less than ideal electrical connections between the wheels and the rails increases the effective resistance. Say somewhere closer to 10K, unless you scrub the wheels and track and press the car down hard. So now we're talking about 1.5ma per car. Even with more than 10x the voltage, this circuit in the power bar is drawing less current than a model train car fitted for detection. You could stick an equivalent resistor in an outlet (don't do this.....) and it won't even get warm. On 240V, it's less than half a watt.
Cool, I have one of those too. I got mine about 10 years ago. It came in what might have been the original box along with the manual and some other parts. Judging by the sticker on the outside, it was apparently property of AT&T at one time.
Those 545A's are pretty cool. I found a manual for them online. I am actually working on an 8 channel logic probe with the fast signal detection that the 545A has. It will detect a pulse as quick as 35ns (and faster but not guaranteed) and report it as 10 Hz blinking like the 545A.
There's an older thread here discussing the family, but mostly about the 547A current tracer. I also came across this publication from HP the discusses the design and use of each of the 3 tools - pretty neat. It even has bios of the lead engineer for each tool - including the ME who designed the cases for them.
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1976-12.pdfFancy stuff. Back in the day, I had a cheapy Radio Shack logic probe.
I've got the HP 547A current tracer version here. I've only used it a few times but it can be useful when looking for shorts or tracing other current paths in a PCB.
How often do the lamps fail and need to be replaced? Mine hasn't failed yet but I do wonder what the lifetime is for the little internal lamp.
Just bought an old Leader precision fully analogue LCR bridge off ebay so I can do Q, inductance and ESR measurements as well as test incoming and extracted components.
Teardown will appear when it turns up if parcel force don't destroy it.
Hoping that I can get my 7T11 working completely now that I have this:
Tr <= 25 ps, baby
Hmm. My 7T11 definitely has problems. I'm going to have to dig into the manual for it. I was able to get some plausible X-Y action with a pair of both of my 7S11 plugins (one with a lesser sampling head), unfortunately that's not so interesting to me.
The 7T11 has a lot of exciting stuff, including a buttload of reed relays.
This, I am sure is boring, but I can't find these longer headers with a centered stop on eBay. So I got it from Pololu. I am impressed with the really great little package they put it in. So professional, all the way.
I've got the HP 547A current tracer version here. I've only used it a few times but it can be useful when looking for shorts or tracing other current paths in a PCB.
How often do the lamps fail and need to be replaced? Mine hasn't failed yet but I do wonder what the lifetime is for the little internal lamp.
I doubt you need to worry too much about it, if it's survived since the 80s it's probably got a lot of life left still left in it. If you haven't seen it there is a thread I started a while back when I got my set.
https://www.eevblog.com/forum/reviews/hp-547a-current-tracer/
KUSB-3108 low-cost, multifunction data acquisition modules
and
2 x 250ml 100% isopropyl alcohol
from ebay
Siglent SDG2024X function generator.
Primary use is going to be educational, as in, tinker tinker, plug signal in, measure output, wonder why it's not working
First test is attached, sweeping sine wave (green trace) through an RC highpass filter (yellow.) I've been trying to understand the frequency response of RC circuits through textbooks and wikis for a while now and it never quite clicked. Seeing this in action makes it so much easier to understand, very rewarding
#Edit Whoops the scope image seems to be upside down -- Ah well