EEVblog #1016 - Crude Multimeter Overload Testing - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 15, 2017, 11:41:40 pm
content: Dave tests the Uni-T UT-513 5000V high voltage insulation resistance tester with the PIntek 15kV HVP-15HF HV oscilloscope scope to see if it's suitable for crude multimeter overload testing, with some spectacular results on the ANENG AN8008http://www.triotest.com.au/store/high-voltage-probes/662-pintek-hvp-15hf-high-voltage-probe-15kv-50mhz-x1000.html

author: Brumby
author_rank: Unknown
timestamp: August 16, 2017, 02:11:45 am
content: What do you mean no protection ....It's the open air GDT approach:(Great shot, BTW)

author: EEVblog
author_rank: Unknown
timestamp: August 16, 2017, 02:20:06 am
content: Quote from: Brumby on August 16, 2017, 02:11:45 amIt works, I'll give it that!

author: G7PSK
author_rank: Super Contributor
timestamp: August 16, 2017, 08:17:34 am
content: It's time to get a couple of microwave transformers and put them in series, that should let the smoke out of any meter.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: August 16, 2017, 01:53:27 pm
content: That evil laughter at the beginning is hilarious!Someone needs to meme that.

author: Brumby
author_rank: Unknown
timestamp: August 16, 2017, 04:54:32 pm
content: Quote from: hayatepilot on August 16, 2017, 01:53:27 pmNot a bad effort - but I think he still has a way to go to compete with the likes of Vincent Price

author: tecman
author_rank: Frequent Contributor
timestamp: August 16, 2017, 05:20:55 pm
content: After Dave's prior "endorsement" of the AN8008 I bought one. Not for the bench, but for kicking around the house, and using it at the car, etc. I have to say for the price it is tought to beat. Pretty solid, reasonably accurate, etc.Now Dave has crushed my enthusiasm for the cheap, little boy. I might have to put a fitting on it so I can purge it with SF6 for measuring those kilo-volts.paul

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 16, 2017, 07:38:06 pm
content: What the *** is the deal with the axis labeling on the scope? 3.96KV, 34.95966ms... Really?

author: Neilm
author_rank: Super Contributor
timestamp: August 16, 2017, 07:41:10 pm
content: Dave - no IR tester that is any good will switch in the voltage - it would stress the insulation especially older types of insulation. IIRC, a ramp rate of 3kV/s to 5kV/s is recommeded by manufacturers.

author: thm_w
author_rank: Super Contributor
timestamp: August 16, 2017, 10:34:30 pm
content: If you want to apply the voltage relatively instantaneously, put a knife switch or even a GDT in series with the insulation tester.GDT on-state voltage is ~20V so not much will drop across that.There is also the long wooden stick connection method..

author: EEVblog
author_rank: Unknown
timestamp: August 16, 2017, 10:37:33 pm
content: Quote from: PA0PBZ on August 16, 2017, 07:38:06 pmAnother one triggered

author: ocw
author_rank: Regular Contributor
timestamp: August 18, 2017, 08:34:44 pm
content: The UT512 and UT513 are meant for a non-lethal current output of 1.8 mA maximum. My UT512's actual "2.5 kV" output was measured as being 2,803 volts. I used it for testing some of my 16 uF 5,000 volt capacitors. It was fine for that. However, after the test the capacitor was still charged with short term high current capability. My first shorting stick safety test produced a loudPOP. I went to a resistor discharge after that.

author: SeanB
author_rank: Super Contributor
timestamp: August 18, 2017, 09:02:47 pm
content: Quote from: G7PSK on August 16, 2017, 08:17:34 amNeon sign transformers, though they do not give a great bang Andy style, but will arc over pretty much any meter. Arcs over CRT bases nicely though, and gives a good light show in the tube as well.Just thinking, what will happen if I use one, an appropriate diode rectifier and that 100n 10kV silver mica capacitor I have knocking around, and find some switch that might survive 10kVswitching a few times without detonation.