Рет қаралды 1,675
The most frequent question about the joule thief is "what frequency does it operate at?" I've got 2 that were made from the same batch of parts and today I finally got the set up to measure it, so let's find out!
MATERIALS
- O-scope
- Joule Thief (x2) (2n2222 NPN transistor, black core, 22 and 11 windings, red LED)
The common "black" core used has a range of 1kHz to roughly 200 kHz, however they can go into the low MHz range. The 2n2222 has an hfe of 30-35, Emitter Base volt of 5 (I killed my no toroid JF by ignoring this), max op freq 250 MHz....
Note: Technically this is not a joule thief as is commonly made on the internet. It's a modified circuit from an antique transistor tester.