Workshop smoke alarm

Switched smoke alarm for workshop. LED off indicates smoke alarm is active.

knoba - workshop smoke alarm

~§~

LED flashing on indicates smoke alarm is deactivated.

knoba - workshop smoke alarm

~§~

It can get a bit smoky in my workshop!
knoba - lab tripod

~§~

Wiring.

knoba - workshop smoke alarm

~§~

knoba - workshop smoke alarm

~§~

~§~

Schematic file below.

knoba - workshop smoke alarm

~§~

Materials:
1 x Switch: 1A, spdt (single pole, double throw)
1 x Flashing blue LED: 10mm, 15mA, 3.2v
1 x 10mm LED holder/bezel
1 x Resistor: 470ohms, 1/4W
Wire: 7/0.2mm 
Small heatshrink tubing

~§~

knoba – Workshop Smoke Alarm Schematic – 2018.fzz

•••

http://www.homemadetools.net

Advertisements

Homemade toothpaste

knoba - homemade toothpaste

~§~

Chalk (aka; calcium carbonate, CaCO3)
knoba - homemade toothpaste

~§~

Sanding belt is used solely for my toothpaste.
knoba - homemade toothpaste

~§~

Hydrogen peroxide (dilute & use with caution!).
knoba - homemade toothpaste

~§~

Wiki – Chalk

Howstuffworks.com – Can you use hydrogen peroxide on your teeth?

•••