Should we use only the first part of a hyphenated compound word to coin an initialism/acronym?
E.g. would "on-site detector circuit" become OSDC or ODC?
Or does it depend on the particular hyphenated word?
There are plenty of posts on this site related to acronyms/initialisms, but I couldn't see one that directly addressed your question. However, a bit of sleuthing came up with the following.
First, note that OSDC and ODC are initialisms, as the capitals are not pronounced as a single word but instead are pronounced individually - see here.
Regarding hyphens, this answer quotes from the Chicago Manual of Style (CMS), and while the quotation doesn't explicitly refer to hyphens, it includes the following example:
[transmission-control protocol/Internet protocol (TCP/IP)]
Based on that example, it can be assumed that the CMS would render your "on-site detector circuit" as OSDC.