Regulated incandescents

Can incandescents be made to be regulated? I guess I'm wondering why no one does. Is it because too much power is required, or that the output would be too dim? Just trying to understand. Current regulation is one of my favorite light features and is usually one of my criteria for purchase.

Ahh.. Check out SureFire's A2...
Regulated Incandescent...

Willie Hunt sells regulators for incandescents. I have one of his 2D to 8AA converters. IIRC it uses pulse-width modulation to maintain constant brightness. He sells regulators for headlamps like the Petzl Zoom. See LINK or try a Google search.

www.lightingpro.org also sells headlamps with Willie Hunt's regulator.

Black Diamond's incandescent headlamps are also regulated. See LINK or Google the terms "black diamond" "headlamp" and "regulated".

Usually, incandescent are not regulated because an incandescent bulb, if dimmed, becomes yellowish and the overall bulb efficiency, that is already low, gets even lower.
From the other end, you can power an incandescent lamp with a regulated power converter, so the luminosity stays constant while the batteries discharges. This is not very effective with rechargeables, since this kind of battery has a very sharp voltage falloff at end of charge.
In addition, the efficiency of a regulator is always lower than 70%, it means that the 30% of battery power is lost.
The Surefire A2 regulator is designed so that the bulb, that runs at overall reduced power (but not color temperature), keeps it constant over the entire discharge curve of the batteries.
Anthony

Not quite.

If you use a proper regulator designed for incandescent lamps, such as the LVR units mentioned above, then you can maintain the exact right voltage that the lamp needs for _full_ power operation.

In addition, regulators for incandescent lamps can be extremely efficient, because you don't need all of the filtering components found in a DC voltage output regulator. The lamp will happily use a low frequency square wave supply of the appropriate RMS voltage. This means that a very simple regulator consuming a couple of mA from the supply, with a switch resistance of 0.01 ohm can control many amps to a lamp. The efficiency can easily be > 95%, and >99% is claimed for the LVR.

-Jon

Thanks Jonathan. That's the first time I heard that.

The Lupine bicycle lights are also fully regulated, independent of the lamp type (incandescents, LED or HID. The incandescents have therefore a constant brightness and color for the whole runtime.

This approach is only for "step down" power regulators, where you can use a straight "PWM" (pulse width modulation) to drive the incandescent lamp. Best design rules are that Vsupply has to be at least the double of the lamp voltage. It is true that efficiency is higher, because you have no flyback diode, of coils with high dispersions. I may believe to 95% efficiency with a state of the art design, with MOSFET and tick connecting wires, but not to 99%.

Anthony