1. Generally, Avalanching is the dominant source while the Zener process occurs only when the junction is doped heavily on both sides

2. In silicon diodes up to about 5.6 volts, the Zener effect is the predominant effect and shows a marked negative temperature coefficient.

3. The output voltage is determined by the Zener diode (VR voltage and the voltage drops across the optocoupler (U LED and resistor R

4. Other modifications were Amal alloy (aluminium) control levers with click-stop cable adjusters, production of which BSA took over from Amal, marketed under their 'Motoplas' accessories branding, and the Zener diode voltage regulator was installed in an aluminium heat-sink mounted high on the front frame tubes to benefit from the cooling airstream.