magik Posted November 1, 2023 Share Posted November 1, 2023 Hi there everybody, names ''magik'' and i've just joined this site. Did'nt know which forum to choose so hopefully i will reach somebody who can help me. My question is, I have bought from ebay a pack of 10 led striplights without resistors. When i connect them up to a correct power scource, a transformer set at 3volts, they wont light up. i've connected them with the correct lead to the positive but they will not light up. I've even connected them with a resistor and the other way round but still they will not light up. BUT when i put my finger on the actual strip light itself they light up. IT seems as though my body is acting as some kind of earth. Now i also have a set of these lights taken from my old layout which definately work and the same thing happens. What can i do to sort this out please? PS I also have other lights such as yard lamps which work perfectly well without a resistor. I have tried to contact the seller of these lights but he has failed to reply to my requests for help. Any help will be gratefully received. Thank you Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted November 1, 2023 RMweb Gold Share Posted November 1, 2023 Can you add a photo, or link to the eBay entry so that we have a better idea what you’ve got? Paul. Link to post Share on other sites More sharing options...
RMweb Gold LimboBrit Posted November 1, 2023 RMweb Gold Share Posted November 1, 2023 If the LEDs are connected in series you will need more than 3V for them to light up. As 5BarVT says, I think we need more information. What documentation was included? Maybe a specification of schematic? David Link to post Share on other sites More sharing options...
Michael Hodgson Posted November 1, 2023 Share Posted November 1, 2023 Confused as to what you have got and what you have done. If you have applied too high a voltage to an LED without a resistor in circuit you will have burned it out already. I have some cheap LED lights on a long sticky tape under my kitchen units for workstop lighting - they are basically arranged within the tape as groups of several LEDs in series (so each group requires a higher voltage to operate), possibly also some SMD resistors built in, powered by a wall wart to give the right DC voltage and these groups then repeat in parallel along the tape. That tape when worn will react to being touched because the supply wiring runs along the tape and it can break, and I find touching the tape can cause the lights to flicker because the wiring within the tape is making/breaking continuity. If you are use single LEDs as signals or to illuminate a building or similar, you will need a resistor whose rating will depend on the voltage you decide to run it from. Link to post Share on other sites More sharing options...
brossard Posted November 1, 2023 Share Posted November 1, 2023 I put LEDs in my Heljan Gresley coaches: There's a push button switch in the gangway and a 3V battery on the bulkhead. All included in the kit. I don't recall a mention of resistor, perhaps integral with the LED strip. Showing the switch connection. Lights are very bright. I painted them yellow to tone down. All buttoned up and a nice effect. Caveat, this is 0 gauge but should be the same for 00. The LED kit I got is from Layouts4U. I chose the pushbutton switch but there is a motion sensor as well. John 1 Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted November 1, 2023 RMweb Premium Share Posted November 1, 2023 When you say you "When I connect them up to a correct power source, a transformer set at 3volts, they wont light up". Exactly what power supply is this? Also how did you determine that it is 3V and is it 3 Volts AC or DC (with some sort of rectification built in)? Unless it is a regulated 3 Volt DC power supply, you run the risk of destroying the LEDs, if you haven't done so already. Hopefully you have a multimeter, to do some proper tests, rather than relying on labels. Link to post Share on other sites More sharing options...
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