Joule Thief

[Pirate88179]

My Mom is old and is having memory problems.  She has been unlocking her door at night thinking it was unlocked when it was already locked.

So, I made this small JT circuit with a proximity sensor to show her in the dark if the door was locked or not.  She can see it from where she sleeps and the red led indicates that the door is locked.  Seems to be working so far for her.

This is the basic JT circuit with the 2N3904 and a ferrite bead instead of a toroid.  Sorry about the photo of the interior being blurred, have no idea why that happened.

Bill

[conradelektro]

@ Bill (Pirate88179):

I like the reed switch idea.

Greetings, Conrad

[Pirate88179]

Conrad:

Thanks.  It was the only thing I could find locally that would work.  It is the switch part of one of those security sensors they put on doors in sets.

Bill

[crowclaw]

@ Bill,
Well done Bill, at last another really useful and practical use for the JT circuit. This is helping someone to recognise enhance their security and ensuring your peace of mind... top man. M

[Pirate88179]

crowclaw:

Thank you very much.  I too love practical everyday uses for this circuit.  I am sure there are many more out there waiting to be thought of and made.

Bill