Need suggestions for my DIY HV spark sniffer - Page 1
Forum section: electronics / projects

author: Chriss
author_rank: Frequent Contributor
timestamp: January 10, 2023, 03:00:55 pm
content: Hi!I'm dealing a lot with electronic repairing around all kind of modern engine with internal combustion.Many times I have a HV cable issue where are sparking between the gnd and the cable, which is at the end districting other sensitive devices or leading to a poor engine working conditions.So I come to an idea to make a device like a coil to pick up with my dso such of situation.I diagnose this kind of problem only in dark. So I can realize the sparks.And now I'm on my way to make a kind of probe for my dso.But before I run into a complicated task and project, I would appreciate from you guys, who are more in this field of EMI stuff to give me a handheld for start.Is it a good idea to use a coil?If yes, what should be the parameter?Are there any other way to sense these bad HV cable issue which are sparking in the dark?I need an idea what I can made at home like a DIY project.Any starting point I would really appreciate.Thanks.

author: jonpaul
author_rank: Super Contributor
timestamp: January 10, 2023, 03:26:07 pm
content: Oscilloscope, high voltage ignition, sparks...Regardless of the probe or techniques you will not get useful information and you will RISK BLOWING UP your scope.DON'T DO IT!99% of ICE ignition problems are bad spark plugs, bad wiring or bad ignition coil.Classic Auto neon ignition test lamps and sticks cost $3..20 and show the problems easily.Ask a car mechanic or go to any auto parts store.Jon

author: Chriss
author_rank: Frequent Contributor
timestamp: January 10, 2023, 03:30:15 pm
content: Actually I don't wish to directly connect the dso to any of the HV parts.I would like to receive over air with a coil the "sparks"...

author: TheMG
author_rank: Frequent Contributor
timestamp: January 10, 2023, 03:52:33 pm
content: That will be hard to do, since your pick-up coil or probe will show something even when the spark plug wire is perfectly fine. Most spark plug wires are not shielded, so there is actually quite a fair bit of leakage, both electromagnetic and electrostatic, around the cable even normally.But there is probably no need for all that complexity. Get a neon indicator lamp, connect one end to ground, then just sweep the other lead of the neon bulb along the spark plug wire. If there is insulation breakdown, it will arc to the neon bulb lead and cause it to light up. Simple and effective.

author: Chriss
author_rank: Frequent Contributor
timestamp: January 10, 2023, 07:01:07 pm
content: Is this what you mean?https://au.element14.com/cml-innovative-technologies/16-30hb/neon-lamp-wire-ended-t2/dp/1139250That kind of neon lamp?

author: Benta
author_rank: Super Contributor
timestamp: January 10, 2023, 11:16:57 pm
content: Spray the cable with Diesel starter. If the area catches fire, the ignition cable is defective.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 11, 2023, 08:29:13 am
content: Stick an LC and some LEDs on the end of a bit of light pipe or fibre- a phototransistor at the other. Add a broomhandle or bargepole if you have one.I have to say I prefer a an nitromethane/ ether blend with kosher salt (I love an orange flame) for spark detection. Diesel is so passe.Tip, make sure you light up your celebratory cigar first.

author: jonpaul
author_rank: Super Contributor
timestamp: January 11, 2023, 08:41:52 am
content: lights out, dark garage.Wait 15 minutes for eyes to dark adapt.run engine, look for signs of Corona, sparks on all parts,of ignition circuitNeon on stick one sided, detects HVSpecial series ignition wire, with neon, detects spark current.Any instrument or probe JUST NEAR a 15..40 kV fast rise igniton system ( especially modern electronic ignition) WILL pickup HV by capacitive coupling, and risk blowout of instrumentsUseless risk.j

author: Terry Bites
author_rank: Super Contributor
timestamp: January 11, 2023, 09:30:10 am
content: This works great as a spark detector. A French company by the looks of it.

author: buta
author_rank: Contributor
timestamp: January 11, 2023, 09:37:54 am
content: Use EMC current transformers / probes to check the discharge current:https://incompliancemag.com/article/measuring-breakdown-voltage-with-an-esd-simulatoredit 01: add spaces between two URLs

author: Chriss
author_rank: Frequent Contributor
timestamp: January 11, 2023, 11:31:30 am
content: Quote from: jonpaul on January 11, 2023, 08:41:52 amDark garage is my current method, and I can say I filtered out many times problems with these sparking stuff.The second method is to spray the HV region with water from plant sprayer.But, many times I need to use my dso, and I'm really afraid to kill it exactly cos of the HV "in the air".This was driving me in a direction to make some device to check before if there is HV out of the box but not to wait until it gets dark. :-)

author: jonovid
author_rank: Super Contributor
timestamp: January 11, 2023, 12:31:18 pm
content: cheap ultrasonic bat detector kit can detect the ultrasonic sounds from electrical arcing orAM broadcast receiver or basic audio amplifier with high gain input mic orold tape player old-cassette walkman, replace tape head with inductor add some coaxial cable.