Oscilloscope Picking up Massive amounts of EMI/switching from Riden 6018 PSU - Page 1
Forum section: electronics / testgear

author: barbaroja
author_rank: Contributor
timestamp: December 05, 2024, 06:50:06 am
content: Using a Rigol DS1054Z and wanted to do some low voltage stuff but could not in any way due to a high noise. Started disconnecting everything and found out the culprit was the scope sitting on top of a Riden 6018PSU (in its grounded metal case). Started moving things around, separated them and got it to go down but for space constraints, the power cables should pass parallel, very close one to another. Still managed to separate them like 60cm away.Questions:1. Would an EMI line filter work? For the PSU or I have to use for both the scope and PSU?2. Would replacing the SMPS 60V that came with the Riden PSU for a linear one help? I can put a linear one with a toroid on it (still got the Riden Buck converter switching when on, though). I may go for one of the Riden P models which are supposed to be linear and only have switching for its internal operation (not the output), anyways.3. Why the grounded metal casing is not enough? Both are grounded at the same main outlet.4. I see pics of people labs packed with gear one on top of another, without problems. What is the correct way to wire the bench?Note. The Riden PSU does not have to be booted or putting a voltage out, not even loaded. Just turning on the SMPS gets this noise on. The LED lights do a minimal amount of noise.Thanks

author: barbaroja
author_rank: Contributor
timestamp: December 06, 2024, 08:35:29 am
content: Kept reading and some inconclusive results came. Some say the toroid would pick up the switching from the buck. Some other more academic documents say they don't.Could not find too much info of people having the same issues or using EMI filters on scope mains input.Any input appreciated.

author: electr_peter
author_rank: Unknown
timestamp: December 06, 2024, 02:35:08 pm
content: You have identified internal SMPS unit in combination with Riden to cause significant noise. What do you want to do next? Next steps depends on answer to this question.If noise is bothering you, replace internal SMPS with less noisy one (these are of ~standard size) or turn it off.If you want to make current PSU less noisy, it is much more involved (in complexity, time, knowledge and resources) task.

author: kloetpatra
author_rank: Regular Contributor
timestamp: December 06, 2024, 04:23:43 pm
content: Looks like common mode noise to me. However you described your setup not in enough detail to be sure.For that case I recommend thisHe also made a different video how to modify the PSU to reduce noise.

author: Ioannis
author_rank: Newbie
timestamp: «Reply #4 on:Todayat 01:33:18 pm »
content: I have the exact same problem with Riden 60V, 10A power supply.The problem seems from the 230Vac to 65 Vdc converter and not form then Varable regulator itself.The EMI is very strong and affects many devices in the lab. Had almost to throw away an amplifier due to this, only to find out it was the Power Supply the culprit.I also consider to replace the crapy converter with a transformer and a classic bridge/cap combo. If anyone has an alternative to that converter please reply.Ioannis

author: nctnico
author_rank: Super Contributor
timestamp: «Reply #5 on:Todayat 01:46:45 pm »
content: Rule number one: only use linear power supplies for electronics R&D work.