If-Off-Stay-Off Box, power loss safety device

thingiverse

The if-off-stay-off box is a cheap tool for protecting electro-mechanical devices from damaging themselves following a power outage by preventing them from turning back on when the power returns. If the if-off-stay-off is unplugged and re-plugged in then it will remain OFF until the button is pressed (then it will remain ON until unplugged again). I designed this for a friend who was worried about his fish tank filter pump, which needed manual priming to operate properly and would be damaged if allowed to run dry (which would happen following a power outage). Of course an uninterruptible power supply (UPS) is the preferred option for protecting devices during a power outage, but they also cost about $60. Perhaps you can think of alternatives uses for this device anyway; Practical jokes maybe? Instructions Make sure to use correctly sized wire and relay for your specific power requirements. You can find a free wire sizing calculator here: http://engineerdog.com/2015/01/05/free-electrical-wire-gauge-sizing-calculator/ In my experience project boxes are best printed solid or else the outer layer doesn’t bind well to the inside and you end up with a weak box. Version 1 uses a single pole single throw (or double throw) relay. Version 2 uses a double pole single throw (or double throw) relay and is recommended. Both versions use the same case. Shopping List: (1) 120VAC Socket Plug: http://amzn.to/1dYl2dr (1) Relay: http://amzn.to/1Jd1wra (1) Momentary Switch: http://amzn.to/1SBsQAZ (1) Three Wire Power Cord: http://amzn.to/1HszYrG