Electronics > Beginners

Do I need a logic probe if....

(1/3) > >>

....I have an oscilloscope? Thanks

Yes. You will need two, one for yourself and one for your oscilloscope.

You only need a special probe if your oscilloscope has a logic analyzer built in or if the logic circuit is so sensitive that a normal oscilloscope probe causes it to stop working.

Well, I've been in this game for a few decades. I've had a logic probe the whole time, and have MAYBE used it three or four times.
Usually when I need something like that, I'll just toss an LED and a gate onto my protoboard to kind of make one.
At any rate, if you want one don't buy one!! You can easily make one out of less than a dollars worth of parts.

Go to Google ...
type in "logic probe" ...
click the "images" button ...
choose from several THOUSAND logic probe schematics.

( ... You will need two...   lol)

Appears to be down to personal preference. You certainly don't need one, so if you've a tight budget, get more important things first. The advantage of a logic probe over a scope is that it gives you a visual/audible indication of logic level, without looking up at the scope screen. Another advantage is that it can detect tri-stated outputs (high output impedance). It's also a lot smalle than a scope. Some people prefer them to scopes for logic work for these reasons. Personally I don't, in my opinion they might have been useful in the time of discrete TTL logic with hundreds of gates, but there aren't too many simple parallel signals in modern equipment. A scope shows the same and more (eg. noise), and is much more versatile.


[0] Message Index

[#] Next page

There was an error while thanking
Go to full version