So in the development of the travel trailer we have redone- I put LED's for all of the outside lights- which looks great for the marker lights, and the brakes are nice and bright.
BUT.... when the running light are on, the elements that are in the 1157 bulb used for the running lights that when the brakes turn on or the turn signals are used, you can barely tell the difference.
These are the lights I have- https://www.amazon.com/gp/product/B07RY7DJR7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I supposed I could figure out which elements do what, but I was hoping that someone else has had this problem before....
Quick update- I asked here first thanks to the GRM mass volume of knowledge....
But I just saw that the bulbs I have don't actually run two sets of LED elements- it runs all of them. 75% vs. 100%-which is hardly a difference. Apparently Sylvania does build bulbs that have different elements for running lights vs. brake/turn. This guy did a great job showing this issue- https://www.youtube.com/watch?v=uoAQ-3mRlA0&ab_channel=PoorManMods
Since I have the incandecant lights, I'll go with them for now...
Odd problem, I must say.
That's a weird design choice. It seems like doing it that way as opposed to two separate circuits both adds complexity and makes a worse product.
Yorkim, Luyed, AutoGine, Vehicode, and Gkromzo are all brands that I have ordered. The Gkromzo seemed fine, but they get screaming hot and the melts the glue that holds the chipsets on the unit so I returned them.
Yorkim seems to do great. Brighter than stock but not anything to say wow about. Luyed was just dandy, but again, nothing super special. The Vehicode ones in the brake, turn, and backup lamps in the Branger will light a stadium. Those things are wicked bright.
Important side note. All of the ones above had good differentiation between dim and bright. I can't speak intelligently about the Gkromzo because they are in the backup lights of Kandy Van, so they only use the brightest circuit
LEDs are one of those things where I try to avoid the bottom end of the market or at the very least deal with a supplier who knows their stuff. SuperBrightLEDs.com was my go-to when I went to LEDs on the exterior of my street Miata. Now I'd probably use Diode Dynamics because that's what we sell at work :) They cost a little more but you don't throw things away because they don't work.
In reply to Keith Tanner :
So I asked superbright... specifically how to solve the problem, and they just suggested to add a resistor. I asked why, and the explanation was not all that clear- saying that it would allow to switch between the high and low contacts. My past experience with them made me think they would have a better solution- like one with separate circuits. But they didn't- just add a resistor to help it figure it out. Made no sense, and because of that, I'll look elsewhere.
As for Diode Dynamics- it's not clear that they have separate circuits for the two filaments, and they require a resistor. And they are 4x the cost of cheap ones that have the same features.
For that price, I can go through a lot of incandescent lights. And I'm quite sure that the two inputs are totally different circuits.
The purpose of a resistor is to mimic an incandescent bulb so the flasher works properly. It's not a great solution - makes a lot of heat - so ideally you'd actually modify the flasher instead.
I know that the 1157s I sourced from Superbright have very distinct high/low levels as do the Diode Dynamics. In my car, I modified the flasher so there are no resistors required. I think the different brightness levels are a separate thing from resistors.
Nothing wrong with adjusting LED brightness by using PWM. It's really simple and extremely common, and it allows for full light coverage at the lower brightness. Sounds like it was just implemented poorly in your cheap ones. That said, I know Diode Dynamics has "switchback" 1157s that are two different colors, so at least in that case they're doing something to separate them.
And yeah, price is not the reason to run LEDs when you can get replacement incadescents for a buck.
I have had some issues using 1157 LED replacements on older cars. The best solution I've found so far has been the Sylvania LED 1157's from the auto parts store and a high-quality electronic flasher module. The old style flasher modules don't play nice with the LEDs.
I run the LED 1157's because they're brighter, and on a 1964 Corvair convertible where there's no way to (tastefully) add a CHMSL and the stock STT lenses are only about 3" in diameter...you need all the light you can get.
In reply to Keith Tanner :
So my trailer is attached to a 2020 Escape- it can very much handle the LED's for the flashers. That's not the problem. If the resistor changes the system to run 50% on the running lights and 100% on the brake lights- that would be fine. But I can't see dropping the input voltage from 12V to whatever it ends up being changing the output to 50%.
No, there's nothing wrong at all changing the brightness- however it's done. But for the lights to be useful and safe, there needs to be a lot more differentiation than the lights I've seen do. That being said- I'm also interested that having a tiny PWM is cheaper than having a separate circuit.
On the Diode Dynamics webpage, they don't show a dual color 1157 light. But they, too, say that you need a resistor. I'd spend the buck if their solution was clearly better, using two circuits- but that's not clear at all on the webpage. They don't even describe the difference between running and brake lights.
Now that I've seen this issue, the issue is that nobody seems to be really explaining the problem very well. I may try the Sylvania lights, as they may work with my layout.
The resistor is for the flasher in most cars. You don't need it for varying intensity. I don't have it.
Tiny PWMs are cheap. I think the problem is that you've decided, after experiencing super cheap LEDs, that you need independent circuits when you don't. I think your blame is misplaced and you expect a piece of burning wire to work like an IC. Or vice versa.
If you want to know more, why not call DD? They're in the US and do their own engineering.
The dual color lights are called "switchbacks".
https://www.diodedynamics.com/led-bulbs/turn-signal-and-switchback/switchback-led-bulbs.html
Ah, I figured why the cheap LED maker suggested a resistor to increase the visible difference. It's probably to dim both levels by lowering the voltage, and it's a non-linear response. A workaround for a poorly designed piece.
That's not why SuperBright and Diode Dynamics are saying you need a resistor.
Keith Tanner said:
Ah, I figured why the cheap LED maker suggested a resistor to increase the visible difference. It's probably to dim both levels by lowering the voltage, and it's a non-linear response. A workaround for a poorly designed piece.
That's not why SuperBright and Diode Dynamics are saying you need a resistor.
So why is it they are telling me to run a resistor? The resistor was suggested by Super Bright LED, not some cheap fly by night group. I was hoping they had a product ready to go to replace the cheap lights I have.
BTW, the dual light that you found are for the font turn signals- amber and white- I need red/white, or white/white. This https://www.diodedynamics.com/led-bulbs/tail-and-turn-signal/1156-and-1157.html is the list of tail lights they market.
Is it really a problem that I expect LED lights that have two inputs have the same brightness differentiation as IC bulbs do? Again, cost is not a big problem- making a light work is. Forgive me that I'm a little gun shy when I don't see lights that clearly explain that there's a difference with running lights vs. brake lights. I'm not going to drop $60 if they are not clear on that.
Was SuperBright offering a solution for one of their lights that wasn't working, or for the cheap one with no differentiation?
I know the switchbacks aren't red/white, I was using them as an example of a light that may be constructed as you have decided they should be constructed. I really don't know if the DD lights are "dual circuit" or PWM, because it's never been a problem in my experience. Nor was it a problem with my SuperBright-sourced lights.
Again, I think you bought a super cheap product that wasn't well implemented, and you're extrapolating that behavior to all LED 1157s. Why wouldn't they have clearly differentiated brightness levels? It's like saying "this breakfast cereal doesn't say how much asbestos it contains, I am suspicious". 1157s are expected to have differentiated brightness levels, so why specify that this is the case?
In reply to Keith Tanner :
Why? because they don't explain the difference. It's a safety issue. Seems like a pretty obvious issue, seeing that I've now come across more than one University of Tube's video about it. Oddly enough, the only lights that appear to be real swaps are the Sylvania style. The multiple other ways companies put them together don't seem all that effective- either too dim or almost no differentiation (or both). It would be SO easy to advertise the lumens with the running light and another with the brake light. Even in the specs.
I asked superbright LED if they had a product that I could buy from them that would solve the issue, and instead of offering me one of their lights, they offered the resistor. I really just wanted to buy a bulb from them and be done with it.
If DD lights had the dual color for tail lights, I would consider them. They don't- just red. I sent them a note asking about light difference, and am awaiting a reply.
I had no idea, but apparently there is a requirement for illumination difference between the running lights and the brake/turn signals. And it's a pretty huge margin. I guess that should hardly be a surprise.... I work in a very different area.
And because of that, I'd risk buying the Sylvania bulbs over most others- since they build car bulbs.
So I got a reply from Diode Dynamics- their 1157 tail lights are the 75-100% set up, just like most others. And they didn't have any suggestions to make that separation larger.
(a side issue with them that I found this morning, Michigan requires that the license plate is illuminated with white light- the drivers side light is also my license plate holder- illuminated by the running light in the 1157. All of DD's tail lights are red)
In time, I'll probably try the Sylvania lights I can get at NAPA, as that design seems to be the only one I can find on line that is more like the IC lights in terms of brightness difference.
So, I've given this a little more thought since my hasty post above and I now totally get why they use a controller circuit and vary brightness rather than use more LEDs on the brighter mode.
All bright LEDs have a controller circuit because the need to be pulsed. If you look at an LED data sheet you'll see that they can only handle full current for a short amount of time. Yes, you can run an LED with just a current limiting resistor but it has to be at a much lower current, and therefore brightness, than if you pulse it. Since the replacement bulbs need a controller anyway why not light all the elements in both modes but at different brightnesses?
The most common issues with replacing incandescent bulbs with LEDs in automotive applications is that the LEDs draw less current preventing traditional bi-metallic flashers from getting hot enough to flash and confusing current detecting bulb sensing circuits so that they don't know that the bulb is on. The solution is to put a resistor in parallel with the bulb. This doesn't change the voltage to the bulb, or limit the current to the bulb but instead provides a draw on the circuit that mimics a conventional bulb.
I have no idea why SuperBright was suggesting that as a solution to alfa's problem. I suspect that it's because the person alfa was talking with didn't understand the question is is trained to suggest a resistor to solve LED bulb problems although t's possible that they're suggesting that you put it in series with the running light circuit to reduce the current and therefore the brightness in that mode.
Personally, I'd switch to a better brand that has a demonstrated acceptable performance like whatever brand Keith has in the video he just posted.
The ones in the video are part 1157-R45-T 1157 Red from Superbrightleds, purchased in 2013 for $25 each. That's all the info I have. But this discussion has certainly reinforced my feeling that this sort of product is one best purchased from specialists :)
It's recommended you use red bulbs in a red housing because otherwise you're just filtering out all the other wavelengths. If your lights are constructed so that it has a side window to cast white light, then you use white 1157s instead. Easy enough.
In reply to Keith Tanner :
Right, and in 2021, Superbright tells me that I need to add a resistor to make any of their work. While DD tells me they have little difference between the brightness.
So unless there's another specialist out there, neither of the ones I am aware of don't have the product other than the cheap LEDs. They just charge more.
Are you going to make me install a set of DDs and test them for you? Because we would not have added them to our product line if there was no visible difference between taillights and brake lights. We actually checked them out, I think I still have spots in my eyes from the switchbacks.
LED response tends to be non-linear in my experience. And it may not be consistent across different LEDs. So it is possible that the DD bulbs at 75% duty cycle are visibly dimmer than at 100%, which is not the case for the chips used in your other bulb.
Or just get some $1 incandescent 1157s and throw a spare in the glovebox.
In reply to Keith Tanner :
I don't doubt what you sell. But DD tells me that the 1157 tail light bulbs they have only separate the tail from full by 25% lumens. This is their words, and that's exactly how the cheap lights I have work. Up close, you can see it, or if you are paying attention. But I need something that grabs people's attention. More than one site shows IC's increase the light from the running to brake by 10x- which is very noticeable. DD sent me in their e-mail that the 1157's they sell on their website does not do that. Let alone they are just red.
And DD didn't tell me the duty cycle, they sent the lumens. I can post the reply if you want, but what they market on their website does not meet my needs.
