George -- Try going to www.ultracad.com Doug Brooks has a couple of articles on fusing and temperature rise plus a trace/current calculator posted there under "What's Available at this site?" that are very useful. Jeffrey A. McGlaughlin, C.I.D. Sr. PCB Designer Battelle Memorial Institute Columbus Ohio [log in to unmask] -----Original Message----- From: George Franck [mailto:[log in to unmask]] Sent: Monday, February 05, 2001 9:15 AM To: [log in to unmask] Subject: [TN] Did we design a fuse? Greetings, Where can I find additional information of heat rise vs conductor width and thickness? For example, a 5 sq mil (cross sectional area) internal trace will probably get subjected to a dead short sometime during its prototype testing life, and be called on to carry 1 amp for a little while. (How long is a little while? How ever long it takes the engineer to figure out they got a dead short.) The question is: Will it act like a fuse and vaporize? The last value in the chart in IPC-2221 (Figure 6-4), indicates a 45 C temp rise at about 400 m-amps for a 5 sq mil internal conductor. Thanks George Franck ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------