Jawa electrical gizmo ?

[R]

I've got amongst some stuff a Jawa battery box.
Looks like plunger frame era, early 1950s, bit crusty ?
Its got an electrical gizmo on top that could be a zener diode maybe ?
Labelled as USMERNOVAC JAWA  6V 1.5A

Anyone shed any light on this ?
9w doesn't seem like much to do anything useful with ?
Unless its quite a low output electrics all around !
There is a bit online on this - but its all in czech !



https://i.postimg.cc/MZf8TsF9/Jawa-batterybox.jpg

[Rex]

Can't you copy and paste the Czech stuff into Google Translate? Early 50s sounds too early for Zeners though. Maybe it's a half-wave rectumfrier?

[R]

You could well be right.
That may mean the bike ran ac electrics, and the battery was merely trickle charged - for parking lights ?
Villiers used a similar system when a battery was incorporated  ?

Good suggestion. I'm not even sure what language that is.
Last time I tried something like that, it made no sense.
Technical terms are often not in common translation usage /dictionaries.
I'll work on it.

[Rex]

Charging for parking lights sounds about right, as at a rating of 1.5A they clearly weren't expecting too much..

[john.k]

Tartan Manet scooter.