Hi,

I have a strange and hopefully interesting situation. I have 4 lights on my front porch circuit. I recently installed these amusing LED "flame" simulation bulbs. They look pretty cool but the problem is, all 4 "flicker" at the exact same time with the same pattern. I'd like to insert some kind of delay at each light so they are somewhat offset from each other and thereby "flicker" in a more natural pleasing way.

I have no idea how to do this in an AC circuit, let alone at 120v levels. My only experience with this sort of thing is in small DC projects. Can someone tell me if there's a small relay or part that I can install in line to make this work?

Thanks,
Aric

 

Welcome to the forums.

There really isn't much you can do. Those new style LED bulbs are programmed thru a COB (chip on board) and if all the same part number.... run the same program so if they are turned on together they will look the same. The only way to look different is to have different startup times and even then they could still be the same.

I guess you could make up a small relay with time delay for three of the lights but where would you put it ?

 

Well different start up times for each is exactly what I'm asking about. Is there some kind of device I can put into the circuit at each lamp that would delay it's power up?

 

Interesting problem. Verify that if you turn them on one at a time (unscrew) that they are no longer in sync. If so need a simple time delay relay at a few of them.

 

Haven't used it but should be what you are looking for: https://www.amazon.com/ICM-Controls-.../dp/B01LYA0LJX

 

That's really cool. It just goes inline on the hot side I assume?

 

Could use a diode and resistor in series connected to a relay with a capacitor across it. The cap would take a split second to charge. It might take trying a few DC relays to find a winner.

 

It says 120/240 VAC on the housing in the picture though.

 

That one is rated for line voltage. Thinking it might not work with only a LED bulb as a load. Minimum 40ma - about 5 watts. ICM105 goes to 10ma - https://www.amazon.com/ICM-Controls-.../dp/B00441XZXK

 

This is a household 120v circuit. These are LED that screw into a regular, old fashioned bulb socket.

 

My guess is the circuits controlling the LED devices use a trigger from the zero crossing of the AC voltage. Therefore any delay would have to occur after the zero crossing detection and need to be adjustable to allow for multiple LED devices. At 60 cycles, a zero crossing can be detected every 8 milliseconds or 16 milliseconds. This is not much time to play with.

 

I wouldn't think they would trigger on a zero crossing or any other fixed point. At 60hz you wouldn't see the flicker just like you rarely see flicker on a TV or LED screen. The "flicker" seen from those bulbs is at most a few hertz.

 

I agree with Astuff that it would be worthwhile unscrewing and screwing the bulbs back in with the power on, just to see if just a different time shift of the bulb's cyclic pattern is enough to make it less objectionable.
It's possible you could also make it worse if it sequenced like a wave, or if you could make out a jumping pattern between the bulbs.
While I could envision more complex schemes of randomly dropping different AC cycles between the bulbs, or even having 3 of the bulbs supplied by its own inverter with a different frequency slightly off of 60Hz (so there could be no synchrony between the AC waveforms), that would obviously be getting way out of hand.
Also, this assumes that the device is using the 60Hz as a time base for a digital pattern generator, which seems a reasonable way to do it but it could be doing something else.

I think the easiest thing to do would be to just get similar size bulbs from different manufacturers because they have different ways of getting the flame effect.

 

We need to know the outcome of this experiment to make any useful suggestions. This will tell us if they have the same flicker pattern just because they came on at the same time, or if they are actually syncing to the alternating current waveform.

 

That time delay will need to be installed in some type of enclosure, such as the light fixture boxes.