Universal LED Tester from a Light Bulb. Is that safe? How does it work? Solved - Page 1
Forum section: electronics / beginners

author: t1d
author_rank: Super Contributor
timestamp: March 06, 2024, 01:45:15 pm
content: I saw a YouTube video, where the builder adapted a working LED light bulb into a universal LED tester. All he did was remove one LED and solder on two probes in its place. Then, he used the probes to inject current into faulty boards, for troubleshooting.Is that safe? What troubles (other than electrocution) might be encountered?How does it work? I imagine it is just a self-adjusting current limiting power source...Thanks for the education.

author: Ian.M
author_rank: Super Contributor
timestamp: March 06, 2024, 01:58:14 pm
content: What do you mean *other* than electrocution? To anyone somewhat sensible, using a non-isolated power supply for this sort of stuff is an unacceptable safety risk. Also, a rig like that can put out far more voltage than the reverse voltage rating of most LEDs so a moment's inattention or ambiguous markings could result in you destroying the LED you are trying to test, or other parts connected to it.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 06, 2024, 02:09:25 pm
content: Quote from: t1d on March 06, 2024, 01:45:15 pmYep the moment I read the original post, I thought "that is a dumb idea".Never wise to use something that normally works of of mains voltage, and is not meant for supplying a safe low voltage, to rig it up as some testing device for checking low voltage electronics. Touch the probe that leads to the live mains wire and your hair might touch the ceiling.People on youtube do al sorts of crazy things just to get a view.

author: Jason Henry
author_rank: Contributor
timestamp: March 06, 2024, 02:13:52 pm
content: While using a modified LED bulb as a universal tester can be a creative solution, it may pose risks if not done properly. Potential issues include damaging circuits, inaccurate readings, and the absence of proper current limiting. Caution is advised, and using dedicated testing equipment is recommended for safety and accuracy.

author: t1d
author_rank: Super Contributor
timestamp: March 06, 2024, 02:36:11 pm
content: Thank you for your replies. Obviously, I had concerns. That's why I posted the question. I appreciate your efforts to help me and the others that may read this thread.

author: Simon
author_rank: Unknown
timestamp: March 06, 2024, 07:40:32 pm
content: Quote from: t1d on March 06, 2024, 01:45:15 pmSorry given that electrocution is on the list and would take the top place do you need to go further?It's impossible to answer without looking at a specific bulb. It's basically a bad idea.

author: CaptDon
author_rank: Super Contributor
timestamp: March 06, 2024, 09:14:32 pm
content: Dumbest Idea I have seen posted in a while. A 9 volt battery and 1K resistor would be better by far!!! And by the way, 50% of the stuff I see on YouBube is idiotic, impractical and dangerous. For instance, all of the Free Energy videos!!! Biggest fools since AudioPhools!!!

author: t1d
author_rank: Super Contributor
timestamp: March 07, 2024, 08:04:40 am
content: By posting the question, I was not endorsing the device. It was a genuine question, to gather information. I will mark the title as "Solved."

author: p.larner
author_rank: Frequent Contributor
timestamp: March 07, 2024, 12:25:35 pm
content: Why even bother with this unless your after a darwin award,was it some aisian guy in sandals called inventor kr or some other content maker who spits out these nonsense vids by any chance?.