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Hi everyone..I'm trying to build a Joule Thief circuit operating on a 1.5V cell. Which transistor should I use? I have BC547 but I'm not sure it will work...Suggestions are welcome..
Joule Thief -- Which transistor should I use?
- Thread starter cnh1995
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- Joule Transistor
In summary, a Joule Thief is a simple electronic circuit used to boost low-voltage input to a higher voltage output for powering small devices. It works by using the inductive kickback from an inductor and can be built with various transistors, such as the 2N3904, 2N2222, or PN2222. A MOSFET can also be used, but must have a low threshold voltage and high drain-source breakdown voltage. When choosing a transistor for a Joule Thief, factors such as current gain, breakdown voltage, and power dissipation should be considered. Experimentation may be necessary to find the best combination for a specific circuit.
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davenn
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google is a wonderful thing 
http://www.bing.com/images/search?q...+circuits&qpvt=joule+thief+circuits&FORM=IGRE
there's a whole mass of joule thief circuits with the components used
take your pic and try some out
Dave
http://www.bing.com/images/search?q...+circuits&qpvt=joule+thief+circuits&FORM=IGRE
there's a whole mass of joule thief circuits with the components used
take your pic and try some out
Dave
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1. What is a Joule Thief?
A Joule Thief is a simple electronic circuit that can take a low-voltage input and boost it to a higher voltage output. It is often used to power small electronic devices, such as LED lights, with a single battery.
2. How does a Joule Thief work?
A Joule Thief works by using the inductive kickback from an inductor to create a higher voltage output. This is achieved by rapidly switching the flow of current through a transistor, which causes the inductor to build up a magnetic field. When the transistor turns off, the magnetic field collapses, creating a spike in voltage.
3. Which transistor should I use for a Joule Thief?
The most commonly used transistor for a Joule Thief is the 2N3904 NPN transistor. However, other transistors such as the 2N2222 or PN2222 can also work well. The key is to use a transistor with a high current gain (hFE) and a breakdown voltage (BVCEO) of at least 30V.
4. Can I use a MOSFET instead of a transistor for a Joule Thief?
Yes, a MOSFET (metal-oxide-semiconductor field-effect transistor) can also be used in place of a transistor for a Joule Thief. However, it is important to choose a MOSFET with a low threshold voltage, typically less than 3V, and a high drain-source breakdown voltage (BVDSS) of at least 30V.
5. What are some tips for choosing the right transistor for a Joule Thief?
When selecting a transistor for a Joule Thief, it is important to consider its current gain (hFE), breakdown voltage (BVCEO), switching speed, and power dissipation capabilities. It should also be able to handle the current and voltage requirements of your specific circuit. Experimenting with different transistors and adjusting the circuit components can help you find the best combination for your needs.
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