Following BigCliveDotCom's YouTube video, I was able to build a joule thief.

I then built a HC-SR501 PIR Motion Sensor lighting a 4.5v string of LED fairy lights powered by either a 5v wall wart. or a 3 AA battery pack.

Now, I'd like to "marry" the two, and have the joule thief power the PIR sensor. But, I keep stumbling over the fact that a joule thief turns on and off thousands of times a second. The PIR has to have a constant current.

I've seen Lionel Sear's video and article about powering an electric wall clock via a joule thief here, but that uses only 1.5v, whereas the PIR requires 3.3-12v.

Question: Is it possible to charge a capacitor via the joule thief circuit, which simultaneously powers the PIR, and lights the LED string when motion is detected?

A suggested parts list would be nice. A circuit would be fantastic! Thanks for any ideas, thoughts, and suggestions!


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