DIN 33958

This 'standard' had been first used to approve some 1.5 W dynamos in StVZO, which is possible by virtue of the possibility to deviate from the requirements in TA, as described in TA.1.2. So devices can be approved according to StVZO+TA, or any other standard that is deemed suitable, and DIN 33958 is the first one.

Notes: 1. The light institute mentioned that the products are approved according to StVZO+TA even if another standard is used, but of course not all rules in TA are used. So the actual situation is best described in this case by: StVZO + TA.1.2 + DIN 33958.
2. The light institute decides on when to use a different standard than the rules in TA, this means that the 3W rules in DIN 33598 are NOT used to approve any bicycle lamps or dynamos...

There have been some dynamos released for this standard and recently some taillamps and headlamps. The Herrmans H-black pro for example. But what is the f-ing point? We need more power, esp. from the dynamo, for e.g. USB power and better lighting. With high efficiency dynamos it also doesn't matter much if you put out 3W or 5W at a given speed, any cyclist can supply the required power (at say 66% efficiency (a nice round number if you get my point, and most good dynamos perform not far from that, some a bit better others slightly less), this would mean 1.5x 3W or 1.5 x 5W, so 4.5 or 7.5W. You will not notice a speed drop from 3W extra... The argument that the dynamos can be made cheaper doesn't make sense, Shimano has very cheap 3W dynamos and the 1.5 W dynamos that I've seen are not cheap at all. Lower weight is also not really an argument as the 1.5W dynamos that I've seen by Shimano are actually heavier than e.g. SP 3W dynamos...

I will examine this standard in Dec. 2017 and will write a summary here.

Analysis of DIN 33598 (2014-12-00): The start

The numbering system is good.

4.1.1: It mentions that "the light source must be fixed. However, if it isn't fixed then in all its positions it must fulfill the requirements in the text". Say what? This isn't a formulation that should appear in a standard as strictly speaking it is contradictory. That is informal talk! 1.5W system headlamps must not go over 2.0 lux in the region 3.4 degrees above the maximum intensity, even using a 3W system. That makes sense as they could be used on 3W dynamos inadvertently or on purpose!

4.3.1: The dynamos for 1.5W systems are listed as 'LED-Dynamos'. Hmmm... Why? The light source is really irrelevant and shouldn't be used in the name.

Sidewall (or rather friction driven) dynamos and hub dynamos (direct driven dynamos) are considered separately but the only difference is the required efficiency, a quite low 0.20 for sidewall dynamos.

Differences between TA and DIN 33958

To come.

Preliminary conclusion

I'm not really impressed by this standard. Not in how it is presented nor in wording nor in doing/saying what makes sense... It is a lot more readable than the technical rules in StVZO/TA but that was just horrible so it is not saying much that it's better than that.

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