My first DT830D current mode spark - Page 1
Forum section: electronics / general

author: kalel
author_rank: Frequent Contributor
timestamp: September 23, 2017, 06:52:45 pm
content: While measuring the voltage of a battery, I managed to forget the probe in 10A current only position, and of course the probes sparked briefly. The short circuit didn't last long as the reflex is to move the probes away as soon as possible.The DT830D used seems to be intact. I haven't yet looked inside. There's no fuse in this one, but some versions do have a fuse.Just sharing the experience. It's actually the first time this happened, but I haven't very frequently measured current before.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 23, 2017, 06:57:59 pm
content: I've done something similar. Did not realize LCD driver voltage was in the kv range. I put the probe on the HV side of the transformer, got sparks, the meter beeped briefly and thankfully I did not release the magic smoke. I was not brave enough to try my scope, even though my HV probe can go up to 3kv.Also got a nasty shock off that driver. First time I get a shock that actually leaves a flesh wound. I was impressed!

author: kalel
author_rank: Frequent Contributor
timestamp: September 23, 2017, 07:00:50 pm
content: Quote from: Red Squirrel on September 23, 2017, 06:57:59 pmYes, that seems much more problematic than a battery. Is this a huge LCD that has such high voltage?

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 23, 2017, 07:27:26 pm
content: Big Clive always emphasizes moving the test lead out of the current jack after the measurement to avoid unpleasant surprises. I made that mistake nearly 15 years ago measuring a PC power supply with a cheap Harbor Freight, can still see the scar where I got burned by the test lead.

author: kalel
author_rank: Frequent Contributor
timestamp: September 23, 2017, 07:30:53 pm
content: Quote from: NiHaoMike on September 23, 2017, 07:27:26 pmYes, those versions may even have a fuse? Quite right, care needs to always be taken. I also don't use the test leads that came with the meter, but I'm not sure that would make a great difference in my (relatively safe) instance.

author: dmills
author_rank: Super Contributor
timestamp: September 23, 2017, 07:35:41 pm
content: Quote from: kalel on September 23, 2017, 07:00:50 pmLCDs don't run anything near those voltages, but a back light inverter for running CCFL backlights, can! Those things tickle!Regards, Dan.

author: Beamin
author_rank: Super Contributor
timestamp: September 23, 2017, 08:12:08 pm
content: I have never put the probes in amps and measured volts. I have also never lost my keys or wallet. But tomorrow I will lose my wallet and keys at the store buying a new meter to replace the one I forgot to put back in the proper socket.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 23, 2017, 08:46:14 pm
content: Quote from: dmills on September 23, 2017, 07:35:41 pmYep it was the backlight driver I was playing with not the LCD itself. Basically I was trying to see if I can repair a monitor from work, as they are too cheap to buy us more (they finally did recently though!) but they will replace ones that break and they never pickup the broken ones. So I was just doing basic steps like checking if the cable to the light is loose and when I pushed on it to see if it was tight, it arced right through. Zing! Smelled lovely. A hint of ozone and burnt ginger skin.