I made a "shop lamp" out of an LED strip and power supply. When I plug it in there is a 1-2 second delay before the lights are powered up. Do some transformers have a shorter delay than others?

shop light

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    I just don't feel your pain, I guess. Is a 2 second turn-on delay (if it's even that long) really cramping your style that much???? Beats half an hour waiting for ice-cold fluorescent bulbs to finally make it to full brightness by a few miles...
    – Ecnerwal
    Mar 13, 2015 at 1:20
  • @Ecnerwal ... I feel your pain there ... I have that problem with my fluorescents in the garage in the winter time. I've been thinking of doing away with them and going to a large amount of LEDs to make up the light. Mar 13, 2015 at 13:30
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    Well--I have LED bulbs throughout my house that turn on instantly. Mar 13, 2015 at 14:35
  • The other issue is that when I turn on my light, I lose all my radio reception. I'm hoping a higher-quality transceiver would address that problem as well. Mar 13, 2015 at 14:36
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    It's not a transformer causing the delay. Likely a capacitor charging or an SCR waiting for voltage to stabilize before letting power out to your LED's. Jan 1, 2016 at 15:59

2 Answers 2


The more 'electronic' a power supply, the longer it takes to start up. I had this nuisance in my pantry, where I only need light for a few seconds, so I don't want to wait another few seconds every time. I also have a VERY high current demand from a lot of LEDs in total.

I used a sealed lead acid battery on a trickle charger, and a relays. Battery is on common. NO is connected to LEDs. NC to a trickle charger.

Yeah. I'll have to replace the battery when it goes out. Beats waiting for a power supply to ramp up.

Long term, I think I'm going to make a service grade (100-400A) 12/24/48v DC bus for the house, with capacitors for buffering.

You might try a very simple 120vAC to 12vAC transformer (assuming thats your LED's voltage) with a rectifier and capacitor in some enclosure. You're building electrics at that point, so test, and include fuses, etc.


There are fast-start power supplies, and those which are less fast. The latter tend to be less expensive as well so paying more might get you faster response. Or might not.

I have an LED-equipped light fixture in my living room, about 300W-incandescent equivalent, which starts instantly and is dimmable. It cost me about $300 just to put those bulbs into it.

But yours is what it is, and the only way you'll improve it is to replace it -- which means finding a way to return it, or selling it off to someone else who's willing to tolerate the pause, or learning to tolerate it yourself. Wish I could tell you otherwise, but...

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