Forum - Recent Threads

CT3679 Twin Lead Adapter, Probe Compatibility

baldengineer — Wed, 31 May 2023 15:35:04 GMT

The CT3679 Twin Lead adapter converts a 5 mm oscilloscope probe to a two-socket connection. You can either connect those sockets to header pins or use the included SMD grabbers to connect to small leads. While they obviously work well with Cal Test's own probes, they may also work with other 5 mm scope probes. But, as you can see in this Workbench Wednesdays Video, not all of them!

Compatible Probes

Multicomp Pro OW3200
Rigol RP2200

Not Compatible Probes

Rigol P6060
R&S RT-ZI10C Isolated Passive Probe
YPioneer P4100 100X High Voltage Probe

Obviously, this is not a comprehensive list. These are just the 5mm probes I have in my lab. Post your experience with the CT3679 below.

Purchasing

I recommend having at least one of Cal Test's probes since they fit well together. I recommend the CT3133RA. It's a 350 MHz probe. My testing shows you really only get about 90-100 MHz out of the adapters before they start ringing.

Remember, the "RA" at the end means the probe has the pin to indicate to the oscilloscope it is a 10-to-1 probe.

The CT3679 Twin Lead adapter is also available in the CT3288ARA kit.

Its part number ends in "ARA."
The first A means it includes additional accessories like the twin lead adapter.

Video

If you haven't watched it yet, there's a full video on the twin lead adapter, watch it here.

Microcontroller Dev Boards: What features do you like to have (or to add?)

baldengineer — Sun, 15 Jan 2023 15:56:39 GMT

A couple of weeks ago, I bribed shabaz (with coffee) to send me one of his Pi PIco Eurocards. As the name implies, these are a development board for the Pi Pico / RP2040. In the past, another friend sent me one of his all-in-one microcontroller development boards (pictured above). And I have designed a few boards that had development features on them. Besides those, boards like Adafruit's Feathers or even the iconic Arduino Uno could be considered dev boards. Last, historically, microcontroller manufacturers had elaborate evaluation platforms for their chips.

All of these points made me wonder: what are the features YOU want to see in a microcontroller development board?

If we use shabaz's Eurocard, some notable features are:

Headers for changing power source (external / Pi Pico / Programmer)
Integrated programmer/debugger (RP2040-based Xiao, in this case)
Prototype areas for through-hole and surface mount parts
SD Card
Button
LED
(and many more)

In addition to features, what tricks or tips have people learned when making a board like this one?

What’s an example of where you picked the wrong Op-Amp … and why?

baldengineer — Mon, 12 Dec 2022 23:10:33 GMT

I’m working on an episode about Op Amps and measuring some basic parameters. (For those like me who would rather measure something than go cross-eyed looking at a datasheet.)

Since there are more than a handful of op amps, I can imagine there are situations where people select one or re-use one without fully evaluating all of its characteristics. So, that got me thinking, what are some cases where you picked an op-amp for an application, but it was (clearly?) the wrong one… and why?

Bonus question: does anyone still use the ua741 … for anything?

What are some Multimeter Tips / Tricks / Unique Measurements?

baldengineer — Thu, 30 Jun 2022 03:08:43 GMT

While looking at my humble handheld multimeter, I got to thinking about different tricks for using a DMM.

For example, the trick to check the ammeter's built-in fuse or measurements like verifying if a BJT is blown.

What are some fun measurements you can do with a DMM?

What has been your experience with low-temperature solder?

baldengineer — Thu, 26 Aug 2021 01:10:03 GMT

Recently I found Chip Quik Sn Bi Ag Solder PasteChip Quik Sn Bi Ag Solder Paste. It is a low-temp alloy with Bismuth (and Silver.) When using hot air to solder parts, or during re-work, it makes the process go so much faster. It melts around 140C. It also does not appear to need refrigeration and has a long shelf-life. With all of those positives, I'm wondering what the downsides to using it are compared to more "traditional" solder alloys.

So whether positive or negative, what has been your experience when using "low temp" solder?

Mutual Inductor?

trehill01 — Sun, 22 Aug 2021 14:41:02 GMT

Is this a mutual inductor? If not, what is it and how does it work.

cnc laser cutting machine

ramjit*8 — Fri, 22 Nov 2019 22:07:14 GMT

I am a newbie and I am working on a project, Where by I have to engrave fine dots

on a form of acrylic sheet and cut it to my specs. Now the pickle, It has lots of cnc

and laser machines out there, I am looking at a few, And the following caught my interest

NEW-Carve CNC, I do not know if it would be able to do what I want, Can you help?

Bhim