StromTrooper banner

1 - 20 of 32 Posts

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #1 (Edited)
I have some LED lights on my forks as running/conspicuity lights (http://www.stromtrooper.com/showthread.php?t=41386). I'm about to switch to flushmount signals in front, and I want to make those always-on running lights also function as turn signals, since the flushmounts are hard to see from the front. So I'm trying to figure out a way to interrupt the steady-on state for each light when the signal on that side is turned on.

I thought of putting a normally-closed relay in line with each light, triggered by the flasher. But that means two little clicky relays in the fairing, which seems less than ideal. There must be a better way to do it, right? Any of you EE types have suggestions? TIA.
 

·
Premium Member
Joined
·
412 Posts
Could you just wire them directly to the turn signal (in parallel)?

Don't have any up front but thats the way my LED turn signals are wired in the rear.
 

·
Premium Member
Joined
·
3,722 Posts
Could you just wire them directly to the turn signal (in parallel)?

Don't have any up front but thats the way my LED turn signals are wired in the rear.
Won't work. When the running lights are on (all the time when the ignition is on) the filament of the lamp has a completed circuit all the time. When the turn signal is on there is nothing to BREAK the circuit of the running light so it won't turn off. Effectively what you have to do is reverse the logic of the turn signal. Rather than making a circuit to turn the lamp on it has to break the circuit to turn the lamp off.

The easiest way is to use a lamp with two filaments, one for the running lights and one for the turn signals. That's typically how brake & tail lights work.
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #4
The easiest way is to use a lamp with two filaments, one for the running lights and one for the turn signals. That's typically how brake & tail lights work.
Yes, but they're LEDs, and not even bulb-type LEDs.
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #5
Bumpity. I know there are members here with more electrical knowledge than me.
 

·
Cowboys aint easy to love
Joined
·
2,113 Posts
Google "motorcycle turn signal relay" and go there -- looks like lots of choices. I'd do it but I have to go to bed now -- joining volunteers searching for flash flood victims tomorrow shortly after dawn.
 

·
Registered
Joined
·
517 Posts
Bumpity. I know there are members here with more electrical knowledge than me.
You could use 'magic blinkers' from:
http://www.customdynamics.com/magic_blinkers.htm

But these will make your running lights blink opposite of your turn signal, i.e. for every on pulse to your turn signal these will result in an off pulse for your running lights. I tried them and found it annoying that they were not blinking in sync. Same general idea as your relays.
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #8 (Edited)
dancer said:
Google "motorcycle turn signal relay" and go there -- looks like lots of choices.
I already have an LED-compatible turn signal relay installed.
I think I'm not making myself clear. The issue is, the running lights need to be on except when the signal is on -- it's backwards from a normal turn signal circuit.

Ideally, each running light would have two hot wires running to it: one steady on, and one shared with the turn signal on that side. Only one of these circuits would be complete at any given time. Normal operation would be the steady power. When the signal is turned on, something (this is what I'm trying to figure out) would switch the running light's power source from the steady hot to the turn signal hot -- an electronically activated A/B switch. Am I making sense? It seems like it would be simple if one just knew what kind of switch/relay/widget to use. :confused:
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #9
You could use 'magic blinkers' from:
http://www.customdynamics.com/magic_blinkers.htm

But these will make your running lights blink opposite of your turn signal, i.e. for every on pulse to your turn signal these will result in an off pulse for your running lights. I tried them and found it annoying that they were not blinking in sync. Same general idea as your relays.
Right. I'd like to avoid that reverse-blinky if possible.
 

·
Registered
Joined
·
517 Posts
There is a way to do it I suppose. When I was working on my bike one day I had the misfortune of breaking the ridiculously over engineered turn signal switch.


I replaced it with a SPDT switch, works like a charm, far more robust and a hell of a lot cheaper to replace.



What you want to do can maybe be done by replacing the turn signal switch with a similar TPDT switch.

Edit: The SPDT switch is of the on-off-on variety, and for both lights I think would need a triple pole double throw switch, I need to figure out how exactly that needs to be wired.....
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #11
OK, I think I have it figured out. I was hoping to keep the factory switch, since I like the push-to-cancel function, but it may not be possible since the flasher is before the switch in the circuit.

So how about this: a DPDT (center off) switch, in conjunction with a pair of SPDT relays, one for each side. One pole of the switch simply replaces the factory switch like you did. The other has a steady (non-flashing) hot wire on the common terminal, and each on position triggers one of the relays. Each relay toggles the power source of its running light between steady and flashing.


(Thanks Arne for your specific thoughts, and everyone else for making me rethink my question. I kinda broke my own "research before posting" rule, but for some reason I just couldn't frame the question correctly until I realized, duh, there are DT relays too.) :bom_dunce:
 

·
Registered
Joined
·
435 Posts
Don't go tearing your stock turn signal switch out yet! There's a way to do this, I just have to think about it for a while.

You seem comfortable wiring relays, how comfortable are you with something a little more complicated? Say, with a few transistors and diodes?
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #13
I'm in the process of expanding my knowledge about circuits by taking on various projects. Working on a water level sensor for a friend's rainwater system now. So bring it on!
 

·
Premium Member
Joined
·
2,231 Posts
Discussion Starter #15
That's smart...always learn on the friend's stuff.
Heh, yeah. And he's paying me with a tumbler-style composting bin and a "needs work" chainsaw!
 

·
Registered
Joined
·
435 Posts
Option #1

This should work:



As long as the turn signal is off, the LED cluster is powered by +12V switched; in other words, always on. When the turn signal is energized, it charges C1 and powers the relay, switching power for the LED cluster from +12V Switched to the turn signal. Between flashes, the relay derives power from C1, keeping the LED cluster connected to turn signal. When turn signal is extinguished, the capacitor discharges through the relay and the relay switches the LED cluster back to +12 Switched. You will need one of these circuits for each side.

The trick is going to be getting the right value for C1. It needs to be large enough to power the relay between flashes. I had two relays on hand that I got from two different air horns I bought. One was a 30 amp that required 250mA to energize. For this one, 3000uF was not enough. The other relay was a 40 amp, and required 80mA to energize. For this one, 3000uF was just about right. You will have to size your capacitor to match your chosen relay and desired time delay.

The advantage to this circuit is it's simplicity. One disadvantage is the physical size of the capacitor. This limits relay selection to ones that draw lower current. Another is that the turn signal circuit is required to power the LED cluster. (I don't know how much current it draws!) If this is a problem, the above circuit can be used to power a relay that powers the LED cluster.

If this doesn't work out, I'm pretty sure I could do it with a 555 timer IC. Let me know what you think...
 

·
Registered
Joined
·
517 Posts
Don't go tearing your stock turn signal switch out yet! There's a way to do this, I just have to think about it for a while.

You seem comfortable wiring relays, how comfortable are you with something a little more complicated? Say, with a few transistors and diodes?
Very curious to see what you come up with.
 

·
Registered
Joined
·
517 Posts
This should work:



As long as the turn signal is off, the LED cluster is powered by +12V switched; in other words, always on. When the turn signal is energized, it charges C1 and powers the relay, switching power for the LED cluster from +12V Switched to the turn signal. Between flashes, the relay derives power from C1, keeping the LED cluster connected to turn signal. When turn signal is extinguished, the capacitor discharges through the relay and the relay switches the LED cluster back to +12 Switched. You will need one of these circuits for each side.

The trick is going to be getting the right value for C1. It needs to be large enough to power the relay between flashes. I had two relays on hand that I got from two different air horns I bought. One was a 30 amp that required 250mA to energize. For this one, 3000uF was not enough. The other relay was a 40 amp, and required 80mA to energize. For this one, 3000uF was just about right. You will have to size your capacitor to match your chosen relay and desired time delay.

The advantage to this circuit is it's simplicity. One disadvantage is the physical size of the capacitor. This limits relay selection to ones that draw lower current. Another is that the turn signal circuit is required to power the LED cluster. (I don't know how much current it draws!) If this is a problem, the above circuit can be used to power a relay that powers the LED cluster.

If this doesn't work out, I'm pretty sure I could do it with a 555 timer IC. Let me know what you think...
The only other drawback here is the fact that electrolytic capacitors have high leakage currents, poor tolerances and poor capacitance versus temperature characteristics. They are generally unreliable and have short life spans. I do a lot of scientific instrument repair and invariably the components that fail are either high power components (power mosfets etc) or capacitors.
 

·
Registered
Joined
·
435 Posts
The only other drawback here is the fact that electrolytic capacitors have high leakage currents, poor tolerances and poor capacitance versus temperature characteristics. They are generally unreliable and have short life spans. I do a lot of scientific instrument repair and invariably the components that fail are either high power components (power mosfets etc) or capacitors.
Come on, you are just nitpicking.

You are technically correct on all accounts, but none of them really matter.

- High leakage current: immaterial in this application.
- poor tolerance: given that a component will have to be selected by hand, also immaterial.
- Poor temperature characteristics: use a high temp version and make it a little larger than necessary.
- Short life span: by whose measure? Short for an electronic component, but I'd bet it'll last ten years! If I had one on my bike and had to replace it after ten years, I would not complain.

I'll admit, this isn't my favorite solution to the problem. But it is simple and has a low parts count. In fact, the circuit might be able to lose R1 & D2. I added them just to be safe.
 

·
Registered
Joined
·
435 Posts
I do a lot of scientific instrument repair and invariably the components that fail are either high power components (power mosfets etc) or capacitors.
I've done my fair share of repair as well. What you say is true and makes it much easier to decide where to start looking on a fresh repair job!
 
1 - 20 of 32 Posts
Top