Re: For those who believe in electricity

Am 08.04.2025 um 18:33 schrieb Frank Krygowski:

On 4/7/2025 11:56 AM, sms wrote:

On 4/7/2025 8:16 AM, Zen Cycle wrote:

On 4/6/2025 10:22 PM, Frank Krygowski wrote:

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A battery puts out DC, it does not provide "half of a sine wave."
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An LED dynamo light would be rectifying the AC into DC, though there are ways around this if the light has multiple LEDs (two LEDs each conducting for half the cycle). If there is only a single LED it can still be powered by the AC from the dynamo but it would be wasteful as it would only be lit for half the cycle.

As I mentioned in discussions here years ago, one LED dyno headlight I own has a very simple circuit: IIRC just a bridge rectifier, a voltage regulator, a resistor and a capacitor feeding one LED.
 It's obvious from my photos of this B&M lamp that the electronics are much more complicated. I'm disappointed that the electronics experts here have never commented on what the likely functions of all that complexity.

Not being an electronics guy myself, I can still comment on the "likely function of all that complexity".
<https://www.bike-components.de/de/busch-mueller/Lumotec-IQ2-Eyc-N-Plus-LED-Frontlicht-mit-StVZO-Zulassung-p37751/>
The main parts are identical to a cheap light:
Rectifier, one LED, heat sink, switch.
The main difference to a cheap LED light is the effort taken to optimize the optical system (reflector design and low-tolerance placement of the LED in relation to the reflector) - The "N" in the name stands for "optimized near field".
The "Plus" in the name adds a (gold-cap?) capacitor, probably 1.0F or 2.0F, with two purposes:
a) provide several minutes of "stand light" functionality (IIRC typically switches off after 4 minutes)
c) reduce flicker at low speeds
The additional electronics is necessary to milk more than 3W out of a "nominally 3W" (hub) dynamo; I'm not sure whether this works for your bottle dynamo.
Rolf