Topic: Anyone using 24 LED 1157's ...

[MRieck]

 They should be bright enough with the benefits of less draw....

[csendker]

I've changed all of my idiot lights to LED - VERY bright now - and all of my gauge lights - kinda DIM now - but not anything else.  But it has been done --> http://www.sohc4.us/forums/index.php?topic=2894.msg112#msg112

Watch your blinker/winker controller, the mechanical ones don't work with LED's, gotta go electronic.

[MRieck]

I've changed all of my idiot lights to LED - VERY bright now - and all of my gauge lights - kinda DIM now - but not anything else.  But it has been done --> http://www.sohc4.us/forums/index.php?topic=2894.msg112#msg112

Watch your blinker/winker controller, the mechanical ones don't work with LED's, gotta go electronic.

I did a search before I posted and I think I saw the one on gauge lights. I'm thinking brake light only so no problems with flash rate. I run Kellerman rear signals on my busa which, though, a single LED, incredibly bright. Needed resistors though. I just think at traffic lights the 24 LED's would be plenty bright with minimal draw with no need for any resistors.

[csendker]

Brake/tail only should be no problem, and if it's not bright enough you can always go back.  If you look to the turn signals and want to save power, chuck the resistors and go with the electronic flasher.  If you don't care about power draw, either will work - resistors & mech flasher - or - no resistors and electronic flasher.  Personally, if/when I go further with LED's, I'll be going the electronic route.  I have too much extra resistance with an old harness and dirty connectors, I want to save as much juice as possible.  Of course, I should also be on a crusade to clean up all those crappy connectors too, but that's another story.

[MRieck]

Brake/tail only should be no problem, and if it's not bright enough you can always go back.  If you look to the turn signals and want to save power, chuck the resistors and go with the electronic flasher.  If you don't care about power draw, either will work - resistors & mech flasher - or - no resistors and electronic flasher.  Personally, if/when I go further with LED's, I'll be going the electronic route.  I have too much extra resistance with an old harness and dirty connectors, I want to save as much juice as possible.  Of course, I should also be on a crusade to clean up all those crappy connectors too, but that's another story.

I hear you. There are electronic flash units that let you choose between 4 flash rates etc. I'd certainly go that route too!

[csendker]

Speaking of flashers, FYI: Bodi just posted this nugget --> http://www.sohc4.us/forums/index.php?topic=10598.msg99658#msg99658 which points out that mechanical flashers start 'on' while electronic ones typically start 'off'.  No problem while turning at a red light, but may be an issue when indicating a lane change.

[Green550F]

Electronics lesson anyone?

Flashers began as a bi-metalic switch. they are constructed with a strip of two metals fused together. The metals have different rates of expansion as they heat up. The more rapid expansion of one of the metals  causes the fused set to curl around the slower expanding metal. So, initally the contact between terminals is by default, as current flows through the circuit the bi-metal strip heats until the flexing of the metal causes it to break the circuit. The open circuit stops current flow, the strip cools down, remakes contact and the process repeats. This is why mechanical flashers are on in the initial state.

Electronic flashers may switch the output from either initial on or off. it is common to design circuits to NOT draw power in the event of failure of timers or other control circuits. This is why most electronic units begin in an off state.  It is also important to note that some solid state relays will typically fail in the shorted state. This isn't a big issue for lighting, but if you are controlling a heater or motor, failing ON is not a good practice. In such applications a mechanical kill switch is usually added as well.

[Bodi]

The main problem with any LED 1157 replacement for the stock tail/stop lamp is that they tend to be way too dim for daylight use. The stock system uses the reflector to fill the reflector/diffuser platic cover with light, and it's mighty effective. The LED cluster is not very large in comparison and even those that point LEDs sideways to use a reflector don't work very well.
The other problem is that few replacement LED units have any license plate lamp function. That's required by law: whether the stop light is bright enough is a judgement call but having no license light can get you a ticket without any room for argument.
I tried several LED 1157's bought at auto parts stores, all were way too dim for me to risk as a stop lamp. This was 2 years ago and maybe they are brighter now though.
I am using a Ledtronics AUT1157M and it's fine at night and accpetable - but marginal - in sunlight, plus it has license plate lighting. This admittedly expensive unit is WAY brighter than any of the cheaper ones I could find in auto stores.
I'm working on a custom LED array for my tail lamp, with a circuit board that will replace the innards of the Stanley HM16-RC and hopefully be very visible in daylight (and a bit blinding at night).

Flashers: 2-wire electronic ones will start OFF; they charge a capacitor through the light filaments to power the timer circuit and the switching relay. If they started ON with the relay closed, there would be zero volts across the 2 terminals and no way to power any electronics to tell the relay to open.
2-wire electromechanical timers always start ON as explained by Green550F.
3-terminal ones with a ground terminal have power available when the turn signal is activated whether the lamps are on or off, and usually start ON whether electronic or electromechanical. Some still start OFF, I don't know why they would design one that way.