Automotive 3/6/9A driver - feeler thread

[DIWdiver]

Also looking at the input voltage and max output current what LEDs and in what quantity do you feel would best be driven? 4 XM-Ls could be driven based on the max output current, but the voltage required is very close to the Vin max. Obviously a car battery wouldn't be able to do this, so it's likely 3 XM-Ls would be the best, though driven at 4.5A each which is a bit much. Is this where the on board pot comes in handy? Set your max output current, and then control the dimming with an external pot?

Four XM-Ls at 3.35V is 13.4V. Add the dropout voltage of the driver (0.2V) and you get 13.6V. This is just below the 'typical' voltage in an automobile that has the engine running. So in a 'typical' system, the LEDs would be driven to max current when the engine is running, and would run at lower current when the engine was off. This configuration puts very low stress on the driver.

Three XM-Ls is 10.05V. Add 0.2 for the driver and you still can run at full output power when the engine is off, and until the battery is pretty dead. This configuration puts lots more stress on the driver.

Three SST-x0 in series is something like 11.4V, so it would probably run on full until the battery is somewhat discharged.

Any of these configurations would be the 'preferred' choice, even though they aren't all 'optimum'.

[DIWdiver]

OK, so let me get this straight(er) - you have a driver with a maximum output pre-set, and then you can switch between high and low (high being the max output and low being a predefined fraction of that maximum).

Adding a potentiometer allows you to adjust the output of either. So if you're in high mode (say 13A) you can adjust it to 50% (6.5A). I'm assuming this can be done while running giving you a 'dimming' effect? Say your low mode in this example is 5A - if you adjusted your high mode by 50% and then switched to low mode, the low mode would be 2.5A as soon as you switch. The same changes work in reverse as well.

So all if this is controlled by an external switch? I assume it would cycle? So for each press you get on-high-low-off? Then a pot to dim the driver?

Sorry if this is all very basic stuff. I'm one of these 'visual aids' sort of people lol.

Yes, although you might have a hard time finding a pushbutton switch that would do high/low/off. Three-position toggle switches are much more common.

[Mattaus]

Sweet as....all understood now. I look forward to seeing these running (and prices of course)

[DIWdiver]

Proto boards have been ordered. They should arrive in 2-3 weeks.

[mvyrmnd]

These are sounding properly exciting.

Would these work with 8 XM-L, 4S2P, on a 6A setting, for 3A per emitter?

It would make one hell of a light bar

[DIWdiver]

Yes. And yes, it would.

But, when you shut the engine off the battery voltage drops, and you will no longer have enough to drive the LEDs to full brightness.

You'll probably never run into the guy building a bar with 15 SST-90s. He's in Sweden, IIRC

[DIWdiver]

I've priced everything out, and if the design doesn't need significant changes, I should be able to hold the price at $30 USD. And that would include a hardware kit with two mounting screws with locking washers, two thermal pads, and one standoff.

The FET gets sandwiched between the board and the heatsink, with one screw through board and FET into the heatsink. The standoff goes under the other mounting hole, to make up the gap between the board and the heatsink.

Mounting screws are either 6-32 x 1/2" TORX head or M3 x 12 Hex socket head, customer choice.
One thermal pad goes between board and transistor to provide good contact of the thermistor to the FET, the other obviously goes between the FET and the heatsink.

[Mattaus]

The price is excellent...and the configuration possibilities make these very tempting. When I get around to building my light bar for my car I'll definitely be using this driver. However I am in the process of re-building my Portable flood lights that I built when I first got into LED lighting. Naturally the build is dodgy, the components are cheap and nasty and I can now most certainly do a better job of them.

My question is however (and I guess this comes down to efficiency which I can't seem to find mentioned yet) would I be best using this driver for a 3s XM-L light (at 4A) or something from TaskLED? This driver is clearly geared towards the automotive user, but I wonder how applicable they'd be elsewhere? I can't see any reason not to use this driver? For the record I plan to use LiPo packs for my flood light power supply - not a car battery.

Sorry if I'm clogging your thread up!

[DIWdiver]

Efficiency isn't exactly a strong suit for this type of driver. Efficiency is power out divided by power in. Power is current times voltage. Since this is a linear driver, the input current and output current are the same, and thus:
Eff = Pout/Pin = Vout*Iout / Vin*Iin = Vout/Vin.

So to make the driver efficient, you have to have the output voltage near the input voltage. Otherwise the driver just dissipates the excess as heat.

Switching drivers, like those from Taskled, Der Wichtel, and others, use various voltage conversion techniques, which result in the output current being different from the input current, and they can achieve high efficiency even when the input voltage is substantially different from the output voltage. Some switchers can even have output voltage higher than the input, which a linear driver can't do.

Unfortunately, switchers are more complicated and more difficult to properly protect from the nastiness of the automotive environment. I've seen threads describing how to do it, and the results are fairly effective, but they are cumbersome and won't protect from the worst case scenarios. It could be argued that most vehicles will never see a 24V jumpstart or a load dump surge, and that is isn't necessary to protect from these, and it's a valid argument. The IS1011 is very well protected, and everything is in one tidy little package. It's just one more choice in the sea of possibilities.

Let's take a peek at some efficiency numbers. I haven't looked up the efficiencies of the Der Wichtel switchers lately, but IIRC they are in the 85-90% range for most conditions, getting as high as 92% in ideal conditions. Taskled drivers run 89-96% for 3S SST-50.

I'll assume the following: XM-L voltage=3.35V, SST-xx voltage=3.7V, Vehicle voltage=13.8V running, 12-12.8V not running

For the IS1011, or any linear driver:
4S XM-L, vehicle running: Vin=13.8V, Vout=13.4, efficiency = 97% WOW!
4S XM-L, vehicle not running: Vin=12.8, Vout=12.6, efficiency = 98% Yee Haa! (but LEDS are not at full power)
4S XM-L, vehicle not running: Vin=12.0, Vout=11.8, efficiency = 98% yeah, yeah

3S XM-L, running: Vin=13.8, Vout=10.05, efficiency = 73%
3S XM-L, not running: Vin=12.8, Vout=10.05, efficiency = 79%
3S XM-L, not running: Vin=12.0, Vout=10.05, efficiency = 84%

3S SST-90 (or -50), running: 13.8V, 11.1V, eff=80%
not running: 12.8V, 11.1V, eff=87%
not running: 12.0V, 11.1V, eff=93%

For the 4S XM-L configuration, the Taskled and DerWichtel drivers wouldn't be able to drive to full power even with the vehicle running. They would do great with the 3S configurations, though they might not drive the luminus devices to full power at 12V input. You also have the option of running 2S LEDs, though at slightly lower efficiency. That would push a linear regulator to 60% efficiency or less, generating unmanagable amounts of heat at higher currents.

As far as clogging up the thread, these are great questions which I'm sure others are interested in too, so keep asking whatever comes up.

[Mattaus]

So despite the linear driver, if you can closely match your Vin and Vout, you can still achieve a pretty efficient system. I plan to go for a 4S XM-L system with a 4S LiPo pack. Vin is 14.4V and Vout is 13.4V which still gives me an efficiency figure of 93%. Pretty damn good IMO. Seen as I primarily use this light for camping the ability to plug it into my car via the 12V socket is very handy as well though with a different efficiency value of course.

Another question for you - still driver related but more application specific. I have a converted 2 head halogen work light (now running 3S XM-Ls in each head powered by some cheap DX drivers). I want to use your driver to power the new system (4S XM-Ls in each head) and am trying to decide if I need 2 (one for each head) or can get away with one. Here's my thinking:

One driver with low set to 4A and high set to 8A. I need the switch that controls on/high/low/off to be connected in such a way that when the driver is set to low only 1 head is powered, and when the driver is set to high both lights are powered. Dimming is then provided by an external pot connected as you have previously discussed.

I guess this connection boils down to whether I can electronically disconnect one of the heads via the same switch that is used to switch between modes. Does this make sense and is it possible? I obviously need to avoid accidently smashing 4S XM-Ls with 8A…I guess a connection diagram would help. I might have to look at some double pole, 3-throw switches. Is that the right term lol?

Yes this system would be cheaper than 2 drivers, but it's also simpler to build, requires less cooling and only needs one switch and pot.

No matter what count me in for at least one driver for now, likely two.

EDIT: Was reading back through the thread and remembered this:

It is important to connect the LED(s) to the driver only when the driver is not powered. This includes momentary interruptions, as with poor connections. It is recommended to solder all connections between the driver and the LED before the driver is powered.
Please note: due to time lag between junction temp and thermistor temp, thermal protection will NOT protect against large overloads like shorted LED, missing heatsink, etc.

Does that kill my idea? Seems like it...

[Bigtoy302]

I will be in for a few to try out. I am designing some off-road light bars now for my rockcrawler buggy. I have a H3CC from Task right now I was going to use with 3 XM-L's. He says it is designed for automotive use and is set at 2.8A. It is not on his site.

I have 26.5mm Carclo optics now and have a order in for the DX 35mm aluminum orange peel reflectors. I am going to try both out. Housings will be billet, made in house. I have my own CNC Machines. I will post pics when I start on them.

I think your driver and 8-12 XM-L's would make a killer light bar.

[DIWdiver]

Mattaus -

The 4S LiPo pack you have has a 'nominal' voltage of 14.4V. But in actuality the voltage changes a lot during discharge. Fully charged it's probably 16.4-16.8V (4.1-4.2V per cell), and most people call 'discharged' somewhere between 3.4V and 2.7V per cell, or 10.8-13.6V. The higher the start voltage (determined by your charger) and the lower the end voltage (determined by the protection circuits, the device, or the user), the more 'capacity' you will get from your pack, but the faster you will wear it out.

Say you have a 1S pack rated at 4000 mA-H, and that it delivers exactly the rated capacity. That may assume 4.15V fully charged, and 2.7V discharged. If you were to charge this pack to 4.2V and discharge to 2.7V, you might get 4200 or even 4400 mA-H. But if you were to charge it to 4.1V and discharge to 3.4V, you may get more like 3200-3600 mA-H.

In your light, where you have 4S XM-L load, it wants 3.35*4 = 13.4V. If the voltage drops below this, the current will begin to drop, and output will reduce. So your pack would work, but you will get less than the full output before the light output begins to fall. This may not be bad, and may even be good, as it gives you some warning that your light is going out.

[Mattaus]

This may not be bad, and may even be good, as it gives you some warning that your light is going out.

Agreed. As long as the circuit protection kicks in too prevent damage, a dimming light is not too much of an issue. Plus I will probably parallel packs to increase my capacity anyway.

[DIWdiver]

OK, so let me get this straight(er) - you have a driver with a maximum output pre-set, and then you can switch between high and low (high being the max output and low being a predefined fraction of that maximum).

Adding a potentiometer allows you to adjust the output of either. So if you're in high mode (say 13A) you can adjust it to 50% (6.5A). I'm assuming this can be done while running giving you a 'dimming' effect? Say your low mode in this example is 5A - if you adjusted your high mode by 50% and then switched to low mode, the low mode would be 2.5A as soon as you switch. The same changes work in reverse as well.

So all if this is controlled by an external switch? I assume it would cycle? So for each press you get on-high-low-off? Then a pot to dim the driver?

Sorry if this is all very basic stuff. I'm one of these 'visual aids' sort of people lol.

Sorry, I guess I lost track of the fact there was an open question on the thread. My apologies for not responding sooner.

Yes, Low is a predetermined (hardware) fraction of High.

Yes, the potentiometer can be changed while running for a dimming effect. If the on-board pot is used, it would be impractical to use as a dimmer in a finished project, but could be used to set the desired output.

If wired correctly, either the on-board or external pot or both can be used to control both modes, as you suggest.

You'd have to have a special switch to get high-low-off with multiple presses. I think there are some around, but they are very uncommon and probably large and expensive. If you really want to use a pushbutton, you'll have to look around and see what's available.

The board was designed with a toggle switch in mind. Think of a standard light switch you might see in your house, but with a center position instead of only up and down. Or the toggle switches used in many canister lights. These are pretty comonly available with three positions, typically called "on-off-on action". Miniature and sub-miniature versions are also available and would be suitable. The way most of these switches are wired, you'd have the center position off, and one side high, the other side low.

This is because of the way the electronics are designed, you have three pins, H, L, C. Connect H to C for high, connect L to C for low, connect nothing to C for off.

For use with an external pot there's a fourth pin, G. Connect the pot endpoints to C and G, then connect the tap of the pot to H or L for high or low mode.

[DIWdiver]

So I have the first prototype built and tested. It has a few PCB layout problems that will prevent it from being sold, but at least it can be fixed and tested.

I ran it at various input and output settings, it looks pretty good. The thermal cutout kicks in and starts reducing the output when the driver is dissipating about 40W into a heatsink that isn't warming up much (around 30C). That means it should be able to handle 10A into a load of 10V or higher while the vehicle is running. There's an external thermistor input with idendical characteristics to the internal temp sensor, which happens (not by accident) to be the same sensor that's on the CSM modules from Luminus. So you can protect both the LED and the driver.

At input voltage above 14.8V it shuts off, and turns back on when the voltage falls below 14.6V (target was 15V and 14.8V, so not bad). I put 60V on it for a while, it didn't seem to mind, and when the voltage dropped below 14.6, it turned back on.

I'll be sending the prototype out for a field test shortly. I'll post any interesting results.

If anyone else desperately wants to try out a prototype, PM me and we'll see if something can be worked out.

I'll be ordering new boards shortly, and pending the field test results, should be offering units for sale soon.

D

[DIWdiver]

It's been called to my attention that there's very little you can do DIY to the external lighting system of a vehicle without running afoul of the law. It doesn't seem to matter much were you are in the world, vehicle lighting is regulated. If your lights aren't certified/approved, they are illegal, even if they meet the appropriate requirements. If they don't meet the requirements, they will not only be illegal, but may endanger other drivers on the roadways.

Fortunately, as far as I know, these laws only apply to vehicles operated on public roads, and dangers to other drivers are greatly reduced if not on public roads.

So when the sales thread opens for this driver, I will adopt a strict policy of OFFROAD ONLY. If I even SUSPECT that you intend to use DIY lights on public roads, even occasionally, or for testing purposes only, I will decline to sell you drivers, whether the suspicion was from one of my threads or elsewhere. If you intend to build headlights, foglights, turn signals, brakelights, marker lights, accent lights or any other external lights for road use, please go somewhere else. I don't want to help endanger other drivers, promote illegal activity, or run afoul of forum rules.

D

[Mattaus]

It's been called to my attention that there's very little you can do DIY to the external lighting system of a vehicle without running afoul of the law. It doesn't seem to matter much were you are in the world, vehicle lighting is regulated. If your lights aren't certified/approved, they are illegal, even if they meet the appropriate requirements. If they don't meet the requirements, they will not only be illegal, but may endanger other drivers on the roadways.

Fortunately, as far as I know, these laws only apply to vehicles operated on public roads, and dangers to other drivers are greatly reduced if not on public roads.

So when the sales thread opens for this driver, I will adopt a strict policy of OFFROAD ONLY. If I even SUSPECT that you intend to use DIY lights on public roads, even occasionally, or for testing purposes only, I will decline to sell you drivers, whether the suspicion was from one of my threads or elsewhere. If you intend to build headlights, foglights, turn signals, brakelights, marker lights, accent lights or any other external lights for road use, please go somewhere else. I don't want to help endanger other drivers, promote illegal activity, or run afoul of forum rules.

D

I can safely say that here in Australia this sort of driver will be used purely for off-road lighting applications. At least that's what I intend on using it for

I would love to test these drivers - I happen to have two 3-series connected XM-L flood lights (not automotive, though they are run off a 12V Deep cycle battery) that are in need of new drivers. I was going to put in some cheap DX drivers I had lying around due to an up coming camping trip (to the snow in a months time) but if I can get my hands on 2 relatively soon I'd be happy to purchase and test them. I doubt they'd be available in time though so not too much to worry about! Was a price mentioned? I need to sleep so I'll read back through the thread in the morning...

Thanks!

- Matt

[DIWdiver]

If there's no charging system, other heavy loads, etc, then the 'automotive' version of the IS1006 would be a good choice too. I've been shipping those for quite a while. It doesn't have thermal protection, overvoltage cutout, and integrated transient suppression, but the basic performance is very similar. I could make you a 3A one (or several) in a week. And that's only because I'd have to order parts for the lower current. They're $26 USD each, plus a one-time $5.00 customization charge since I haven't made that current setting before. Shipping is $13 and change to AUS.

Here's a link to the sales thread:
http://www.candlepowerforums.com/vb/...w-and-Improved!

I haven't set a price on the IS1011 yet, but it looks like it will be $30-35 USD.

[Mattaus]

If there's no charging system, other heavy loads, etc, then the 'automotive' version of the IS1006 would be a good choice too. I've been shipping those for quite a while. It doesn't have thermal protection, overvoltage cutout, and integrated transient suppression, but the basic performance is very similar. I could make you a 3A one (or several) in a week. And that's only because I'd have to order parts for the lower current. They're $26 USD each, plus a one-time $5.00 customization charge since I haven't made that current setting before. Shipping is $13 and change to AUS.

Here's a link to the sales thread:
http://www.candlepowerforums.com/vb/...w-and-Improved!

I haven't set a price on the IS1011 yet, but it looks like it will be $30-35 USD.

I'll have to read through that sales thread but if I can connect those drivers up using the same methodology as detailed in this thread (hi/low modes with dimming in each) then I'll defintely grab two 3A modules

- Matt

[JDadam]

Have you guys done any more testing of these drivers?

[DIWdiver]

I'll save you some reading. Yes, you can do the external dimming pot and switch high/low with either shared or separate pots. The IS1006 is missing the G terminal, but it's the same as the B- terminal, so it's not a big deal. You'll get better behavior if you connect the low side of the pot to B-at the board instead of at the opposite end of a long wire carrying the LED current, but it's not critical.

[e015475]

Is the IS1011 automotive driver available now? Fabbing some XML light bars and this seems the best power supply I've identified. Please advise. Is there a sales thread?

My application is strictly offroad for a non-licenced tube chassis sand car used only in the Imperial Sand Dunes

Please advise,

Phil

[DIWdiver]

I'm just about to order a small batch of production boards. They should be available in a few weeks. There isn't a sales thread yet, but should be sometime next week.

[e015475]

You'd stated in a previous posting in this string-

"With all that in consideration, I'm seriously considering offering only the 13.5A adjustable version, with 4:1 high/low. Anything else would be custom. Currently the customizaion fee would be $5.00 per order."

From a light output standpoint, I'd like to string 5 XM-L LEDs per driver driven at 2000ma and two drivers per lamp. The 13.5A design would allow me to push it a little more, especially if I could dim the lights to suit conditions.

Please clarify which design is in production, and if it isn't the 13.5A version, the leadtime to produce about 6 units (assuming of course you're willing to produce them)

Thanks and regards,

Phil Dooley

[nofearek9]

good news!

[mvyrmnd]

good news!

[DKlaser]

Glad to hear this DIW! As you know I already own a couple of your non automotive drivers that you have helped me set up for an automotive environment (off road of course). I have managed to get one of them setup so far and it works great. I have a thread here in this forum with the details of the build. Really looking forward to this new version.

[DIWdiver]

You'd stated in a previous posting in this string-

"With all that in consideration, I'm seriously considering offering only the 13.5A adjustable version, with 4:1 high/low. Anything else would be custom. Currently the customizaion fee would be $5.00 per order."

From a light output standpoint, I'd like to string 5 XM-L LEDs per driver driven at 2000ma and two drivers per lamp. The 13.5A design would allow me to push it a little more, especially if I could dim the lights to suit conditions.

Please clarify which design is in production, and if it isn't the 13.5A version, the leadtime to produce about 6 units (assuming of course you're willing to produce them)

Thanks and regards,

Phil Dooley

The design is the same no matter what the current level, just built with different resistor values. It takes a few days and a few dollars to get them, so additional lead time is usually only a few days, up to a week. That can be reduced if you want to pay expedited shipping. And yes, I'm willing to do it.

My point was that since it can easily be made to be user-adjustable from 0-13.5A, what's the point of making, say, a 0-10A, or a 0-3A version. I can save about $1.50 by making a fixed version, which would force me to offer 13.5A, 9A, 5A, 3A, custom, etc., in addition to the adjustable. I'm just thinking it's probably not worth it. However, I will consider the desires of the community, as the whole basis for the project was to fill an unsatisfied need in the community.

As far as the configuration you are considering, that's a subject for another post, or perhaps several. I'll get to that shortly.

[DIWdiver]

The new boards are ordered! I should have 20 pcs in 2-3 weeks. Now I have to make a data sheet, sales thread, order the parts, finalize the price (still looks like $30-35), etc. Should be done before the boards get here.

[DKlaser]

How many emitters can the 13.5a version drive @ 3a or a little over for each emitter?