Contact
Corrections, questions about the content, and any other enquiries: please e-mail us.
Address
Enquiries about this site are handled at the address below.
Replies can take a few days. Depending on the nature of the enquiry we may not be able to reply.
Before you write
Errors in a formula or a result. Please include the page URL, the input values, and which output differs from what you expected. Confirmed errors are corrected and the page's last-updated date is revised.
Questions about the explanations. We do not review individual designs. Questions about the assumptions or the range of validity of a formula on the site are answered where we can.
Advertising and placements. This site uses a third-party advertising service. We do not accept individual ad placements or sponsored articles.
Reuse and quotation. Text and figures are copyright of the operator. Quotation with the page URL as the source needs no prior permission. Please do not redistribute figures or republish whole articles.
Your data
Values entered into the calculators are processed in your browser and are never sent to a server. You do not need to send us details of the circuit or board you are working on. See the privacy policy for details.
Last updated: 14 September 2026