BuckPuck or PowerPuck

[ti-force]

A friend of mine wants my help with installing some type of LED lighting on his lawnmower (Cub Cadet riding mower). My thinking is that 2- XP-G R5's on each side (4-XP-G's total) should be enough for him to see well enough to cut grass, or for whatever reason he needs the additional lighting.

My plan is to use a pair of BuckPucks or a pair of PowerPucks (1 driver for each pair of emitters). I really wanted to use a TaskLED CC5W or another one of his drivers for this project to drive all four emitters with one driver, but the mower has a 12v system, and I'm afraid the input voltage may not be high enough for the driver to run in regulation with 4 emitters wired in series, so I'm hoping either a BuckPuck or PowerPuck for each pair of emitters will work fine.

What do you guys think? Any and all suggestions are welcome.

Here are some concerns I have:

1.) Vibration. I know a lawnmower will have plenty of vibration, so that's probably my biggest concern. Do you think the driver will hold up to the amount of vibration generated by a lawnmower? If not, we may have to mount using a bracket with a rubber pad for the driver to sit on or something like that.

2.) Heat. The engine is front mounted on his mower, which means the headlight housing is built into the front of the engine cowling/hood, so I'm wondering if heat will be an issue for the driver, as well as the emitters.

3.) The datasheet for these drivers states that a 220uf, 50v capacitor should be wired across the input terminals of the driver when the power source is greater than 18" from the driver. I'm not sure where the battery is located on his mower, but if I had to guess, I'd say it's probably under the seat. Either way, it's probably safe to say that it will be more than 18" from the driver. Is this absolutely necessary? If so, are these capacitors usually readily available locally at a chain store? If not, I guess I'll have to order online.

Anyway, what do you guys think about this? Any suggestions? Do you see anything that I'm missing? Do you think this will work?

Also, since you guys are probably wondering about heatsinking and optics for the emitters, his family business has plenty of aluminum bar and rod stock, as well as lathes, milling machines etc...., and he has the machining know-how for making just about anything, so that shouldn't be a problem. Optics will be Carclo or Ledil, and drive current will be 1A.

Thanks.

 

[CDP930]

Im interested to see suggestions as well, thinking of adding additional lighting to my rider as well.

 

[ti-force]

Im interested to see suggestions as well, thinking of adding additional lighting to my rider as well.

Yes, me too. I just hope this isn't in the wrong section. I don't think it is, since my questions are mostly directed towards the drivers, but I did do a lot of rambling about the rest of the project. Hopefully I'm not in the wrong here.

 

[HarryN]

I suspect that the biggest challenge for that application is the same one that that plagues the automotive applications - electrical noise and spikes. George (taskled) has long built his drivers for automotive applications, at least in part because he used them himself for interior automotive lights first.

I have a buckpuck that works fine, I am just not sure of the automotive electrical spiking aspect.

George runs a forum on his web site, and will usually answer well phrased questions posted there in his traditional, short sentence style.

 

[ti-force]

I suspect that the biggest challenge for that application is the same one that that plagues the automotive applications - electrical noise and spikes. George (taskled) has long built his drivers for automotive applications, at least in part because he used them himself for interior automotive lights first.

I have a buckpuck that works fine, I am just not sure of the automotive electrical spiking aspect.

George runs a forum on his web site, and will usually answer well phrased questions posted there in his traditional, short sentence style.

Do you think the capacitor will work to prevent noise and spike problems?

Thanks

 

[Closet_Flashaholic]

Do you think the capacitor a will work to prevent noise and spike problems?

Thanks

Generally, depending on what you are trying to filter, a capacitor alone probably wouldn't give you the protection you are looking for.

Radio Shack used to sell what was called a "generator/alternator noise filter" that was used to filter the 12 VDC for radio equipment. A quick search of radio shack's site didn't show anything.

If you want to suppress voltage spikes generally some type of low-pass filtering either a PI-network or T-network consisting of an inductor and several capacitors (one for low freq stuff(a.c. ripple) and one for the high (i.e. spikes and hash from the brushes/rectifying diodes) frequency stuff would work.

Adding a MOV (Metal Oxide Varistor) to clamp the maximum output is sometimes also added as an additional security. Although once an MOV has been triggered, it must replaced to get the protection again. They are a one-time use device and it's difficult to tell if any single device is "good" or not without some equipment. It's often easier to just replace it, whether it's blown or not.

Any dedicated radio shop (that sells CB/Ham equipment) would probably carry something along these lines. Perhaps even an RV store. Make sure whatever you buy is rated for the total current you expect to draw.

A quick search showed something like:

http://www.tessco.com/products/displayProducts.do?groupId=619&subgroupId=65

(no affiliation with site)

 

[spencer]

Well more light is always better :twothumbs so put 3 XP-G's on each side and that would allow you to use the Hyperboost driver from TaskLED. Or you could put 4 ... or 5 ... or 6.

 

[ti-force]

Well more light is always better :twothumbs so put 3 XP-G's on each side and that would allow you to use the Hyperboost driver from TaskLED. Or you could put 4 ... or 5 ... or 6.

I hear ya , but I'm trying to keep the cost from getting really expensive, and that idea would add an additional $40 (additional driver) + $32 (4 additional star mounted XP-G's) and then the total is somewhere in the neighborhood of $160 and that doesn't even include the filters, capacitors etc...etc....

It's starting to appear as though this whole LED on the lawnmower idea isn't really cost effective. Heck, they build small aircraft for a living, maybe I should suggest some of their aircraft landing lights, although I don't know what voltage they operate on. They're extremely bright on the airplane though. I don't know, I still like the idea of LED's, but if it can't be done a little cheaper, we might have to go the incandescent route.

 

[spencer]

I dissagree. If you go with 3 LEDs per side then thats 6 LEDs at about $8 apiece is $32 plus 1 hyperboost at $40 = $72. Plus a bit for shipping. Nowhere near $160.

 

[ti-force]

I dissagree. If you go with 3 LEDs per side then thats 6 LEDs at about $8 apiece is $32 plus 1 hyperboost at $40 = $72. Plus a bit for shipping. Nowhere near $160.

Ah, I'm with you now. One driver to drive all 6 emitters (of which the total Vf should be 18+ volts), which gives an input voltage lower than Vf (required for boost driver) . Gotcha.. Had sort-of a brain fart a minute ago. I was still thinking I'd need two drivers for some reason.

 

[ti-force]

Generally, depending on what you are trying to filter, a capacitor alone probably wouldn't give you the protection you are looking for.

Radio Shack used to sell what was called a "generator/alternator noise filter" that was used to filter the 12 VDC for radio equipment. A quick search of radio shack's site didn't show anything.

If you want to suppress voltage spikes generally some type of low-pass filtering either a PI-network or T-network consisting of an inductor and several capacitors (one for low freq stuff(a.c. ripple) and one for the high (i.e. spikes and hash from the brushes/rectifying diodes) frequency stuff would work.

Adding a MOV (Metal Oxide Varistor) to clamp the maximum output is sometimes also added as an additional security. Although once an MOV has been triggered, it must replaced to get the protection again. They are a one-time use device and it's difficult to tell if any single device is "good" or not without some equipment. It's often easier to just replace it, whether it's blown or not.

Any dedicated radio shop (that sells CB/Ham equipment) would probably carry something along these lines. Perhaps even an RV store. Make sure whatever you buy is rated for the total current you expect to draw.

A quick search showed something like:

http://www.tessco.com/products/displayProducts.do?groupId=619&subgroupId=65

(no affiliation with site)

Thanks for the info :thumbsup:. I wonder if they use some of these components in their aircraft. The planes have all sorts of electronic gauges and such. If so, that would be sweet .

 

[Closet_Flashaholic]

Thanks for the info :thumbsup:. I wonder if they use some of these components in their aircraft. The planes have all sorts of electronic gauges and such. If so, that would be sweet .

I don't know much about aircraft, however, most equipment, that I am aware of, has self-contained filtering, just as the LED system you are thinking about would need.

Aircraft landing lights are still incandescent AFAIK so they probably don't have/need filtering.

According to this doc: http://www.falconups.com/Optimizing_Aircraft_Power.pdf

Aircraft DC mains are 28VDC, but I suspect YMMV. It probably depends on the specific aircraft.

About 10 years ago:

For myself, I just went the Farm Store and picked up 2 self-contained (12v) Xenon lights for about $25, mounted them to the top of my tractor's rollbar, disconnected the lower lights (useless - way too low to the ground) and reconnected to my new lights. I can mow the lawn all through the night now (I would probably get shot by one of my neighbors though, if I tried to at 3:00AM). I mainly did this for snowplowing (at night), not mowing the lawn.