Hi artful, please see the following:
At I = 50mA, Vf = 2.45V
At I = 30mA, Vf = 2.26V
[Brake Light] (+) -- 7809 -- diode ---------┐
[Tail Light] ...(+) -- 7809 -- diode -- 5R6 --•-- 22R -- LED -- LED -- LED ---•-- (-)
.................................................. ..........└-- 22R -- LED -- LED -- LED --┘
.................................................. ..........└-- 22R -- LED -- LED -- LED --┘
.................................................. ..........└-- 22R -- LED -- LED -- LED --┘
.................................................. ..........└-- 22R -- LED -- LED -- LED --┘
.................................................. ..........└-- 22R -- LED -- LED -- LED --┘
Diode = 1N4007, all resistor @ 1/4W 1% tolerance
For voltage regulator:
[Brake Light]---->(Vol IN)7809(Vol Out)---->diode
Connect GRD (center pin) to negative.
---------- Post added at 01:33 AM ---------- 6 hour anti-bump limit - Previous post was at 01:16 AM ----------
After you wire up everything, and when first power on, use a volt meter to make a quick measure the voltage drop across one of the 22R resistor.
At Tail Light function, you should have 0.6V~0.7V (27mA~32mA)
At Brake Light function, you should have 1.0V~1.1V (45mA~50mA)
If the reading is far beyond the range, you might want to disconnect the power immediate and re do the calculation.