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Beginners / Re: Capacitors(c,esr,losses,tables,meters,etc)
« Last post by ocw on Today at 08:07:46 AM »
I hope that the analog meter shown is reading an AC ESR value not a DC leakage figure--they are not the same thing.

It is important to use an AC frequency which is relevant to where the capacitor is installed.  If it is in a power supply I use 120 Hz.  If it is in an audio circuit 100, 1,000 or 10 kHz might be best to use.  For RF circuits, I use near the RF frequency used.

I have DC blocking capacitors used in 50 - 700 MHz power amplifiers fail due to lightning and other causes.  They are more susceptible to damage due to heat from poor cooling and excessive ESR and/or inadequate RF current rating causing added heat.  I measure the ESR of replacement capacitors up to 1300 MHz using a AIMUHF impedance analyzer.  The Rs measured using it amounts to the ESR at RF frequencies.

While not an example of a capacitor which I would used as a blocking capacitor in a RF amplifier, since I just measured it yesterday, attached is an analysis of a Taiyo Yuden TMK316SD104KL-T 0.1 uF 25V X5R capacitor in a metric 3216 SMD package.  The Rs/ESR is shown from 5 kHz to 800 MHz with a bit of a resonance around 700 MHz due to the attachment to the capacitor.  0.005 ohms is the minimum Rs/ESR value which can be measured, with 1 milliohm steps above that.  That high of capacitance can't be accurately measured using RF test frequencies, but the Rs/ESR values are still accurate.  I have verified the accuracy by observing the Rs/ESR change when adding a series resistor with the capacitor being tested.

I used a 20 GHz Vishay FC0603E50R0BTBST1 resistor to calibrate my testing method.

Similarly, I used a Vishay Y092610R0000T90  10.00 OHM 0.01% resistor to verify the accuracy of its low value resistance measurement.  Also attached is a recent 5 kHz - 50 MHz accuracy verification.  The Rs resistance stays very near that 10 ohm figure up to about 50 MHz and the inductance measured centers around 28 nH once the frequency is high enough for an accurate measurement of that low inductance.  That compares with the resistor's specification sheet saying that the resistor's typical inductance is typically 30 nH.  At high frequencies stray capacitance starts to lower the inductance measured.  Above 50 MHz the resistor starts to become resonant.
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Yes, Canadian wire colour codes the same as USA. 3-phase feeds usually red,black,blue. Neutral is white, ground is green.
I thought brown, yellow, orange are European colours. I can't buy that cable here.

Old 'somewhat  Euro standard' colors for 3-phase:
Black (P1), Brown (P2), Black-White/Pure White (P3), Blue (Neutral), Green-Yellow (Ground)

New european colors for 3 phase since 2001
Brown (P1),  Black (P2), Grey (P3), Blue (Neutral), Green-Yellow (Ground)


Also my friend is color blind (red-green if I remember right) and he constantly was discriminated when he mentioned it thus he was often sent to do "packing". What he was supposed to do before he mentioned his disability? He was supposed to write code...  :palm:

The problem is word "color blind" covers all cases for color disabilities, even the minor ones. From complete black&white sight to someone who sees regular blue as more darker blue or light blue.
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Beginners / Re: Can the wrong capacitor burn out a motor?
« Last post by Hero999 on Today at 08:05:28 AM »
Great -- we have three anwers, and they are
  • "The capacitor value is probably too high."
  • "The capacitor value has nothing to do with the problem."
  • "The capacitor value is probbly too low."
:-//

Glad you asked, Jacob, and I'm sure you can take it from there...
Sorry about the mess, and I don't pretend that I know the right answer.
All the sorts of answers you'll get when you don't provide enough information.

No make, model number, datasheet, photographs were given.
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Buy/Sell/Wanted / WTB TRW Cinch Edge Connector 5050A30 - 25 x 2 Pins
« Last post by Ookpik on Today at 08:04:43 AM »
Looking for a TRW Cinch edge connector.

Part number is 5050A30 / 251-25-30-160.

NSN is 5935-01-084-8897.

Should look like the one in the photo below.

Thanks!

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Whoever pays the bills and wages at Fluke needs to word up the engineers YESTERDAY   :=\ :=\  to look inside their CAD computers  :-/O and check out the 'user replaceable' BIOS backup battery arrangement on the main board,  :o :o
that's been in use across TWO CENTURIES of consumer electronics!!!!!!      :palm:  :palm:
It's not BIOS  :) RTC and probably temp offset, contrast and some user variables. http://media.fluke.com/documents/287-289_mveng0200.pdf
To be honestly, I do not see big problem with super capacitor except of shorting life of batteries. Even if you do not have warranty, you can easy to replace it oneself. I replaced super caps in my meter oneself just for save my time.
At any case they have new revision for PCB, let's see what will going on with

My point was to put a shake proof secured 'user replaceable battery' rather than a stupid leaky underated cRapacitor or dumbass soldered in battery that may leak too,
whose insides may be half fried by the soldering process to help along the inevitable.  -is not rocket science-  :palm:


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Take it apart!! :-+ 1st part of what many have waited for. The big transients are still to come..
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Well, the problem solved itself.
We found a pretty good color laser printer at a store sale, a Canon LBP7780Cx, which "unfortunately" isn't multifunction. It does a pretty good job with pictures (it want to for $700, even though it was supposed to be a $2500 printer but they were desperate to get rid of it)

To bad, well "have to" keep the monochrome one  :phew: .
Now I can make PCB's with color silk screen.

And I've got a new organ donor on the operation table.

I'll have a try with the new one, to see if it does any good for PCB transfer and let you know, in case someone else is interested to know.

I've got another quick question to avoid starting a new subject.
Are those photosensitive films you can buy online any good for homemade PCB's? Can you make finer traces than with laser transfer? (I can get reliable transfers down to 10 mils traces and 20 mils apart with toner transfer when I find the right paper)
I know you can buy pre-coated PCB's but they are quite expensive.
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Quote
I got a neat tip from a friend on hot melt glue - it softens in isopropyl alcohol, useful when cleaning it off a board.
This is one of the properties that makes it the most amazing thing in the universe. On smooth surface, a drop of alcohol makes it peel right off. In a blob of wires/fibers, alcohol softens the glue, making it tear and crumble more easily.

Hot glue is strong enough to use in finish carpentry in place of nails or conventional glue. It is strong enough to do a lot of things. But in most cases, is it possible to deconstruct hot glue joints relatively easily without any damage to the original parts. Hot glue is holding together a LOT of things in my workshop and in my electronics prototypes. Particularly when you are trying to figure out exactly where a tool holder, a button, a switch, etc needs to go and have to experiment with placement.

Conversely, where the parts that are joined are very rigid and there is no room for flex, even exposure to solvent won't separate the bond. Cell phone screens are on with what is basically a very thin layer of hotmelt glue.

don't forget hot glue is also very handy as a sort of "clamp" to hold things in place while the silicone or construction adhesive sets. ;)
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Repair / install new HD in lecroy waverunner 62xi
« Last post by al3x on Today at 07:58:56 AM »
i see adquiring new oscilloscope, one touch and great Sampling rate, in my locality sell this oscilloscope but i have dudes because the person not give me the hdd.

can i install new OS (for example win7) in new HDD and install x-stream?
Should I be freeze the HDD?
where find the software for new hdd??
i need any licence for install x-stream?
this for lecroy waverunner 62xi

thanks
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Beginners / Making a Hakko 470 work with an 807
« Last post by KnuckleheadFlow on Today at 07:53:16 AM »
(Actual problem in the last paragraph)

On a whim I bought a working Hakko 470 for a good price. Not having looked into it beforehand, I found it hard to find an 802 for a good price. On another whim, figuring "how different could they be?", I bought an 807. At first I was going to try to adapt the 470's board but realized pretty soon it'd be easier to just build a control board from scratch based on an Arduino Nano. I now know that I probably just should've bought a 47x control board compatible with the 807, but I've actually learned a bit so far and I've got the sunk cost fallacy going in full effect. Besides, I've got some nice Osram DLR2416 displays, it'd be nice to put one to use here. Having read the 470 and 473 manuals, and a bunch of Arduino based soldering iron (starting here) and dot matrix LED interface projects, I've got most of it planned out. Of course constructive criticism will be appreciated.


I figured out the display pretty quickly and I'll reuse the original pot to set the temperature. I figured out the sensor in the 807 is a PT50 RTD, found a resistance/temperature table for it and I've sorted out a voltage divider and op-amp circuit that should give me pretty accurate readings (±1°, way better than I need). I've also read up on getting accurate voltage reference for analog measurement with the Arduino.
(P1 and P2 here is to and from the sensor. A7 is on the Arduino Nano)


I was originally going to use PID and a MOSFET to control the heater, but I believe it'll be simpler to leave it AC and have it simply be turned on and off as needed (cycles on the order of seconds) with an optocoupler and TRIAC. There's a couple TRIACs on the 470's board I can reuse, the second would activate the pump.

What I really need help with is figuring out how the 807's button works. I had a look at the board in the 807 and when pressed, the trigger line has continuity with the heater's H2 line. I've found some useful photos of the 473's board on ebay and I've been using them to try to figure out how the IC reads a button press. To my DC-centric mind, the diodes seem to be going in the wrong direction! And if the heater is not on, how would the button press be detected?


Any help would be appreciated.

PCB front (distorted to line up with back)
PCB back (mirrored to line up with front)
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