Does anybody really know what ever happened to sequential turn signals?

Just because the kits are on the market doesn't mean they can legally be used. Vehicle deign standards will usually not permit "gimmicky" signals such as this because they are "unusual" and attention getting. Following drivers are more inclined to stare at the signal rather than keeping their mind on what the meaning of the signal is. They tend to be more of a distraction than a simple indicator which the brain should instinctively recognises as a turn signal. The KISS principle applies even to vehicle turn signals...

See my website...

Patent 3,544,962 Sequential Light Flasher (Turn Signals)

AND they're not illegal... it's only illegal to flash red and blue in combination.

...Jim Thompson

...Jim Thompson Hi Jim,

Nice use of SCR's (solid state) back when they first appeared on the scene in the mid 60's. I remember a GE application note from 67 which contained a SCR ring counter which would have done something similar although not so sophisticated as your design.

Sequential turn signals may not be illegal in the US but I remain to be convinced as to whether this is true in other countries. For example Australian Design Rule 6 governing turn indicator lamps says;

QUOTE Operation and visibility of direction indicator lights

A direction indicator light must - a) when operating, display regular flashes of light at a rate of not less than 60, and not more than 120, flashes per minute, b) be controlled by a switch that can be operated by a person in the driving position of the vehicle, c) be wired to an audible or visible tell-tale in the vehicle that shows the driver of the vehicle that the light is operating, d) flash in phase with any other light of the same type fitted on the same side of the vehicle.

The direction indicator light must - a) if the light shows to the front of the vehicle, be - white or yellow if the vehicle was built prior to January 1973 (ADR6), and yellow or amber if the vehicle was built on or after January 1973. b) if the light shows to the rear of the vehicle, be - i) yellow or amber, or ii) if the vehicle was manufactured before 1 January 1973 - yellow or red. c) if the light shows to the side of the vehicle, be yellow or amber.

When operating, a direction indicator light must be visible at all times from a distance of 30 metres from the light. UNQUOTE

Point (d) would implies that if a sequential turn signal was being used on the rear of a vehicle, then the same sequence must be maintained on the front turn signals. I have never seen a sequential turn signal on the front of a vehicle and I submit that such a system would be disallowed on rear turn signals in Australia because it doesn't comply with this design rule.

Ross Herbert

taillights.

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Another sticky point when using these sorts of things is that once *any* of the lights in the assembly is blown, your vehicle is unroadworthy (or equivalent), Australia and New Zealand at least. Makes it very hard to keep it going, although in theory at least LED's should make it easier.

Ken

IIRC, some of Ford's Thunderbirds and Shelby Mustangs had them. Early designs had motor drives with rotaty switches or relay timing arrangements that were notoriously unreliable, which may have been a contributing factor, but they really just never caught on, and most of today's vehicles don't have the lenses or bulbs to accomodate such a thing.

Take at the back end of some trucks. Animated arrows for turn signals, animated circular patterns for 4-way flasher mode. All using LEDs of course.

Worst abuse of cutsy LED signals: center mount brake light. I've seen a few of these that flicker a couple of times rapidly and then go steady upon brake application. But now they've got one that continues to do an intermittent flicker while the vehicle is stopped (brakes on continuously).

IIRC, the Cougar also had them.

Yes, the city buses are having these flasher types installed. I've seen a couple. That doesn't make them legal for us normal folks, though. Just like it is illegal for the citizens to gamble, but the state runs a lottery.

John

The 1966 Ford Thunderbird had sequentials, the drive mechanism was simply a DC gear motor slowly turning a shaft with four cams and roller switches. The fourth cam/switch was for auto completion of a cycle so it would always stop in the right position for the next turn.

They were expensive, difficult to repair and noisy. You could hear the mechanism very plainly, even though it was in the trunk and wrapped in sound deadening material.

No. "Rule 6: There is NOOOOO...rule 6. Rule 7: No poofters!"

Cheers,

Phil Hobbs

Yep. The original Ford design was a motor driving a cam shaft which drove switches in sequence. It was so noisy that it was wrapped in multiple layers of insulation, taking up trunk space... affectionately called the "football".

My chip-plus-SCR's design fit within the light assembly.

...Jim Thompson

Yep. I owned a '67 Cougar.

...Jim Thompson

Yep. The original Ford design was a motor driving a cam shaft which drove switches in sequence. It was so noisy that it was wrapped in multiple layers of insulation, taking up trunk space... affectionately called the "football".

My chip-plus-SCR's design fit within the light assembly.

...Jim Thompson

Heh. I remember one of the homework assignments in an intro digital design course I took was a "T-Bird tail lights machine". The requirement was, yes, to design a state machine to drive the sequential turn signal displays.

I don't remember how to make a Karnaugh map any more but I do remember a bunch of the odd homework assignments...

Guessing... on both sides. I wonder if there's a way to find out definitively.

For reasons unknown, I feel like braying stupid laughter. Why would anyone want turn signals that get more attention?

Thanks for the advice.

No, not guessing at all. I can't be specific other than for my own country where design rules do appear to make them illegal. Other counties such as the USA might be less restrictive in their vehicle design rules.

Perhaps my wording there was a little inadequate to convey the intended meaning. However, if you take the "attention" part which you are having a laugh at, along with the "They tend to be more of a distraction" part, then the intended meaning should be completely obvious to you.

If a following driver's attention is focussed on the gimmicky light chaser sequence then he is less likely to instinctively interpret the meaning of the signal instantantaneously thus creating a potentially dangerous delay.

While fully realizing that some might consider this discriminatory, might I suggest ADD screening as part of the licensing regimen?

Maybe it's common, but that example is in "Digital Design Principles and Practices" by John Wakerly. Another example in that book is to design a traffic light controller to _minimize_ throughput at an intersection.

Matt Roberds

You can suggest anything you like, if you think it would help your argument, even though it tends to smack of sarcasm imo.....I just tend to agree with the sense behind the vehicle design rule (which applies here) in this instance. You are free to disagree and have your own opinion, but you don't have to use sarcasm to intimate that those who don't agree with you must be suffering from ADD.

The facts are that when it comes to vehicle design standards for lighting and external indicators, the powers that be like to have universality. That's why the flash rate and brightness levels are specified in most design standards for turn signals (and other indicators). If every vehicle owner was allowed to install signals to his own liking the range and combination of indicators would be too much for even the least ADD prone person to comprehend. You also have to remember that not everyone driving on the road is young and possessing the 20/20 vision or mental acuity which you so obviously possess. That's why the KISS principle applies with regard to turn indicators.

A simple non-sequential turn signal flashing at a preset rate, as normally encountered on most vehicles, is more likely to be instaneously interpreted correctly whereas, if a person's attention is drawn towards the flashing sequence itself, the meaning of that signal may be delayed momentarily and any required avoidance or corrective maneuvre may also be delayed. This is simply because it is what the brain normally expects for that type of indicator, since it is "usual" and not something out of the ordinary. When a person sees something which is not usually seen or expected (as in the case of a sequential turn signal) they may tend to think, "gee that's a wizz-bang turn signal", rather than concentrating on what the signal means.

I suppose I must be one of the millions who are marching in tune, otherwise sequential turn signals would be found in European made vehicles or even, if even it is not illegal, on more USA made vehicles. Happily, it seems that even in the USA, such turn signals are not widely encountered it seems, so someone there obviously thinks it is not viable or wise to incorporate them as standard items.