Welcome to The PlanetChristmas Forums
Register now to gain access to all of the PlanetChristmas forums. Once registered and logged in, you will be able to create topics, post replies to existing topics, give reputation to other members, get your own private messenger, post status updates, manage your profile and so much more. This ugly looking message disappears once you have signed in.

Full Wave, Half Wave, No Wave?

24 posts in this topic

Posted · Report post

I have some LED icicle lights running the outline of the house and several LED C3 lights that I have in a large tree. Is there a way I can tell if they are full, half, or even no wave??? Not sure if there is a "no wave" but with my luck they are ;)

Thanks in advance.

Share this post


Link to post
Share on other sites

Posted · Report post

What type of lights? Bought them where? Most likely half wave if bought locally.

Share this post


Link to post
Share on other sites

Posted · Report post

If they are half wave there usually is a noticeable 'flicker" when you look at them.Just like SteveMaris said,if you purchased them from a box store more than likely they will be half wave.

SPaschall

Share this post


Link to post
Share on other sites

Posted · Report post

Half wave and full wave refers to the type of rectifier circuit used for LEDs. So if you have incandescent, you have "no wave". :cool:

Share this post


Link to post
Share on other sites

Posted · Report post

My test. Plug in and move them such as swing them around (doesn't take a lot of movement). The human eye can easily detect the nauseating flicker of half-wave in this manner. Caution: Careful if you are epileptic.

Share this post


Link to post
Share on other sites

Posted · Report post

Another way to tell I discovered the other night photographing mine. I was using a digital camera and held the shutter button down half way to focus. When I did that the lights were flickering in my camera display.

Share this post


Link to post
Share on other sites

Posted · Report post

Most of the lights I have are purchased at Home Depot.  I'm going to have to try some of the tips offered to see if I can tell if they are wave or not.  Going forward on any light purchases, should I buy full wave if I plan to use an LOR controller next year?

 

Thanks for advice and help!

Share this post


Link to post
Share on other sites

Posted · Report post

Yes if you plan on going to LOR next year try the vendor's on planet Christmas. I was lucky to check the classifiers very often. When some people move they sometimes downsize or sell everything. They also have easy ways to convert your half wave sets to full wave by a simple nightlight or a snubber.<br /><br />I currently have animated lighting but lord is the way to go if you have time or someone near you that uses lor.<br /><br />Full wave are a little more but cheap stuff is sometimes not that good and good stuff is not cheap. Try to do the preseason sales to if you can.<br /><br />Hope this helps.<br />

Share this post


Link to post
Share on other sites

Posted · Report post

LEDs have been known to have issues dimming so if you plan on getting into the animation world then make sure you are getting full-wave. That is one of the only "sure" ways of ensuring your LEDs will actually do what you want them to.

 

To save money: Plan ahead, buy during the off-season, buy in bulk (where applicable).

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

Actually, with a "snubber", they dim much better.  However neither Full or Half-wave dim as well as incandescents.   When reprogramming for LEDs, keep that in mind.  With incandescent you can do a 0-100% fade, but a ramp with any LED is at best 20-100% up to 40-100%.  Half-wave - without a "snubber" may have a fade of 99-100% (Off/On).

Edited by Tim Bateson

Share this post


Link to post
Share on other sites

Posted · Report post

Actually, with a "snubber", they dim much better.  However neither Full or Half-wave dim as well as incandescents.   When reprogramming for LEDs, keep that in mind.  With incandescent you can do a 0-100% fade, but a ramp with any LED is at best 20-100% up to 40-100%.  Half-wave - without a "snubber" may have a fade of 99-100% (Off/On).

 If you have an LOR Gen3 controller, they do actually dim as well as incandescents.  Why?  Gen3 not only has a built in "snubber" but they allow different dimming curves!!!!  This allows for the non-linear ramps needed to give a linear light output as expected by us animators.  I believe these curves (stored as xml files) allow up to 1000 different points on the curve, compared to just 255 with the previous generation of LOR controllers.  LOR also says they have a conversion utility (soon to be available according to the documentation) that allows you make your own curves to fit the brand of LEDs you have.  I use the ones sold by Paul at CDI, and when I put my LEDs, controlled by a Gen3 controller, next to my incans, there is very little difference.

 

Dennis

Share this post


Link to post
Share on other sites

Posted · Report post

Sounds very promising.

Share this post


Link to post
Share on other sites

Posted · Report post

Half wave dim just as well as full wave.

I don't know why people keep saying that.

I have every possible brand of store bought LED's and they all dim just fine, but ONE.

 

Martha stewart LED's, with three wires going into each bulb, that have capacitors built in. 

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

That's ironic Steve because all of the green LED lights I purchased for my large tree this year are Martha Stewart brand, which I bought at the HD.  Twenty strands of 50 count strings went onto the tree.  Sounds like if I go animated next year, I may want to change some things or just not animate the tree.

 

Thanks to all for the comments/suggestions.

Edited by Stefan

Share this post


Link to post
Share on other sites

Posted · Report post

That's ironic Steve because all of the green LED lights I purchased for my large tree this year are Martha Stewart brand, which I bought at the HD.  Twenty strands of 50 count strings went onto the tree.  Sounds like if I go animated next year, I may want to change some things or just not animate the tree.

 

Thanks to all for the comments/suggestions.

I have a bunch also that I bought my first year. I still use them, I just put them on bushes that I do not fade up or down. 

On and off seems to work fine...LOL

Share this post


Link to post
Share on other sites

Posted · Report post

Half wave dim just as well as full wave.

I don't know why people keep saying that.

I have every possible brand of store bought LED's and they all dim just fine, but ONE.

 

Martha stewart LED's, with three wires going into each bulb, that have capacitors built in. 

 

That's great that yours are working Steve.  Most people do have issues with this.  It is not just a perception,  The technical explanation behind why people have issues is because on how triac-based dimmers work.  They dim by turning on for only a portion of the sine wave that is delivered to your house.  An LED string with a half-wave rectifier already has half of that sine wave removed!  Imagine your controller trying to turn on your LED string on the portion of the sine wave that is removed by the half-wave rectifier.  :wacko:   This is what causes the flicker that so many people experience.

 

The entire sine wave is available with a full-wave rectifier.  Thus the LEDs can be turned on anywhere along the sine curve resulting in flicker free dimming. 

 

Hope this explanation helps some people understand the technical reason behind desiring a full-wave rectifier in the LED strings.

 

If anybody has any questions, shoot me message.

 

Dennis

Share this post


Link to post
Share on other sites

Posted · Report post

Do you have a picture of a half wave rectifier? 

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

I don't have a picture because I don't have any half wave LEDs and it would be very dependent on how the manufacturer packaged the rectifying circuit.  But here is a schematic representation and the resulting waveform of a half wave rectifier:

 

600px-Halfwave.rectifier.en.svg.png

        

And the same with a full wave rectifier:

760px-Fullwave.rectifier.en.svg.png

 

 

 

The circuits shown here may not be exactly what is in any given string, but do represent the input and output of these 2 types of rectifying circuits.

 

Let me know if you have any questions.

 

Dennis

 

.

Edited by Takoda

Share this post


Link to post
Share on other sites

Posted · Report post

The reason I ask is because I have yet to find a rectifier on any of the 100's of strings I converted to full wave. They have resistors on some, but no rectifiers. And in all the testing I have done, converting the strings did not change the way they fade at all. 

Flicker gone? Yes

Brighter? Yes

Fade up and down any different? Not so much 

 

 

Let me know if you have any questions.

Share this post


Link to post
Share on other sites

Posted · Report post

All of my LED's with 1 exception are all store/big box brand LED strands, all dim, fade up/down, and shimmer just fine.   No flicker, some have the wart on the wires, some do not.  The only time I have ever encountered the flicker effect is if I added more than 3 strands of the LED's to a single channel.  Up to 3 I have no issue, nor does it matter the LED count, most are 50 to 100 Count, I also have 2 spoois of 200 ct Lowes brand LED's and they work just fine too, even if plugged into each other on one channel.

 

Only time I've ever needed to add a C7 bulb to the LED strand is when I put more than 3 strands on a single channel, other than that, I haven't had any issue with LED's from Lowes, Wal-Mart, Target, K-Mart, Big Lots or Home Depot, however, I would not buy Martha Stewart LED or anything else with her name on it! 

 

And wether this is fact or not, I do not know, but I seem to recall reading somewhere that someone testing Martha Stewart LED's by fading them up/down, the strand they were testing caught fire!   Not something I'd want on my house or even near my display, even if I wasn't using LOR.  I would be too afraid to use them, thinking they may fail and burst into flame and burn my house down!

Share this post


Link to post
Share on other sites

Posted · Report post

That's ironic Steve because all of the green LED lights I purchased for my large tree this year are Martha Stewart brand, which I bought at the HD.  Twenty strands of 50 count strings went onto the tree.  Sounds like if I go animated next year, I may want to change some things or just not animate the tree.

 

Thanks to all for the comments/suggestions.

 

Do NOT dim Martha Stewart lights without a fire extinguisher handy.  The circuit they use to smooth out the flicker tends to literally explode quite violently/catch on fire when attempting to dim them.  This was not just an isolated incident but is proven repeatable.  The capacitors will blow their tops; beware of shrapnel. 

 

http://www.christmascarolina.com/forums/lights/2184-martha-stewart-flicker-free-led-strings.

 

 

As to not finding a rectifier in a half-wave string; each LED is a Light Emitting Diode.  Another name for Diode is Rectifier, so the LEDs are doing the half-wave rectification when they do the forward conduction.  The other half of the cycle they are blocking current flow and are not emitting light.  It's that alternating on and off that many people, including me to the point of nausea, see as the flicker.

 

Putting a bridge rectifier in front of that string means the LEDs do forward conduction twice as much (or if connected backwards, blocking twice as much) and the flicker is reduced considerably. 

 

We found a source of 1N4006 diodes (1 amp, 600 PIV) for 2 cents each, including shipping.  The most expensive part of the modification to full wave is the cost of heat shrink.

Share this post


Link to post
Share on other sites

Posted · Report post

Half wave dim just as well as full wave.

I don't know why people keep saying that.

I have every possible brand of store bought LED's and they all dim just fine, but ONE.

 

Martha stewart LED's, with three wires going into each bulb, that have capacitors built in. 

 

 

Happy for you; I can't spend much time at a display such as yours; the flicker makes me nauseated.  I'm not the only one.

 

Actually, full wave does dim slightly better than half wave due to duty cycle, but the difference is probably not measurable by most human eyes.

 

Anything with a capacitor in it usually doesn't dim well, and depending on what type of capacitor is used, they tend to go bad with explosive results.  At best they would hold the voltage up longer than desired causing slow dimming.

Share this post


Link to post
Share on other sites

Posted · Report post

Happy for you; I can't spend much time at a display such as yours; the flicker makes me nauseated.  I'm not the only one.

 

Actually, full wave does dim slightly better than half wave due to duty cycle, but the difference is probably not measurable by most human eyes.

 

Anything with a capacitor in it usually doesn't dim well, and depending on what type of capacitor is used, they tend to go bad with explosive results.  At best they would hold the voltage up longer than desired causing slow dimming.

I display such as mine has led's that have all been converted to FW using the same diodes you mentioned above. 

You also agree that the half wave lights dim similarly to FW lights.

That was the only point I was trying to make. 

Share this post


Link to post
Share on other sites

Posted · Report post

I display such as mine has led's that have all been converted to FW using the same diodes you mentioned above. 

You also agree that the half wave lights dim similarly to FW lights.

That was the only point I was trying to make. 

 

In that case, I could spend some time at your display.  Thanks for the update; my fault for misunderstanding.

 

yeah, they dim similarly but they tend to be different than incandescent.   But the light source is done differently, so that's to be expected.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

Our Three Rules

At PlanetChristmas we are always positive, family friendly and Christmas-centric.

Lots More Information

What Drives Over-The-Top Christmas Decorators?

It is all about making lifelong memories and family traditions.