I have a small board for a 555 timer. You could populate it, power it from a wall wart, and put the relay inside an appropriate electrical box. I used to have relays that mounted on the cover of an electrical box with the contacts inside and the coil wires outside but I haven't seen anything like that in a very long time. Send me a mailing address offline and I'll send you one to play with. Allen -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of David C Brown Sent: Thursday, July 19, 2018 3:08 PM To: Microcontroller discussion list - Public. Subject: [EE] Is this safe? https://www.amazon.co.uk/s/ref=3Dnb_sb_noss?url=3Dsearch-alias%3 Daps&field-keywords=3DAC+220V+Timer+Delay+Switch+Module+Input% 2FOutput+Turn+Off+Board+Time+ I need a timer to control outdoor lamps on my "estate". Using a module like the one above would have the advantage that the operating switches - all outdoor - would be at a low voltage, meaning that the wiring is less onerous. But my concern is that the isolation between the 240vac and the the "cold" trigger terminals may not be adequate. My worry is that a failure could put the 240v onto the trigger wires. Looking at the pictures there is obviously no full isolation between 240v and low voltage , nor can I see a properly rated capacitor.. Comments welcomed __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb *Sent from my etch-a-sketch* --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .