This was found in a electric eye operated night light. It's either a sensitive gate SCR, or one with a built in diac.
The markings on the TO92 package are:
4010 ST (logo) T551Appreciate any info.
Thanks.
--- sam | Sci.Electronics.Repair FAQ:
formatting link
Repair | Main Table of Contents:
formatting link
+Lasers | Sam's Laser FAQ:
formatting link
| Mirror Sites:
formatting link
Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.