Will Rigol DS1000 series run on modified sine wave? - Page 1
Forum section: electronics / testgear

author: Br0ski
author_rank: Contributor
timestamp: June 05, 2014, 08:06:58 pm
content: Hello all,Searched around the forum a bit and could not get a complete answer to this question.I have a Rigol 1102E (100 Mhz) and I understand it's designed for 120v pure sign wave power.But I want to take this thing mobile (mostly car measurements </= 12v) and I want to run it off the Duracell 600 mobile power station. Has a deep cycle battery, and runs a 400wmodified sine waveinverter.http://www.duracellpower.com/backup-power/power-packs/powerpack-600.aspxI also want to run it off the 500w Energizer Power Inverter tied to my car battery.http://www.energizerpower.com/inverters/EN500.phpSo I want to know if anyone has any first hand experience with this?What possible hazards would happen?Will the built in fuse be enough to save this thing if a spike happens?If you have experience: How many times have you run it off a modified sine wave inverter?Does the modified sine wave effect the measurement?Does the modified sine wave have long term damage to the test equipment?Thanks,Br0ski O0@Br0ski47

author: Lightages
author_rank: Unknown
timestamp: June 05, 2014, 09:08:45 pm
content: It should run just fine. It certainly won't blow up trying it.

author: Br0ski
author_rank: Contributor
timestamp: June 06, 2014, 10:00:07 am
content: I called Saelig -www.saelig.comThey said it was a delicate piece of test equipment so a big N.O.I called Rigol USA, Ohio -www.rigolna.comThey said they have hooked it up to a cheap Walmart inverter and a backup battery during a power outage."It ran fine." - ChrisI can only assume it was a modified sine wave.Anyone with first hand knowledge?Br0ski@Br0ski47

author: AintBigAintClever
author_rank: Regular Contributor
timestamp: June 06, 2014, 10:13:15 am
content: First thing the PSU's going to do is rectify and smooth the incoming supply anyway. It'd be interesting (maybe?) to see what the incoming rectified-to-DC rail looks like when fed by AC, "pure sine", "modified sine" and DC (which you may be able to tap out of your inverter's own HVDC rail).Watch out if tapping the inverter's DC rail though, they can take a while to discharge. I fitted a neon warning/power indicator to mine which brings it down to safer levels fairly quickly.I don't know what effect, if any, modified sine or DC would have on any input chokes ahead of the rectifier. I've seen a CFL driver with a single-winding inductor in series with the mains supply. Double-winding (both supply sides) would cancel out, but single winding = electromagnet?(guess who needs to learn about inductors properly :p)

author: wraper
author_rank: Unknown
timestamp: June 06, 2014, 11:00:39 am
content: Should work. However there might be noticeable noise added to measurements as this modified sine wave contain a lot of higher harmonics.

author: Rigby
author_rank: Super Contributor
timestamp: June 08, 2014, 04:25:16 am
content: Regular wall power is far noisier and dirtier than people assume. It will run fine on an inverter. You're gonna get enough noise on the leads that power condition won't be a huge factor, I'd bet.Scopes use switching supplies, anyway. Doesn't matter a lot how noisy the mains are.

author: MarkL
author_rank: Unknown
timestamp: June 09, 2014, 03:35:43 pm
content: "Modified sine wave" is a marketing term. It's a positive and negative going square wave, plain and simple. See photo below. (This is a Trace "modified sine" inverter - sorry I don't recall which model anymore.)The high dV/dt on the edges of the square wave creates high instantaneous current spikes through the input stage of switch-mode power supplies. Most supplies can take it, but some can't.I, for one, would never connect anything I care about to a "modified sine wave" inverter. Be kind to your equipment and get a true sine inverter. They're not as expensive as they used to be. If you're looking for suggestions, Samlex makes well built and reasonably priced ones.

author: dp
author_rank: Contributor
timestamp: June 09, 2014, 08:40:57 pm
content: Quote from: Rigby on June 08, 2014, 04:25:16 amIndeed. Mine is a fairly modified "sine" wave.

author: tautech
author_rank: Super Contributor
timestamp: June 09, 2014, 10:12:37 pm
content: Quote from: Rigby on June 08, 2014, 04:25:16 amI would agree.Understand how a SMPS works, it rectifies mains, charges a cap, switches that voltage at 20-50 KHz in a controlled way(pulse width modulation) to manage power input/output requirements.And the input mains conditioning will also mask some noise.All of the irregularities should be negated/smoothed before the switching stage.ANDMost scopes can be powered with 100-240 VAC @ 45-400 HzIf DS1000 is spec'ed similar....no problem IMO

author: saturation
author_rank: Super Contributor
timestamp: June 09, 2014, 11:19:35 pm
content: In general, most any SMPS will run well with modified sine wave supplies. The bigger concern using a scope I see is your inputs picking up more noise radiated by the supply to your surroundings [ such as if you operate it inside a car] and that the scope likely is not earth grounded, again if used inside a car.