Fast-blinking turn signals

[doc47]

I can't think which forum to stick this in, so here goes:

 

I replaced the turn sigs on my Dakar with some cheapos from Cycle Gear. They look fine, do the job, and are a bit shorter than the OEMs, which makes me think they'll be less likely to break next time the bike goes down.

 

The resistance must be lower, though, they blink at a frenetic rate. I'm told that adding in a resistor in-line will slow things down. Any ideas how much resistance would be necessary?

[Tri750]

Normally, on the hook next to the LED turn signals is the same brand turn signal fixer or medic or resister. Most all bikes that people put those signal on require this. The kid at CG should have suggested it.

[dirtrider]

Morning doc47

 

Connecting a resistor IN-LINE will make your problem worse not better.

 

You want to DECREASE the circuit resistance not increase it.

 

So you need to add resistance ACROSS the circuit not in-line with it. (ie= add more load)

 

 

What usually works (not sure on the Dakar but for most bikes)-- is a 5 or 6 ohm 40 to 50 watt resistor wired between the two wires going to each aftermarket LED turn signal.

 

Those resistors will get hot so mount them in a safe environment (don't just tape them along the wire harness).

 

 

[doc47]

Much thanks. I don't understand how wiring more resistance across the circuit will decrease the resistance....or am I misunderstanding something?

Frankly, I'm convinced electricity is FEMALE! Can't figure it out, and when it does work it's likely to do something unpredictable before long.

Interestingly, the T-sigs are not LED. They have small, cylindrical incandescent bulbs with conical tops. I'm wondering where I'll ever find a replacement if one burns out.

Think the same values (ohms, wattage) would still apply?

[kioolt]

Much thanks. I don't understand how wiring more resistance across the circuit will decrease the resistance....or am I misunderstanding something?

 

Think about it like this.

 

The existing bulb is nothing more then a resistor that lights up when voltage is applied across it. The existing bulb uses x amount of current. When you add a resistor across the bulb (hook up in parallel to the existing bulb) you have not changed the amount of current going through the existing bulb. You have added an additional path for current through the resistor. Let's call this current y. So now you have current x + y as your load on the turn signal circuit. x + y is more current then just x. According to ohm's law, if the current has gone up but the voltage has remained the same, then the resistance has gone down.

[Boffin]

Much thanks. I don't understand how wiring more resistance across the circuit will decrease the resistance....or am I misunderstanding something?

 

Think about it like this.

 

The existing bulb is nothing more then a resistor that lights up when voltage is applied across it. The existing bulb uses x amount of current. When you add a resistor across the bulb (hook up in parallel to the existing bulb) you have not changed the amount of current going through the existing bulb. You have added an additional path for current through the resistor. Let's call this current y. So now you have current x + y as your load on the turn signal circuit. x + y is more current then just x. According to ohm's law, if the current has gone up but the voltage has remained the same, then the resistance has gone down.

 

As an electronic engineer of 40 years standing I think of electrickery as water flowing in a pipe. Make the pipe thinner, you add resistance to flow. Put another pipe alongside the thin pipe and there is less resistance to flow. The total resistance to flow is always less than any pipes you had there before.

 

Andy

[dirtrider]

Morning Doc47

 

Both the explanations above explain the series & parallel resistance but you still need to understand water flow or electrical flow.

 

If that explains it for you then ignore this--

 

If you still don't understand then this MIGHT help by putting another spin on it.

 

A local fair grounds has only one gate open (that is your new T/S light), that gate will allow 3 people through at a time in a steady stream of 3 wide people.

 

They now add another gate just before that gate that only allows 1 person at time through it (they just added series resistance). So now the amount of people initially entering are limited to only one at a time. They still have to travel through the 3 person gate but seeing as the 1 person gate has limited their numbers they only slow down a little as they pass through the 3 person gate. (end result is: 1 person gate IN FRONT OF the 3 person gate equals less people entering per hour)

 

 

A local fair grounds has only one gate open (that is your new T/S light), that gate will allow 3 people through at a time in a steady stream of 3 wide people.

 

They now add another gate BESIDE that 3 person gate. That gate only allows 1 person at time through it (parallel resistance) but these people are IN ADDITION to the people passing through the 3 person gate. So now the amount of people entering are 3 at a time through the 3 person gate + 1 at a time through the 1 person gate.

 

SOME still have to travel through the 3 person gate but seeing as the 1 person gate has been added some ADDITIONAL now enter through that gate . (end result is: 1 person gate BESIDE the 3 person gate equals MORE people entering per hour)

 

People= current flow

 

Gate= resistance to flow

[Sweendog]

Morning Doc47

 

Both the explanations above explain the series & parallel resistance but you still need to understand water flow or electrical flow.

 

If that explains it for you then ignore this--

 

If you still don't understand then this MIGHT help by putting another spin on it.

 

A local fair grounds has only one gate open (that is your new T/S light), that gate will allow 3 people through at a time in a steady stream of 3 wide people.

 

They now add another gate just before that gate that only allows 1 person at time through it (they just added series resistance). So now the amount of people initially entering are limited to only one at a time. They still have to travel through the 3 person gate but seeing as the 1 person gate has limited their numbers they only slow down a little as they pass through the 3 person gate. (end result is: 1 person gate IN FRONT OF the 3 person gate equals less people entering per hour)

 

 

A local fair grounds has only one gate open (that is your new T/S light), that gate will allow 3 people through at a time in a steady stream of 3 wide people.

 

They now add another gate BESIDE that 3 person gate. That gate only allows 1 person at time through it (parallel resistance) but these people are IN ADDITION to the people passing through the 3 person gate. So now the amount of people entering are 3 at a time through the 3 person gate + 1 at a time through the 1 person gate.

 

SOME still have to travel through the 3 person gate but seeing as the 1 person gate has been added some ADDITIONAL now enter through that gate . (end result is: 1 person gate BESIDE the 3 person gate equals MORE people entering per hour)

 

People= current flow

 

Gate= resistance to flow

Most importantly: Who's buying the funnel cakes?

[racer7]

Back in the old days (lates 60s, early 70s) when I made my own turn signal setups, I used to tune their rate and output by trying a few different incandescent bulbs until I got one that did the job. Sometimes I ended up using 6V bulbs on 12V bikes- which works fine in many cases as long as they're only in the signal,

 

Try playing with some up watt bulbs that fit in the socket to see if you get a reasonable flash rate back. Or find a flasher that wants a lower load. Both or a combo are possible fixes.

[doc47]

Thanks, gents! The fluid-flow model does make sense to me...as does the fair-grounds model. Both good analogies.

I'll pick up a couple of different resistors at Radio Shack and fiddle around with 'em.

[doc47]

And I'll have one funnel cake and a cotton candy.