Direct drive...?

[Robocop]

After a lot of searching here I think I have learned a little on the way quality lights work.I am curious about direct drive.If I understand correct this is simply attatching a power source direct to the bulb.Can someone explain the advantages and disadvantages of this.Also the other methods of lighting such as a booster circuit or regulation.Is this necessary to have in a high quality light?I am looking for a new duty light and would prefer an LED but if I can find a regulated rechargeable(if there is one)I may consider that.It seems that most better lights are not direct driven and I was just wondering why this method is not popular?Thanks for helping a curious mind.

 

[IlluminatingBikr]

Direct drive is the simplest and easiest way to drive a light. Simply connect the power source with your light source, and you have a "direct drive" circuit.

There are a few advantages and disadvantages to doing this. The good things are: quick, simple, and bright! The negative side effects of doing this are: short runtime, curved output (not constant brightness for X hours), and you can decrease the life of your LED significantly. Also direct driving can create lots of heat.

A booster circuit is used when you need more voltage or current than given. Example: Arc AAA.... uses a 1.5 volt battery, but the LED needs about 3.5 volts.

A regulated circuit is my favorite type of circuit for flashlights. You get a nice constant output for a decent amount of time. I would much rather have an output of 20 lumens for an hour, rather than having something direct drive and maybe having 30 lumens for a short while, then significantly decreasing after that.

Another simple, yet effective type of circuit is a circuit using a resistor. The type of output is similar to a regulated output, but not quite as nice. The resistor limits the amount of electricity going to the LED, so the output is fairly flat.

I think the main reason regulated lights are popular is their overall effect. Something direct driven is very bright initially, but doesn't last. Something that is regulated is usually decently bright, for a good amount of time. Also with a regulated light you know how bright it is going to be ahead of time, and can usually calculate a pretty accurate runtime.

Go regulation! /ubbthreads/images/graemlins/buttrock.gif

 

[Robocop]

I am beginning to like the idea of this regulation and I thank you for the explanation.It seems that this regulated idea would be perfect for patrol work as I am sometimes left with a slowly dimming light that is sometimes unpredictable.Does anyone know of a high power rechargeable that is regulated?

 

[brightnorm]

Robocop,

Welcome to CPF!

I know of no high power regulated rechargeable light. The Magcharger, though not regulated will give you a longer bright runtime using Powerstream 2.5mah batteries than with the conventional Mag battery stick.

The Tigerlight is a highly regarded rechargeable.

TIGERLIGHT

It is a surprisingly compact, extremely bright, massive-beamed non-regulated rechargeable that runs for about an hour and comes in two versions, one of them with built-in OC spray. I haven't tested its runtime/brightness performance though you can probably find it in CPF.


Pila lights are highly regarded by some of our LEO’s.

PILA LIGHTS

They are relatively new lights that use rechargeable lithium ion batteries which have very high energy storage capacity. Some of these lights can also be used with 123 primary lithium batteries (non-rechargeable). The Pila batteries can be used in some Surefire lights but must be recharged in proprietary Pila chargers. Search on Pila for more information. I think Madecover was our first LEO to use Pila lights.

If you are interested in a small relatively bright regulated incandescent as a secondary or backup light the Surefire A2 would be a good choice.


SUREFIRE A2


It is a combination incandescent/LED light that is well regarded here. It is a little longer and slimmer than a Surefire 6P and has a regulated incandescent runtime of about 50 minutes. It is slightly dimmer than a 6P and has three small LEDs built into the reflector providing light that is relatively dim but adequate for finding your way in the dark or reading a map and instruments. It has a unique 2 stage tail switch which initially activates the LEDs and then the incandescent as you push harder.

If I may make a suggestion; if you changed the thread title to something like "Cop looking for regulated rechargeable", or "Officer looking for....." etc, you'd probably get more responses.

Good luck on your search .

Brightnorm

 

[Robocop]

Brightnorm thanks for the links and I am still learning the forum procedures.I love the information here and the people as they are quick to help.I put my first thread in the wrong forum and it got moved so my first lesson is message classification..hehe.Thanks for the advice and I have much to learn here.Actually I have never seen the Pila but I do like the idea of a rechargeable light that will also take 3 123 lithiums.I have a friend at work who has a tigerlight with the mace attatched.He has used it on duty for about 7 months.The light is extremely bright and rather sturdy however he has had a few bulb problems.Not enough problems to make me not want one as it is a great light.I think I just wanted something new(dont we all)and was looking for opinions.I do love a high power LED with that bright white glow but I think I may consider this Pila...Thank you Brightnorm again for the link.

 

[brightnorm]

RC,

There are some high power LED lights but they are usually modded lights. Some of our very gifted members take stock lights and MODify them to have new abilities, or convert incandescents to LEDs, but I don't know of any very high power modded LED lights that are regulated.

The two brightest stock LED lights that I can think of off hand are the non-regulated Streamlight TL-3LED and the regulated Surefire L4. The Surefire has a greater total output (lumens) than the Streamlight but it is a very broad non projecting beam, while the narrower and focusable Streamlight beam projects further but nowhere near as far as a powerful incandescent. The McModule is a Pelican M6 modified with a custom mounted 5w LED (McGizmo/Mr Bulk)using a regulation circuit. It's a terrific light and projects better than the L4, but nowhere near its original incandescent host.

There are some very powerful, long throwing unregulated modded LED lights. The SpaceNeedle II is one of the most prominent and will put many incandescents to shame. It is modded into a conventional 2C Maglite and is very rare and hard to get from its creator, Mr. Bulk who is a Hawaiian LEO. It is direct drive and dims fairly quickly.

Good luck with Pila. Please let us know what you come up with and how it performs.

Again, you might want to change the thread title if you want more responses.

Brightnorm

 

[CM]

[ QUOTE ]
IlluminatingBikr said:
Another simple, yet effective type of circuit is a circuit using a resistor. The type of output is similar to a regulated output, but not quite as nice. The resistor limits the amount of electricity going to the LED, so the output is fairly flat.

[/ QUOTE ]

Minor correction, resistive circuits do not have flat output. It merely dumps unwanted voltage into the resistor so the LED gets less voltage. The light output will also drop with the battery voltage as in direct drive. It can also be very inefficient since you're *always* wasting power in the resistor. It is an easy way to reconcile large differences between the battery voltage and what you want the LED voltage to be. Direct drive is the most efficient way to drive but use it only if you know how much you are willing to overdrive the LED when the batteries are fresh.

CM

 

[MR Bulk]

"Direct drive is the most efficient way to drive but use it only if you know how much you are willing to overdrive the LED when the batteries are fresh.

CM"

Hey! Muh hero!

Actually for the way (most) LEO's use flashlights, direct drive is not a bad way to go. Even when the light starts to dim, turn it off a while and turn it back on and it goes back up significantly in brightness, at least for a short while, giving you plenty of warning to get to fresh batteries (or fresh rechargeable 150S PILAs, which I am going to do some testing on with my Space Needle II once I get the rigs all set up).

MR DirectDrive, or more commonly known as

 

[chamenos]

mr bulk: just curious but what's the approximate runtime of your space needle (both I and II)? /ubbthreads/images/graemlins/smile.gif

 

[Robocop]

MrBulk man I got to say that you make some incredible stuff.I wish I had the patience and skill but sad to say I never will.I like the direct drive just because it is simple to understand.I use an Inova X5 for minor stuff like vehicle searches but have no idea if it is regulated.I like the soft white light and do not waste my main light charge on small tasks.I like the commander for larger searches or approaching a car at night.I really like the pelican pm6 or my friends KL4.But the cost factor goes to Pelican however I like the LED and I am learning that you get what you pay for as far as lights go.Thanks for the suggestions MrBulk and maybe soon I can purchase one of your lights and just forget all the other details.Great light for duty very bright.

 

[Chop]

If you want the absolute brightest, Direct Drive is a good way to go. They are easy to build, unless you take it to the next level like Mr. Bulk does.

Of the lights that I have, my 3D M@g mod is the absolute brightest 1W I have and it has the greatest throw. It is big, but it's great for times when you KNOW that you will need a light. How long will it run really bright on a set of batts. I don't know. I've used it as necessary for the last couple of months and it's still brighter than any of my regulated lights, although alot bigger.

The big advantage to this light is that it runs on very common batteries that can be had cheaply.

If you want the absolute brightest, get your hands on one of Mr. Bulk's creations. I don't have one, but I have modded a few M@gs myself and I think that I'd be safe in saying that Mr. Bulk does a better job than I with these direct drive lights.