High Efficiency DC Converter Specification Example for Passenger Cars: Sealed Unit
High Efficiency DC Converter Specification Example for Passenger Cars: Sealed Unit
This is a worked specification for high efficiency dc converter in a sealed unit programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The sealed unit version exists because the duty cycle on passenger cars is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually warranty claims traced back to a single lot.

Example specification
| Item | High Efficiency DC Converter |
|---|---|
| Application | Passenger Cars |
| Version | Sealed Unit |
| Base material | Bronze |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | zinc plated |
| MOQ | 1,000 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | TUV |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Bronze, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- shot blasting
- heat treatment
- electroplating
- ultrasonic cleaning
- gravity casting
- rubber vulcanisation
Where this example applies
Programmes that run sealed unit most often specify this build for passenger cars. Related applications include boat trailers, construction equipment, three-wheelers, rental motorcycles, light trucks.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 1.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
What testing is included?
Standard lots ship with dimensional and hardness reports. TUV documentation is issued with the shipment when your market requires it.
What is the minimum order quantity?
The standard MOQ is 1000 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.



