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[Bartimaeus]

I'm not a fan of the turn signals on motorcycles because of how easy it is to forget that they're on. Sure, you can get into the habit of pressing in to cancel the signal at random times, but that's just something that distracts from the ride. So I made a simple circuit to add vibrational feedback that vibrates with the blinking of the lights on my Zero DS.

The schematic for this is pretty straightforward, the output for both signal lights gets brought in to a voltage regulator to bring the voltage down from 12v to the 3.3v that the vibrator is rated for. The purpose of the diodes is to prevent the signal from one channel looping back to the lights for the other side (otherwise both sides would light up regardless of the way you signaled).


I threw together a proof of concept with parts that were already on hand and had good success with it once I added some capacitors to the inputs and outputs (needed for this particular regulator, not shown in the schematic or the photos).


I was a bit worried that there wouldn't be a ground return line brought out to the switch cluster, but fortunately one is used on the horn switch (gray wire on mine). The location I hot glued the circuit to turned out to not be ideal because it shares that space with the wire bundle, making it difficult to close everything back up without the turn signal lever rubbing on the top half of the cluster.


Here you can see where I attached the vibrator to the sidewall of the case. I think that this is also a better location to stuff the circuit.


Test video with it plugged in to the bike before I mounted it to the handlebar:


While this setup works and is effective while the bike is stopped, it is very hard to notice if the bike is going faster than 5-10mph. I intend to make a small circuit board that people can buy as a kit, and will try out a few different parts for making the vibration, maybe something that takes the resonant frequency of the handlebars into account. I'm also thinking of making a clamp on unit that can go on any bike easily and could have a much bigger motor, but haven't come up with a clean way to splice that into a wiring harness. I also have a feeling that this system will work best on electric bikes since they don't have an engine shaking the entire bike.

[BrianTRice@gmail.com]

That's interesting! I don't have a problem with turn signal awareness but I'm sure others do.

[Fred]

Could you not find a higher voltage vibration motor? Using a regulator to drop the voltage is very inefficient, and using an LDO regulator to drop about 9V is a particularly odd choice.

[Bartimaeus]

Could you not find a higher voltage vibration motor? Using a regulator to drop the voltage is very inefficient, and using an LDO regulator to drop about 9V is a particularly odd choice.

There are some, but none that were that small from what I could see (which makes sense if you consider the biggest use of those is in cell phones and pagers) and I really wanted to see if I could get away with a solution that wouldn't show any signs of modification. And for both of those parts it was a matter of them being free and available. And while it's about 70mA going in on the 12v side I'm not really sweating the 0.84 watts on a 50% duty cycle, and only for relatively brief amounts of time. Even if it used a full watt of power at 100% duty cycle, I've got a nominal capacity of about 8.6kWh in my bike. I may keep using an LDO in the design anyway since electric vehicles already have more than enough electrical noise to go around and there's no need to add more with a switching power supply.

[Fred]

I'd go for a 3 motors in series then. More vibration. No more power being drawn. The diode you're using for the "or" gate will drop a volt or so. The motors will probably be OK a little over their specified voltage (or add another diode in series to drop a little bit more). No need for a regulator at all.

[Bartimaeus]

I'd go for a 3 motors in series then. More vibration. No more power being drawn. The diode you're using for the "or" gate will drop a volt or so. The motors will probably be OK a little over their specified voltage (or add another diode in series to drop a little bit more). No need for a regulator at all.

There are some problems with having three motors that actually can result in little to no improvement in vibration. There's no way to make sure that the rotation of all of the motors are in phase with each other, and if they're perfectly out of phase they can cancel each other out (assuming that the motors are mounted on the same plane). Eccentric Rotating Mass (ERM) motors give vibration in two axis, so even if thee ERM motors were mounted orthogonal to each other there would be coupling between them on each axis.

I also suspect that since they're inductive loads and not resistive the EMI from the motors will prevent normal current flow while they're in series.

[Bartimaeus]

I did up a small PCB that does essentially the same thing as my original protoboard version did, but it should be more compact and will let people make their own without too much effort.

This is the 3d view of it. I chose surface mount components so the bottom would be flat (easier for mounting) and to reduce the overall height. I made sure to choose parts that should be easy to hand solder though.


Here's the schematic for reference:


As you can see, they're super cheap (you have to order in quantities of three from OSH Park)


You can order some yourself here: https://oshpark.com/shared_projects/sA4KNcg9

I've also put together some parts to purchase from Digikey,  ordered a couple different motors to try out. I think that the total parts cost for one setup should be below $10.


I may ask a local fab/assembly shop for a quote on making and assembling some complete boards for people to buy depending on interest. Depending on space constraints I may design an overmold to make the thing waterproof (I fortunately have access to a small 1.5 cubic inch injection molder and a CNC mill to make the mold with).

[BrianTRice@gmail.com]

I got to see/try this in person, and now am interested in it, because he figured out how to get the component cost/count down and to fit it inside the left switch assembly. It's nice work! We need more mods like this.

[Chief_Lee_Visceral]

Cool. I have anxiety when I forget and usually dope slap my helmet by way of apology to other drivers. I will buy a half dozen at least if you make them!