IC hook test leads - Page 1
Forum section: electronics / testgear

author: smbaker
author_rank: Regular Contributor
timestamp: September 24, 2017, 01:54:59 am
content: I have a couple sets of these:https://www.sparkfun.com/products/501. I've heard them referred to as "mini grabbers" before, though sometimes I see both large and small clips listed as "mini grabbers". These are the small ones. They've finally become crusty enough that they need to be thrown out and replaced. I'd buy the same things but for the following problems:1) There's no strain relief and the wire crumbles away within a half-dozen uses (can be easily solved with a blob of hot-melt blue, but still...)2) The metal clip seems to bend easily, and I'm constantly having to bend them back into a hook shape.3) The plastic melts very easily, if you have it attached to a component that gets hot. This is what seems to have slowly rendered all of mine useless over the last few years.I've also purchased a few of this style:https://www.sparkfun.com/products/9741, but they're even worse with the metal clips easily getting bent and needing to be constantly bent back into shape.Are there anything better? That doesn't cost a fortune?Thanks,Scott

author: DaJMasta
author_rank: Super Contributor
timestamp: September 24, 2017, 02:53:40 am
content: Sometimes they're mini hooks or similar, and there are other makers, I've got some Pomona mini grabbers that do a great job and probably come with a bit higher gauge wire, but they are typically expensive. You can sometimes catch a lot of used ones on ebay for relatively cheap, you can also buy just the hook individually for very little, then build your own cable/strain relief onto it.I wouldn't use those on ICs, though, I use them on headers/cables. I'd look at test clips for logic analyzers, as they'll be a smaller size and better suited for work with ICs. There have been some discussions on ones for really precision work, but you can get very inexpensive ones with 0.1" header connections coming out of them, or you can get nicer quality ones like the HP 5090-4833 - I picked up a handful of them for about $1 each a while back on ebay sold secondhand.

author: hermit
author_rank: Frequent Contributor
timestamp: September 24, 2017, 03:14:54 am
content: Should be around the 35 minute mark.

author: cstratton
author_rank: Regular Contributor
timestamp: September 24, 2017, 05:02:13 am
content: If you want to connect to IC's, don't waste your money on the cheap stuff, get the real ones, for example 461-1011-ND.These seems to work well with 2mm crimp contacts on silicone wire, individually heat shrinked. 100 mil contact will work to a degree, but not in those silly square plastic housings.If you don't feel like springing for the color assortment just get enough of the gray ones for JTAG/SPI and decorate them when the office supply store puts the color pack of sharpie markers on back-to-school markdown.

author: smbaker
author_rank: Regular Contributor
timestamp: September 24, 2017, 05:41:49 am
content: Quote from: DaJMasta on September 24, 2017, 02:53:40 amHmm, this does seem to make more sense than what I've been doing. How large will these style hooks work? They seem to be generally described as "SMD clips"... Will they fit through-hole ICs, resistor leads, 0.100 header pins, etc?I see E-Z-Hook does have the XR25 series if I need something larger, but it would be nice if one hook could serve most of my purposes.Scott

author: DaJMasta
author_rank: Super Contributor
timestamp: September 24, 2017, 06:27:25 am
content: Using just the smaller, logic analyzer style clips is just fine for many uses, but they are a bit too small for handling much current, so they're not a good choice for powering boards and such. The Hook style clips get a little firmer grip on a header or board hole, so they're less likely to come off. I'm a fan of banana jacks to test hooks from the power supply, some test hooks to test hooks for jumping power or big signals around (or just to larger clip points), then the logic analyzer size for actually grabbing onto chips for signal level stuff.I'm not sure there's a great one-size-fits all option, but it doesn't take more than a couple pairs of leads and a handful of clips with some single pin jumper cables (and maybe a couple alligators for good measure) before you can have a good jumper for most types of signals and tie points you'd find on your bench.

author: tautech
author_rank: Super Contributor
timestamp: September 24, 2017, 07:55:43 am
content: Scott, keep your eye open for small lots of these:http://www.ebay.com/itm/Tektronix-Adapter-Mini-Test-Grabber-40V-/272670551628?epid=1300248025&hash=item3f7c6e6e4c:g:YsEAAOSw42dZF6bpYou'll need 0.25 female crimp connectors to join onto them too.

author: alm
author_rank: Super Contributor
timestamp: September 24, 2017, 10:21:46 am
content: Quote from: smbaker on September 24, 2017, 01:54:59 amDon't buy cheap crap. You really get what you pay for with cheap grabbers in my experience. I've been happy with Pomona leads. Heavier silicone wire will survive longer, and the hooks are much sturdier.Quote from: smbaker on September 24, 2017, 01:54:59 amThe grabber hooks are generally not suited for high current or hot places. TheParrot Clipsmight work better for those applications.Quote from: smbaker on September 24, 2017, 01:54:59 amLook for Tektronix SMG50 (see the link tautech posted), the hooks shipped with HP/Agilent logic analyzer pods or EZ-Hook XKM clips. The former two can regularly be found on eBay in lots for 1-2$/ea. All of these terminate into a pin that fits 0.025" square pin or 0.030" round pin headers. These are designed for DIP and SOIC. They are not great for 0.025" square pins or power transistors.

author: BFX
author_rank: Frequent Contributor
timestamp: September 24, 2017, 01:07:37 pm
content: The best what I found is hirschmann. They are really well made and I haven't any problem so far.http://uk.farnell.com/hirschmann-testmeasurement/973972101/hook-test-miniature-mlb/dp/523409Sometimes they are also much cheaper on eBay in sets. I bought a set of 10 for about 14 EUR.But beware because I've seen some Chinese fakes already. (see original package)

author: smbaker
author_rank: Regular Contributor
timestamp: September 26, 2017, 12:56:29 am
content: Thanks everyone for the suggestions, I think I'm going to pick up some E-Z-Hook XKM on my next digikey order.I saw Dave's review of the parrot clips a while back, though I promptly forgot about them. My biggest concern with those would be shorting -- when clipping onto something like an 0.100 header, it seems like the parrot clip could easily short an adjacent pin.Scott

author: alm
author_rank: Super Contributor
timestamp: September 26, 2017, 07:33:10 pm
content: Agreed, I would not use parrot clips on 0.1" or finer pitch. However, how many DIP/SOIC ICs do you have that get hot enough to melt the clips or draw enough current to exceed the 1 A or so the small clips are rated at? I'm sure there are some FETs in a tiny package that can switch dozens of amps that are the exception. Use something heavier duty like parrot clips when probing power devices or powering boards, and smaller clips like EZ-Hook XKM for low-current signals on fine pitch devices. Parrot clips are still infinitely better than alligator clips for PCB work in my experience.

author: tggzzz
author_rank: Super Contributor
timestamp: September 29, 2017, 09:15:31 am
content: The related question is what wires do you use with any of these clips?Naturally the wire should be infinitely flexible, have zero weight, and not fracture when repeatedly bent. How close can we get to that ideal?

author: tooki
author_rank: Super Contributor
timestamp: September 29, 2017, 04:39:07 pm
content: 24ga stranded silicone?

author: tggzzz
author_rank: Super Contributor
timestamp: September 29, 2017, 05:28:09 pm
content: Quote from: tooki on September 29, 2017, 04:39:07 pmWhat's "24ga"? If you mean "24 awg", then is there any reason to believe it is substantially better than 28awg or 22 awg? (Experience doing X would be an excellent reason!)If someone has experience of using a specific part, pointers would be welcomed.Is there any known source of twisted pair (as inHPAgilentKeysight's cables), one for the signal and optionally one for the ground?

author: macboy
author_rank: Super Contributor
timestamp: September 29, 2017, 06:17:19 pm
content: Quote from: tggzzz on September 29, 2017, 09:15:31 amI have purchased silicone wire from this aliexpress store in the past, and it was good quality with actual heat proof silicone insulation and high strand count (many hundreds of very fine strands in the 14 awg I bought). It also had the correct weight and resistance per length for actual copper. I have never tried their 30 awg size, but at just 0.8 mm outside diameter, silicone, and fine strands, it should be about as light, flexible, and durable as you can expect.I have no relationship with this seller and this is not an affiliate link. I just like to share when a seller has the "good stuff".https://www.aliexpress.com/store/product/30AWG-Flexible-Silicone-Wire-Cable-Soft-High-Temperature-Tinned-copper-UL-VW-1-Black-5M/1851538_32429516910.htmlp.s. it comes in 8 colors which can be very handy for this application.

author: tggzzz
author_rank: Super Contributor
timestamp: September 29, 2017, 06:41:16 pm
content: Quote from: macboy on September 29, 2017, 06:17:19 pmThanks for that.I wonder if there is a way of assessing whether 30AWG is too easily breakable, either by stretching or stress fracturing.

author: nanofrog
author_rank: Super Contributor
timestamp: September 30, 2017, 12:12:51 am
content: Another vote for buying silicone wire and DIYing your own.FWIW, I've gotten mine primarily from eBay. For the small stuff, I go with 20AWG; the only 30AWG I use is solid core Kynar.

author: tooki
author_rank: Super Contributor
timestamp: September 30, 2017, 02:13:46 pm
content: Quote from: tggzzz on September 29, 2017, 05:28:09 pmYes, 24ga = 24 AWG. (ga = gauge, AWG = American Wire Gauge, which is very, very similar to British Standard Wire Gauge)Anyway, it’s just a nice size that I’ve used many times for thin leads — not so thin as to be hard to work with, but thin enough to be flexible (literally, and figuratively). 22ga is too thick for many Dupont-style crimp terminals, 28 is too thin for most.Also, bear in mind that silicone wire’s insulation is thicker than PVC insulation, so you may run into space constraints that you’re not used to, if you’re used to PVC. I found 24ga silicone to work very well with Dupont stuff.

author: tggzzz
author_rank: Super Contributor
timestamp: September 30, 2017, 04:14:08 pm
content: Quote from: tooki on September 30, 2017, 02:13:46 pmThanks.