Agilent E3610 Spikes? - Page 1
Forum section: electronics / testgear

author: echen1024
author_rank: Super Contributor
timestamp: September 18, 2013, 01:42:25 am
content: When I hook my E3610 up to the scope, and turn it off, I always get this large spike in voltage. This happens with or without the load.Picture 1 is without load:Picture 2 is with a 22 ohm load:All testing was done at what the power supply said was 5 volts. Can anyone explain this strange phenomenon? Is there truly a spike or is this just noise?.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 18, 2013, 04:51:06 am
content: Same here ...

author: Unknown
author_rank: Unknown
timestamp: September 18, 2013, 05:05:30 am
content: Did you exclude the possibility that it's a common mode signal by connecting probe ground and tip to the same point?

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 18, 2013, 05:12:26 am
content: Heythank you for that point , But 110V at 200kHz ...

author: Unknown
author_rank: Unknown
timestamp: September 18, 2013, 06:41:44 am
content: Is it grounded at the wall socket?

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 18, 2013, 07:30:51 am
content: the E3610 - groundedthe scope - groundedcan that loop cause 110V spikes ?thank you

author: Unknown
author_rank: Unknown
timestamp: September 18, 2013, 07:32:57 am
content: Not likely, especially since the E3610 output is floating. How large was the common-mode signal?

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 18, 2013, 07:54:12 am
content: okay , seem like I actually meant 11V( Yes . the probe attenuation was 10:1 from my last use ...)

author: echen1024
author_rank: Super Contributor
timestamp: September 18, 2013, 02:10:05 pm
content: Curse you and your Agilent scope. However, the E3610 is isolated, and I repeated it multiple times yesterday. It seems like I get the spike if I push the power button a certain way, and that my probe and the scope was set at x10 attenuation. I smell

author: FrankBuss
author_rank: Unknown
timestamp: September 18, 2013, 03:54:52 pm
content: That's in the microsecond range. Could be anything, including induction. There is a garage motor near my lab and everytime it turns on I see such spikes. Did you try to turn on the PSU with the scope probe just shorted to ground and not connected to the PSU?

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 18, 2013, 04:36:00 pm
content: HeyIt seem like you are spot on

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: September 19, 2013, 02:40:02 am
content: If you try connecting it with coax as shown on photos do you still see the spikes? This is how I connect my my PSU, I figured I got linear PSU with good ripple characteristics therefore I should try to use coax to keep it quiet all the way down to DUT, or oscilloscope in this case.

author: echen1024
author_rank: Super Contributor
timestamp: September 19, 2013, 02:46:32 am
content: Ahhh. That might be the reason. Thanks for all the help guys!

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 19, 2013, 09:22:41 am
content: HeyYes I actually connected it via coax , all the above pictures are result of using coax ,only the last one is when the probe was shorted to the crock clip and to the negative of the supply , perhaps that loop reacted to the electro-magnetic fields produced by turning of an on the supply ?thank you

author: echen1024
author_rank: Super Contributor
timestamp: September 19, 2013, 05:50:41 pm
content: That confirms my suspicion that it was just noise, due to the fact that it is a very short time, less than a microsecond.

author: bingo600
author_rank: Super Contributor
timestamp: September 19, 2013, 06:02:20 pm
content: Quote from: Alexei.Polkhanov on September 19, 2013, 02:40:02 amWhere did you get the Coax to BNC adapters ?I'm a bit worried about ebay quality ....Is that a 50 Passthrough termination on the Scope end ?TIA/Bingo

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 19, 2013, 08:45:42 pm
content: Heybingo , I don't know where he got he's , but mine are pomona and same result ..

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: September 20, 2013, 05:26:23 am
content: Quote from: bingo600 on September 19, 2013, 06:02:20 pmI think I got everything from DigiKey or Newark, not sure exactly. I does have white teflon insulator inside by looks of it if this is what you worry about.Yes it is 50 ohm pass through - TEI 14949 TNA2-50. I use it mostly with my differential probe cuz it has 50ohm out. It is 1W terminator so I could not exceed 6V out on PSU. I improvised because without the terminator PSU keeps sloooooowly 'discharging' into 1Mohm input of oscilloscope for 20 seconds or so.Model of PSU in my case is E3630A. It is different from E3610 - it has no adjustable current, 3 outputs with +-20V and 6V and adjustable tracking ratio. I use it almost exclusively to power up OPAMP circuits. Looking at specs I see that Is E3630 has slightly better (1.5mV peek vs 2.0mV) comparable to 3610 but otherwise they should be similar.I removed the terminator, set trigger 200mV above 6.6V that were set on PSU and after turning it on and off about 25 times I got something that looks like noise in discussionThat is without probe - straight coax and no terminator.