Mini-PV is the standard (in that DuPont used to make them), but the M20 clones are more common. It was created by Berg, who got bought out by DuPont, who spun those off to FCI and then that went to Amphenol decades ago. Then Harwin made their M20 connectors as a near clone of Mini-PV, but they aren’t a perfect fit with Mini-PV housings (and vice versa). M20 won’t fit in a Mini-PV housing, and Mini-PV will be loose in an M20 housing. Then tons of other manufacturers started cloning M20. Most cheap leads you get will be M20.
I tend to just make my own M20 jumpers since that lets me set the length. Mini-PV is necessary if you want more options for wire gauge or spring tension though.
Looks like you are well on your way for a safe battery. Been playing with these types of cells for years now and I use really thin tinned copper wire to act as a fuse. The real issue you will see if you use “heaters”. These are known cell types typically red Sanyo’s that over time when fully charged start to self discharge which generates heat. Mitigate that issue and they are really stable. I have even direct shorted a 80p pack by accident and all it did was blow the fuses. Anytime you are building this stuff yourself you need to keep an eye on it either with some software that tracks each cell (generally a cell means one parallel set of cells) for voltage and current usage. Also if your bms can record how much any cell balances can show issues before they become a hazard.
My biggest recommendation is to put it outside away from your house. This is the easiest and safest way of protecting your house. Barring the ability to do that a good metal enclosure with exhaust to the outside is a must
I'd assume that since it's from a thermostat, it's likely a custom made part - most of the common traditional thermostat companies like have been around for a while tend to mostly reuse their existing custom designs instead of using standardised components
Since it's peeling this could be difficult to salvage too... usually I use foil to solve connection issues caused by corrosion, or have a poke around on Ebay for a secondhand one if it's really bad
You could also consider re-shaping a (conductive) paperclip to contact the aa battery in a similar way.
I've had middling-to-good results making battery contacts out of springy bronze metal stock. It solders well, it's easy to shape, and if you get the right kind of metal it retains its springiness well. (510 or 544 alloy, maybe? It's been a while.)
If you are completely new I suggest watching a tutorial. Otherwise some basic tips could be
if oscilloscope has multiple channels, make sure the channel you connected is the channel nel you see on the screen
make sure you did the ground connection. You need to connect both signal and ground tips if the probe
make sure voltage range is fine. If you use a large range in the screen, little amplitude you got may seem like a flat line.
calibrate your probe, if oscilloscope has that option. But an uncalibrated probe doesn’t explain flat line, it would explain distorted square wave, for example.
Use another probe. They can get broken. If it is broken all you will see will be the noise the cable pics up like an antenna.
separate the issue. Connect probe ends to a battery with k own voltage and see what you receive. If it doesn’t work, you know either probe or oscilloscope is wrong.
List can get longer really, but I think a tutorial and these can go a long way for the beginning.
As the other commentor said, ebay is a good place to look for such things but don’t search the part numbers. Search the model number of your device. Get the model number as specific as possible. Sometimes there’ll be a model number printed on the outside or on the box it came in, and that number is like a customer facing model number with a different model number that the manufacturer goes by. Like you’ll have a Samsung Note 8 and that sounds like the model, right? But in reality, it’s a SM-428Z-J12 or something. That’s the model number you want to search. Do some research on your device to get the right one.
DuPont connectors equates to logic level signals. There may even be a 3.3 v <>5v link selector on the adapter.
Whereas DB9 equates to "RS232" level signals. Generally, at least the capability to accept those voltage levels, even if not necessarily producing them.
My first step tends to be to connect tx to rx and see if characters typed in a terminal/emulator get echoed.
An RS232 breakout box is pretty much a given necessity, when it comes to sorting out what's happening on all those pins and sorting out what to connect to what.
In my experience, if they don't include the conductor in the connector, there will generally not be a wire for it in the cable. So replacing the USB-C connector is probably not going to add any functionality.
I have a stack of USB-A to USB mini/micro cables that are a bit like this. Two conductors, only do charging. So if I replace the connector, there's no wire to connect the D+ / D- lines to. It's quite possible the manufacturer of your cable had some similar or otherwise reduced feature set in mind, and wanted to save 5 cents of copper.
I also have some cursed cables that have normal ports, but only two wires inside the cable (power/ground), or are otherwise out-of-spec in ways that make the data lines mostly fail. These have wasted quite a bit of my time over the years.
I only need a USB 2.0 cable mostly for charging, I have better cables, I chose this one for the liquid silicone outer layer. Of course if the wires inside are less than four or too thin I won't waste USB connectors (that I already have, I would not order them for this) and I will recycle it.
Wear trainers not sling backs. Molten solder and your tootsie don't go well together.
I turn the printed circuit board component side down and wave a hot air gun over the flip side, whilst tapping the board against the edge of work bench. The result is usually a cascade of components (and blobs of molten solder).
Very therapeutic. When I'm stuck trying to work out how to do something, when everything I have tried has failed miserably, I deconstruct something electronic. No, I keep well away from psychiatrists.
You (I anticipate) won't be doing this 9 hours a day, 7 days a week - most of the nasties are long term exposure ones, so a one-off should be fine. If anything ever irritates your eyes or throat, get out of there and ventilate the place.
Using MOSFETs as TID sensors is common enough. A term that you can use for more research is RADFET. The best way to measure threshold voltage is to sweep the gate voltage. In my experience however, if you intend to measure this in a non-lab environment (say, in a satellite), I would recommend that you instead connect the gate to the drain, force a small constant current (maybe 10uA) from the drain to source, and measure Vds (which is equal to Vgs in this configuration). This won't give you the threshold voltage per se, but this will produce a voltage that changes as dose accumulates, is a far easier metric to measure, and is as equally valid as measuring the threshold voltage to determine TID. You can't really predict the shift in threshold voltage according to TID unless your MOSFETs are all from the same batch (manufacturing defects and tolerances), and you need to calibrate them in order to obtain a calibration curve (this is done by simply going to irradiate several (the more the better, I suggest at least 10 for statistical significance). Alternatively, you can buy pre-calibrated ones from companies who make MOSFETs for this intended purpose like Varadis. If you really want to measure the threshold voltage, you could read MIL-STD-750, which outlines how to measure the threshold voltage.
Hey I messaged them a bit, this is an undergraduate project with no budget (so a MOSFET tester is out of budget). I also suggested a sort of sweep method using an MCU and some op-amp glue, but I don't think they have sufficient background to get this kind of thing working yet (in fact I barely do, so probably it won't 'just work' with whatever I came up with off the top of my head).
What I was thinking is perhaps they can set Vds and Vgs to fixed values such that a particular MOSFET conducts a fixed current, e.g. 100mA, somewhere near-ish the start of the linear region. Then record the Vgs required to achieve this current for each of a set of MOSFETs, say a few dozen (because of part variation).
Then after exposing them to varying amounts of radiation (a few for each exposure level), put them back in the same test conditions and measure how the output current has changed, what Vgs will restore the same current, draw some graphs, discuss the advantages and disadvantages relative to the Vth method with regards to radiation dosimetry, conclude, and call it a day.
Think it would work? No need for an MCU or signals processing this way, so the science can get done with the tools they have.
Also I never had free access to strong radiations sources in undergrad, so am a little jealous. I barely got to use tritium, and that sparingly.
Hello, do i still need to apply a supply voltage of Vgs, or will only the current at the drain be the main source. Also, is this MOSFET sensitive enough for a cs-137 (661 keV).
Ultimately, yes you will need to bias the gate. If you put the MOSFET in the diode connection mode, the gate will automatically be biased when you force a constant Ids current. While I have never worked with this MOSFET nor with Cs137, I don’t see why it wouldn’t be sensitive. A few notes:
This MOSFET is in a TO-247 package, so make sure that you have the front of the MOSFET pointed towards the Cs137 source during irradiation, otherwise the leadframe will likely act as an attenuator, reducing the sensitivity.
This MOSFET is a HEXFET, which normally aren’t designed for continuous high DC power dissipation (they are meant for switching). So keeping the dissipated power in the FET would be best.
I’m not sure if there is a difference in general sensitivity between HEXFETs and other MOSFET types like VDMOS or traditional monolithic planar MOSFETs.
I’m not sure if you already planned this, put generally it is recommended for the MOSFET to have all pins grounded during irradiation. Biasing of the MOSFET can affect its sensitivity (depends on every MOSFET), so having all pins grounded keeps them in a constant state during irradiation (and lets all accumulated charge get shunted to ground, preventing ESD damage).
I’m not entirely sure, but I suspect that the die is mounted to the leadframe on the flat side of the package. In this case you should point the flat side towards the source.
I’m using lm334z as a current source, i’m still thinking and deciding on where to connect it to the MOSFET. Can you propose the wiring for the current source input once the MOSFET is in diode connection. Like for example, in a breadboard i used a wire to connect the drain and gate. then, i’ve applied a constant current at drain terminal with source connected to the negative. So to check the change in voltage, should i measure the voltage in Gate to source?
Hello, I have already tried to apply a microampere current (around 40 μA) using only Ohm’s law. I used a 2V input and a resistor in series. However, the LM334z is not working, and I am unsure of the reason for its failure. Will using an input voltage and a resistor in series work just fine?
I have also measured the Vgs, which reads at around 0.117 mV. What do you think about the measured Vgs? Technically, it should be around these values, right? Considering that there is a very small current.
You will probably need to increase your voltage. I haven’t ever used the LM334, but it will need a minimum voltage across it. I don’t know if you are still using the IRFP250N, but if so it has a threshold somewhere between 2V and 4V for 250uA, so the threshold won’t be as high but it should be close. I would try using 5V if it’s fine with your setup.
For the suitability of the resistor method, you should do the math on how a change in Vds will affect the current, and then calculate how much this variability in current will affect your readings. If this error/innacuracy is acceptable, then why not.
Do you mean that to properly operate the LM334, we need to apply or reached the threshold voltage of the MOSFET which is around (2 and 4V)? But, i’ve tried to used it (LM334z) as a standalone and still it doesn’t work. maybe the LM334z is the problem hahaha *Regarding the resistor method, What do you think about the measured Vds, Vds=117mV (With an input current of 40uA)? i’m confused with the “how a change in Vds will affect the current” *Isn’t it Vds the parameter required for determining the dose? So if there is a constant current and resistance, how does the radiation affects the MOSFET? Will resistance or current increase upon irradiation leading to an increase in the measured Vds?
You will need to provide a voltage of at least the threshold voltage PLUS the minimum voltage of the LM334Z. If the LM334Z circuit by itself doesn’t work, that will be the first problem to figure out. Make sure you completely read through the datasheet www.ti.com/lit/ds/symlink/lm334.pdf?ts=1689139734…, there are example circuits in it for reference. For the resistor method, keep in mind that the current isn’t constant; the voltage is. Your current is dictated by your resistor and the voltage across it, which is the supply voltage minus the threshold voltage. If your threshold voltage changes as the dose increases (which is the typical behaviour), the voltage across the resistor will change, therefore your current will change, which will generate error in your reading. The only way to minimize this error is to apply a very high voltage (100’s to 1000’s of volts) to the resistor, such that a change in the threshold would become a rounding error.
Connect the gate to a function generator via a series resistor. (Gnd on the source pin) Drive it with a square wave 0v low 5+v high and observe the gate voltage on the oscilloscope. You will see a little plateau spot in the waveform, this is at the gate threshold voltage.
Does your CPU has integrated graphics? You can remove your GPU and then you test if the error still occurs to find out if your GPU has damage. You can also test a live system, to exclude issues in your OS or driver configuration
Not an expert, but it wouldn’t hurt checking if it’s a bad RAM. If you have multiple sticks, you could try using your PC with just one at a time, to check if it’s one of them dying.
You can run Memtest, just boot it and check the ram. Some Linux distros have memtest included in their bootable image (e.g. Ubuntu). Otherwise you can create a bootable stick with memtest by yourself.
This one should have you covered. They’re quite nifty. Can do a lot more than what you ask.
USB C Tester,KJ-KayJI 2 in 1 Tester Color Screen IPS Digital Multimeter(2022),Voltage,Cur,Pwr,Resistance,Elec,Temp,Capacity,Tme,Fast Charging,with USB Clip Cable Support PD2.0/PD3.0,QC2.0/QC3.0,BC1.2 a.co/d/6RlmtOo
askelectronics
Top
This magazine is from a federated server and may be incomplete. Browse more on the original instance.