Last Updated: 2026-10-05
দ্রুত উত্তর: A DC-DC converter input-window handover should preserve the complete model, its documented input window, the actual unit label and any unresolved differences between them. For the WEHO SD-50B-12 reference here, the B input window is 19–36 VDC. The photographed unit says 12 V, 4 A; the published SD-50 specification lists 12 V, 4.2 A. Those are separate records, not interchangeable approvals. Resolve the ordered configuration before releasing the purchase or the unit for service.
Why the input suffix belongs in the purchase record
A purchase description such as “24 V input, 12 V output converter” is useful for an initial conversation, but it is incomplete as an order definition. The nominal source voltage does not identify the full allowed input window, the exact unit, or the documentation that engineering reviewed. When purchasing, engineering and receiving each shorten the description differently, an apparently minor omission can remove a meaningful model distinction.
The purpose of this article is a controlled handover, not a converter-sizing calculation. It does not select a load, claim that a vehicle or battery system is compatible, or prescribe a finished installation. It shows how a buyer can carry the evidence from technical review into a request for quotation and then compare the incoming item with that record.
Use the SD-50 family table without losing the exact variant
The WEHO SD-50 documentation distinguishes three DC input ranges: A is 9.2–18 VDC, B is 19–36 VDC, and C is 36–72 VDC. The family also contains multiple output variants. The complete SD-50B-12 identifier therefore carries information that disappears when a requisition retains only “SD-50” or “12 V converter.”
Record the suffix as part of the manufacturer model, not as an optional free-text comment. Put the reviewed input range next to it so another person can check whether the quotation, supplier response and incoming label refer to the same selection. Do not infer that similarly named models across different power families use identical suffix meanings; read the relevant family table.
The input window is a documented product boundary, not a measured description of the customer’s DC bus. Engineering still needs a separate source-system record. That record should identify who supplied the minimum and maximum source-voltage information, what operating conditions it covers and what is still unknown. A purchasing handover should preserve uncertainty rather than quietly substituting the nominal 24 V value for missing evidence.
Keep the physical label separate from the published table
The photographed SD-50B-12 unit in this article is marked INPUT DC24V(19–36V) 3A and OUTPUT +12V 4A. The published SD-50 specification gives the 12 V output group a 4.2 A rated current and 50.4 W rated power. These observations must not be combined into a claim that the photographed unit has been verified at 4.2 A.
There is no need to guess why the records differ. A photograph, a published family sheet and a particular ordered configuration may require reconciliation, and the reason is not established merely by looking at them. Do not label the photograph “an old revision,” assume a printing error, or upgrade the physical rating from a marketing caption without confirmation.
The practical purchasing question is precise: which output rating and document revision apply to the exact unit being supplied? Send the complete model, the relevant sheet and a readable label photograph when asking the supplier. Until the answer is recorded, keep the discrepancy open. Multiplying 12 V by either current value is arithmetic; it does not provide a load test, thermal qualification or release decision.
A handover record with six useful fields
First, record the full manufacturer and model exactly as supplied. Preserve punctuation and suffix characters sufficiently to avoid ordering a different unit. Do not replace the model with an internal nickname unless the internal stock number also resolves unambiguously to the manufacturer record.
Second, identify the input evidence: the published window, the photographed input marking and the source-system information supplied by engineering. Label each item by its source. A manufacturer’s range and a customer’s measured or specified bus range answer different questions, so neither should overwrite the other.
Third, record the output evidence, including any mismatch such as the 4 A photograph and 4.2 A table in this example. A quotation that repeats only “50 W” does not resolve this difference. Ask for the ordered model’s actual output rating and applicable conditions rather than relying on a broad series name.
Fourth, preserve the connection definition. The retained SD-50 mechanical drawing identifies five terminal positions: DC input V+, DC input V−, FG, DC output V− and DC output V+. The reference is an enclosed terminal-block converter, not a fixed-wire module. Receiving can document visible terminal form, but the drawing is not permission to connect an unverified unit or improvise a wiring arrangement.
Fifth, attach the mechanical document. The retained drawing gives 159 mm length, 97 mm width and 38 mm height. Another publicly available SD-50 sheet shows a 98 mm width, which is another reason to confirm the ordered mechanical revision rather than treating a generic family download as an exact mounting contract. Exterior dimensions do not establish required ventilation or wiring clearances.
Sixth, name the unresolved actions and their owner. A record that says “checked” but does not identify the document, model or open questions is difficult to use at receiving. A short discrepancy list with a named engineering or supplier contact is more useful than an unsupported approval stamp.
Receiving should compare evidence, not silently reinterpret it
At incoming inspection, compare the delivered label and model against the purchase record before treating the item as a service-ready spare. Photograph the readable marking, preserve the shipment’s relevant identification and note any difference in terminal form or enclosure features. This is an evidence capture step, not a powered acceptance test.
Do not let a warehouse operator resolve an electrical discrepancy by choosing whichever number appears more convenient. If the order calls for one confirmed rating and the supplied label presents another, route that difference to the responsible reviewer. Likewise, matching appearance does not establish the applicable input window or prove that internal electrical performance is identical.
The images illustrate disconnected documentation and receiving activities. They do not show a qualified installation, a test result or an energized converter. The loose scale reference is only an illustration aid; it is not a measurement certificate or a mounting accessory for the product.
Separate documentation closure from engineering release
Supplier confirmation can close a documentation question, but it does not by itself qualify an application. The project still needs its own review of source conditions, output demand, installation and applicable tests. Conversely, a successful trial with one sample should not erase the model and revision details needed for repeat procurement.
A useful release trail therefore links three things: the exact item ordered, the evidence used to accept that item, and the project-specific decision about its intended use. Keep those decisions distinguishable. That makes later substitutions and repeat orders easier to assess without pretending that one photograph proves the whole system.
Frequently asked questions
Does SD-50B-12 mean any nominal 24 V source is acceptable?
No. The documentation identifies a 19–36 VDC B input window. The actual source-system conditions still need their own engineering evidence and review; a nominal value alone is not a compatibility approval.
Should the photographed 4 A label be rewritten as 4.2 A?
No. Preserve what the physical label actually says and show the published 4.2 A entry separately. Ask which rating applies to the ordered configuration. Do not change a label image or use the larger figure as an assumed upgrade.
Is a matching enclosure enough to accept a substitute?
No. Appearance cannot establish the model suffix, electrical rating, terminal definition or applicable documentation. Retain the complete order identity and review any proposed substitute against the actual project requirements.
Does resolving the supplier paperwork make the converter ready for service?
Not automatically. Documentation closure and application qualification are different decisions. Receiving evidence should feed the responsible engineering review, not replace it.
মূল গ্রহণ
- Keep the complete SD-50B-12 suffix in the purchase record.
- Separate published input limits from the customer’s source evidence.
- Preserve the photographed 4 A label and published 4.2 A table as different records until resolved.
- Do not treat receiving paperwork as powered acceptance or application qualification.
উপসংহার
A DC-DC converter input-window handover is complete only when the model, source evidence and unresolved questions remain traceable across departments.
For a repeatable DC-DC converter handover, send WEHO the full model, the source-system information available, the required output conditions and the exact documents or label photographs that need reconciliation. Consult the WEHO SD converter family and the published SD-50 specification, then contact WEHO to confirm the configuration for the intended order. Keep unresolved differences visible until the responsible parties close them.
প্রায়শই জিজ্ঞাসিত প্রশ্নাবলী
Does SD-50B-12 mean any nominal 24 V source is acceptable?
No. The documentation identifies a 19–36 VDC B input window. The actual source-system conditions still need their own engineering evidence and review; a nominal value alone is not a compatibility approval.
Should the photographed 4 A label be rewritten as 4.2 A?
No. Preserve what the physical label actually says and show the published 4.2 A entry separately. Ask which rating applies to the ordered configuration. Do not change a label image or use the larger figure as an assumed upgrade.
Is a matching enclosure enough to accept a substitute?
No. Appearance cannot establish the model suffix, electrical rating, terminal definition or applicable documentation. Retain the complete order identity and review any proposed substitute against the actual project requirements.
Does resolving the supplier paperwork make the converter ready for service?
Not automatically. Documentation closure and application qualification are different decisions. Receiving evidence should feed the responsible engineering review, not replace it.
