im building a logic probe for my digital electronics class. i have found TONs of circuits on the internet. many of them are quite complicated. im hoping someone could take the time to post a schematic that is as simple as possible but still has these features: ttl and cmos levels, high and low leds, and preferred but not absolutly neccesary, pulse detection. TY

 

Yours is a class assignment. We will not simply give you a circuit. This is because you will not be learning anything that way. You must make the initiative by posting your own circuit. Then the membership will then critique it.

 

Hello,

I made a TTL probe quite a while ago:
Project: TTL Logic probe.

It is upto you to convert it to Cmos.

Bertus

 

my post was a little misleading. its not an assignment. im building this independantly, just cause i like building things.

 

my post was a little misleading. its not an assignment. im building this independantly, just cause i like building things.

Well that's a horse of a different color. Anyway, the approach that Bertus took is the slickest I've ever seen.

 

the approach that Bertus took is the slickest I've ever seen.

I agree; Bertus, that's just plain clever!

 

can this circuit be easily modified for pulse detection as well?

 

Hello,

Did you have a look at my circuit?
As you can see there is a part for detecting high and low
AND a retrigable monoflop to make the pulses visible (even needle pulses).

In the circuit you posted the monoflop part is missing.

Bertus

 

can this circuit be easily modified for pulse detection as well?

smart way of implementing pin5 of the 555 timer!