Not a micro controller problem But need help.

Hello i have a question that doesn't have to do with a micro controller. I'm working on a Emergency light project that doesn't require a micro controller. The problem I'm having is how to detect when the power goes out and turn on the lights. The lights are using a Lipo 18650 battery charged by a Tp4056. I'm not sure what to do to detect when the power is out without a micro controller. I'm a little lost can someone please help me?


A mains relay?

Hello Awol i can do that but I'm just using a 5V wall adapter to charge the batteries nothing else. So I'm trying to think of a way to detect that 5v line.


Use a 5 volt relay that is normally closed.

Hello Railroader. Oh i didn't think of using a 5v relay. I always in the past used one with a micro controller. But never thought of using one without a micro controller sense it can use a 5v on the Trigger. Thank you.

Edited: Thanks Awol and Railroad for the help.


Haha. "Keep it simple" I was told in a totally different subject. "Don't walk across the river to get water" is an other. Do things as simple as possble.

No wonder why my wife calls me Stupid all the time for not keeping things Simple LOL

Oops. Stupid? No! You just have more brain power then needed this time.
Sorry I pressed that button. Look for the simplest solution. Don't overdo things. The day wil come when You face those tasks. My solutions look terrible, they work, do their jobs but, they will not win any prices.

LOL that was a joke. My wife doesn't call me that. I was making a bad joke by kiss. keep it simple stupid LOL

Thanks! All is good then.