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Topic: DIY circuit test points, what do people use? (Read 402 times) previous topic - next topic

travis_farmer

i was browsing around eBay, looking for ideas for test points for my logic analyzer and oscilloscope.

mainly, i was tired of clipping the J-grabber onto a DuPont hookup wire, and touching it to just the right spot, or clipping it to a jumper wire with the insulation stripped a bit. i just like to test my circuits at various points to make sure things are as expected, after soldering them up. i figured, once i start milling my PCBs, i won't have as many jumper wires to clip to.

predominantly, i found the test points that are just a loop of wire, with a glass or ceramic bead for an insulator/spacer. i found them to be cheap enough, but not with the color-coded selection i wanted. it occurred to me, i could probably use small glass art/jewelry beads with a small loop of wire. but i am not sure if the beads have a big enough hole (anybody use them for anything?).

thoughts? ideas?

~Travis
Current Obsession: Ham Radio, and my CNC Router
Check out my website, i have my own forum on my hobby server.

larryd

I often use two connected pads, side by side, add and solder a loop of wire between the pads.
Or
Install a male header pin to a pad, use female header pins on the probes wires.

.
No technical PMs.
The last thing you did is where you should start looking.

travis_farmer

Hmm, simple but effective.

only reason i was thinking of the beads was for color coding, but i guess i can't imagine i would make a circuit big enough that i would have that many test points. perhaps i was overly complicating the issue (not that i ever do that :D )

Thanks for bringing my head back down to ground level ;)

~Travis
Current Obsession: Ham Radio, and my CNC Router
Check out my website, i have my own forum on my hobby server.

TomGeorge

Hi,
If I realise that a test point is going to be at the end of a resistor, not SMD, I lift the resisitor slighly off the PCB before soldering so a probe hook can slip under the resistor lead.
Or make a 360deg loop in the resistor lead before soldering it in, if enough room.
Or mount the resistor vertical, so the test point is the upper U bent wire.

If I'm using strip or vero board then its easy to make a loop out of the board with a bit of component lead offcut.


Tom.... :)
Everything runs on smoke, let the smoke out, it stops running....

travis_farmer

Hi,
If I realise that a test point is going to be at the end of a resistor, not SMD, I lift the resisitor slighly off the PCB before soldering so a probe hook can slip under the resistor lead.
Or make a 360deg loop in the resistor lead before soldering it in, if enough room.
Or mount the resistor vertical, so the test point is the upper U bent wire.

If I'm using strip or vero board then its easy to make a loop out of the board with a bit of component lead offcut.

Tom.... :)
Hmm, good tip, using a resistor (if available where a point is needed).

having a logic analyzer now, will make it easier to debug, but will take some extra schematic and board planning to make sure i have something to grab onto.

I used to bloat an Arduino application with various debugging code, but now i can see exactly what the direct result is, thus negating the need for most of the extra lines of code. :D
I do kinda wish the test leads for it were longer (6" of wire). but i can probably just get some Dupont crimp pins (male and female) and make a few extensions.

~Travis
Current Obsession: Ham Radio, and my CNC Router
Check out my website, i have my own forum on my hobby server.

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