Saturday, 24 November 2012

Two excellent new lights

We've added two new front lights to our selection.

The Union UN-4268 has a very boring name, but it's a great light. 35 lux with a well shaped beam from a curved reflector at under €20 is pretty much unbeatable. But this light also has automatic switching dependent on light level (optional and intended for use with hub dynamos) and a powerful standlight which keeps it running for minutes after you've stopped.

The Basta Sprint headlight remains less expensive, but it's got a lower output than this one and doesn't have the other advanced features.

The second new light is completely different. The Philips Safe Ride Pedelec is a top of the range light which combines the 80 lux output of the same company's internally battery powered light with the smaller size of their excellent 60 lux dynamo light in a product designed specifically for use with pedelecs.

If you have a pedelec with less than impressive lights, there's no better upgrade on the market than this. The "motorcycle performance" comes from two high power LEDs and the best optics available which together reach 60 m without blinding oncoming cyclists or drivers.

Another thing that I like about this light is that the included mount can be used for other applications than pedelecs. In fact, it's perhaps the best possible light now available for mounting externally on velomobiles. Even the included bracket can be turned around to works for this application as you see in the attached photo.

Some DIY is needed to use the Philips Pedelec light. You have to supply both power and switching. However, this is made easy by the incredibly wide range of input voltages on which it operates - anything between 6 and 48 volts DC will do, meaning that almost all bicycle power supplies either for motor assist or for velomobile lighting, whether they're based on NiMH, Lithium or even old-school Lead Acid batteries are suitable without any extra circuitry being required.

Finally, this is of course nothing to stop you running this light on a normal bicycle used for commuting or touring. The 80 lux internal battery light from Philips provides much the same performance, but you can achieve longer running times from the pedelec light if you provide a larger battery.

You can find both lights directly by following the links above, or by browsing in our webshop.

7 comments:

  1. Nice looking light. I've been pondering for ages now on getting the battery powered Phillips light.

    I'm not looking for an external mount on the Quest, so now i'm wondering how well it would replace the stock Inoled (with adjustable tilt).

    That it accepts varying input voltage is great. I've got the standard 6v setup in the Quest now, but have been contemplating going to a larger 12v battery.

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  2. Any idea at what voltage the light begins to dim? I.e. if I'm using a 6V battery (5 x NiMH) will it work down to say 5V or below?

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  3. Anonymous: While the box says that 6 V is the minimum, the underside of the light itself actually says 5.5 V. I tried connecting a Philips pedelec light to a 5 V regulated power supply and it lit up very strongly even at this voltage.

    At 5 V it looked like the light was at its full brightness. However, I can't measure light output and it's possible it was a little way short.

    Actually 5 V is a lower voltage than you want to reach with your 6 V battery.

    One volt per cell is about as low a deep discharge voltage as it is safe to reach with a single NiMH cell discharged at a relatively slow rate. However, 5 V for a string of cells is not the same as 1 V per cell because the cells won't be exactly equal. When you reach 5 V for your battery, some cells will likely be considerably below 1 V and this can damage them. For that reason, I would suggest not regularly going below 6 V for the pack, and preferably never below 5.5 V for the pack (an average of 1.1 V per cell).

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  4. Thanks. I guess there is only the full brightness mode? Probably not such an issue on a pedelec but for non-electric bikes a lower power mode would be useful.

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  5. Anonymous: I don't think it will be easy to trick the pedelec light into a low brightness mode because its power supply works to keep constant current through the LED whatever the input voltage. However, there is an alternative which I know does work because I've tried it:

    I installed the 60 lux Philips dynamo headlight in a friend's velomobile with a switch for two different power levels. With this one you can use the simplest circuitry imaginable, just a resistor in series, to give a low power mode. As I recall, I used a 33 ohm resistor (could have been ten ohm but these were the only values I had to hand) and this restricted the current, and therefore battery consumption, to about 1/4 of normal and did much the same to the light output. If you do this, use a 5 W resistor as that will last forever. Smaller wattage resistors may get hot and self-destruct.

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  6. Interesting, I did wonder if that light would work on a DC supply. I know you can use the B&M Cyo this way. B&M said use 7.5V for maximum brightness but no higher than 7.5V.
    Any idea what DC voltage range the Philips dynamo works over? It might rely on the current limiting behaviour of the dynamo so too high a voltage could be bad news.

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  7. All dynamo lights that I'm aware of will work on a DC supply. Certainly all of those which we stock. As all the LED types have bridge rectifiers on their input, you might expect that they wouldn't care too much about the polarity of the connection. However, some B&M lights don't seem to light on DC unless you hook them up "backwards" (i.e. with +ve -> the earth side of the light).

    As for maximum voltages, all dynamos behave as a current source to a large extent and they all generate a very high voltage if no light is connected. As such, all dynamo headlights rely on the current drawn by the light itself to pull the voltage down to something tolerable and all must be designed to be fairly tolerant of slightly higher voltages than normal, as might occur due to the absense of a rear light when used with a 3 W dynamo (this could on its own lead to more than 7 V at the headlight) or because of going down hill at speed.

    I would expect that the Philips light is about the same as the B&M Cyo from this point of view because otherwise they'd experience a high rate of failures.

    However, as I don't have any official figures, any such experimentation would have to be at your own risk.

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