scanlines caused by 3.3v trigger

[David Protter]

Hi all, 

Im using a 3.3v trigger line into an openephys daq to start recording on a v4 miniscope. We have a few scopes in the lab, and I alone am struggling with banding/scanlines than move up the sensor. 

The prevalence, incidence rate, and intensity are all sensitive to LED power (for most scopes, in the 16-24 range), sometimes using the EWL, but not gain.

I am the only person using a trigger, and it comes from a Raspberry Pi plugged into a 3-pronged 5v switching power supply. At times, Ive also noticed that plugging LED lights into the same USB bus as the DAQs, or having those lights run too close to the DAQs can also have a big impact on the prevalence of these artifacts. 

At the moment, I have put all USB lights on their own power supply, connected the switching power supply to the same power strip as the computer (so they share a true ground).

Anyone else have any ideas? 

Thanks!

Dave

[David Protter]

Well, I talked it over with our resident engineer, and decided to try using the daq power jack to power the scope. This required disassembling the case for the daq and moving a jumper, but it worked like a charm.

solved my own problem in just an hour!

[Federico Sangiuliano]

Hello Dave. One question. How long is the coaxial cable that you are using?

[David Protter]

Hmm, good q, it is probably about 3m (I believe we are just ordering whatever openephys normally ships, but I will double check.)