CIRCUITS FOR DYNAMOS & HUB GENERATORS

BICYCLE STANDLIGHT AND FLICKER ELIMINATION UNITS

Standlight Circuit SL-SC is for Nicelite LED bulbs and will deliver flicker-free illumination with a hub generator a few seconds after beginning riding, as the capacitors receive charge. 

Standlight Circuits SL-01 and SL-02 with non regulated bulbs and a hub generator may reduce rather than eliminate flickering. The voltage while riding will pulse between the applied battery voltage and approximately 6V. Nicelite LED bulbs are regulated and they will deliver constant brightness within this fluctuating voltage range.

The output from a tyre driven dynamo is high frequency and will always appear steady at riding speeds without additional smoothing.


 

The SL-SC capacitor standlight circuit is for use with Nicelite LED dynamo bulbs. The areas shaded in green could be fitted inside a light, subject to space available. Just one or all lights can be fitted. Nicelite dynamo bulbs each require 1W and although only two bulbs are shown, three bulbs can operate from a 3W generator or dynamo.

This circuit is in use by a customer who kindly sent the photo. The bicycle has a tyre driven dynamo. Standlight running time is over 45 seconds once the capacitor is fully charged, which requires about 2 minutes of riding.

COMPONENTS SL-SC

L1 & L2 = NL412, NL432, or NL437R
BR = Bridge Rectifier 1A
X1 = Regulator XGEN, XGEN2 or XGEN5
1F = 1 Farad 5.5V Super Capacitor (supercap)

NOTE: Either the generator coil OR the bulb holders must be electrically isolated from the bicycle frame to avoid a short circuit at the bridge rectifiers (BR). Sturmey Archer Dynohubs and probably most modern hub generators are isolated from the bicycle frame.


The SL-01 circuit is based on the Sturmey Archer FSU unit, but miniaturised. It has not been tested and is offered as a suggestion only. We will be very pleased to receive feedback.

COMPONENTS SL-01

BR = Bridge Rectifier 1A
D1 = Diode Rectifier 1A
S1 = Headlamp Switch (if fitted)
S2 = Switch in SL-01 unit
* (optional if S1 is fitted)
B1 = 3 x AA alkaline cells in battery holder
X1 = Regulator XGEN, XGEN2 or XGEN5

* With a Dynohub, S2 will select (a) strobing when moving (Nicelite LED Bulbs), or (b) continuous light whether moving or stationary.

Filament bulbs or Nicelite LED bulbs NL412, NL432, NL437R can be used.

NOTE: Either the generator coil OR the bulb holders must be electrically isolated from the bicycle frame to avoid a short circuit at the bridge rectifiers (BR). Sturmey Archer Dynohubs and probably most modern hub generators are isolated from the bicycle frame.



The SL-02 circuit is based on the Sturmey Archer FSU unit, but miniaturised. It has not been tested and is offered as a suggestion only. We will be very pleased to receive feedback.

COMPONENTS SL-02

BR = Bridge Rectifier 1A
D1 = Diode Rectifier 1A
D2 = Diode Rectifier 1A
S1 = Headlamp Switch (if fitted)
S2 = Switch in SL-02 unit
* (optional if S1 is fitted)
B1 = 3 x AA Nickel Cadmiun Rechargeable Cells
R1 = Charge resistor
F1 = Fuse 1A
X1 = Regulator XGEN, XGEN2 or XGEN5
Bulbs = Nicelite NL412 or NL432, NL437R


* With a Dynohub, S2 will select (a) strobing when moving (Nicelite LED Bulbs), or (b) continuous light whether moving or stationary. Also with a Dynohub S1 probably needs to be open ("off") for battery charging as there may be no surplus power from the 2W Dynohub when two 1W Nicelite bulbs are powered. A charging socket for an external power supply could be included in SL-02.

Two Nicelite LED bulbs NL412, NL432, NL437R will run at their full brightnes (2.5V-6V range) while stationary on battery power only for almost 2 hours with fully charged 1000mAh cells.

Charge resistor R1 value must be chosen to avoid overheating the battery when fully charged. NiCd cells can accept over-charge as long as it is not excessive. Alternatively there are more sophisticated ways to control battery charging with IC chips. In this case other cell types such as NiMh or Li-ion could be considered.

This circuit could be adapted to produce a regulated bicycle 5V USB supply.

NOTE: Either the generator coil OR the bulb holders must be electrically isolated from the bicycle frame to avoid a short circuit at the bridge rectifiers (BR). Sturmey Archer Dynohubs and probably most modern hub generators are isolated from the bicycle frame.

COMING SOON:

LED CONVERSION CIRCUIT FOR MOPEDS & SMALL MOTORCYCLES WITHOUT A BATTERY, INCLUDING VELOSOLEX


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