AD3 Tracer generator fault above 1.3V?

[Luca71]

 

Hi!

I use the tracer with transistor tester adapter and also without adapter, to look the curve of a 1N4148 diode.

When I set the tracer below 1V (until 1.2V) all is OK!

 

But when I set more than 1.3V some relay click happen an AD3 and the trace is distorted.

This also happen with transistor.

 

It seem like something goes floating in the generator signal output.

Is my AD3 fault or it is the normal behaviour?

[attila]

Hi @Luca71

The capture seems legit, only the voltage measurement seems a bit noisier when C2 is in the high range, Vra > 1.25V
Notice that in the second screenshot you have unchecked Auto scale and you zoom in, which makes the noise more obvious.

[Luca71]

Thank you! for you answare.

The difference from the two screen below is the vra to: 1.25V versus 1.251V

When I change the voltage a relay switch in the AD3 occur.

This at 1.251V:

 

This at 1.250V:

 

Can be a defect AD3?

I dont thik that is noise, because in run mode both curves are stable.

[attila]

Hi @Luca71

C2 up to 1.25V (12.5mA) is in low range and above it switches to high range which provides lower resolution, more noise. The next sw version will switch at 2.5V

[Luca71]

Waveforms and AD3 are very very loveable product!

Thank you!