[andresp]

Ai pakub:

This is a vintage Bosch DC dynamo (direct-current generator), made in Germany, probably from the pre-war period.
The two additional photographs reveal important identification markings:

• Manufacturer: BOSCH
  
• Country: Germany (Made in Germany)
  
• Type marking: Appears to read
  
  Kood:

  D-JVE 4 90/12-1100
  (some characters are obscured by corrosion).
  
• Construction: Cylindrical DC generator with a belt pulley and an external mounting bracket.
  

It is likely from a German vehicle or engine installation, but the Bosch marking alone does not yet establish the exact car model.
Identified vehicle: Phänomen Granit 25 H



I found an exceptionally close, likely exact match in a historical technical specification.
The Phänomen Granit 25 H (1936–1939) used a Bosch generator listed as:

Kood:

RJVE 4. 90/12 . 1100RS 112

This matches the identifying sequence visible in your attachment.

motomuseum-hostalek.cz

The generator is rated at 12 volts and 90 watts, roughly 7.5 amps at rated output.
Conclusion: Your generator is very likely a Bosch RJVE 4 fitted to a Phänomen Granit 25 H truck. The same generator family may have been used in other German vehicles, so the truck is a documented application rather than proof of its original vehicle.
The historical reference is available here: Phänomen Granit 25 H technical specifications.