firefly99
Enlightened
- Joined
- May 22, 2005
- Messages
- 748
I had made several attempts to make Joule thief but all ends in failure.
I had search through web & finally decide to use the following circuit.
My 1st attempt to use surface mount device & reflow.
White LED on left PCB, Blue LED on right PCB. The 2 orange thing is the LL4148 diode. The brown rectangle is the capacitor. The black rectangle below is the 5.6kohm resistor. Bottom left is either a 2N3904 or 2N2222A transistor.
Noticed that if I use a 12V A23 battery or 2 AA battery or 9V battery, I could get LED would light up.
But nothing happen when using a single AA or AAA battery.
1st question, what is the purpose of the 2 piece of LL4148 diode ? Circuit should work without these 2 diode.
2nd question, the schematic recommend a MPSA06 transistor. From many internet web pages, it seem 2N3904 or 2N2222A NPN transistor is ok. I had tried both 2N3904 & 2N2222A withour success.
I had a hard time winding the toroid coil. Believe there must be an surface mounted alternative. I am using 2 pieces of 100uH surface mount inductor coil, flat rectangle shape, look like a SMD resistor. The grey rectangle on the right side of the LED & the grey rectangle at the top of pcb at right angle.
Seem there are other surface mount inductor that is more bulky look like a tiny toroid coil.
3rd question, Which type of surface mount inductor to use a) flat rectangle 1206 size or b) more bulky tiny toroid coil.
Any advice would be greatly appreciated. Thank you
I had search through web & finally decide to use the following circuit.
My 1st attempt to use surface mount device & reflow.
White LED on left PCB, Blue LED on right PCB. The 2 orange thing is the LL4148 diode. The brown rectangle is the capacitor. The black rectangle below is the 5.6kohm resistor. Bottom left is either a 2N3904 or 2N2222A transistor.
Noticed that if I use a 12V A23 battery or 2 AA battery or 9V battery, I could get LED would light up.
But nothing happen when using a single AA or AAA battery.
1st question, what is the purpose of the 2 piece of LL4148 diode ? Circuit should work without these 2 diode.
2nd question, the schematic recommend a MPSA06 transistor. From many internet web pages, it seem 2N3904 or 2N2222A NPN transistor is ok. I had tried both 2N3904 & 2N2222A withour success.
I had a hard time winding the toroid coil. Believe there must be an surface mounted alternative. I am using 2 pieces of 100uH surface mount inductor coil, flat rectangle shape, look like a SMD resistor. The grey rectangle on the right side of the LED & the grey rectangle at the top of pcb at right angle.
Seem there are other surface mount inductor that is more bulky look like a tiny toroid coil.
3rd question, Which type of surface mount inductor to use a) flat rectangle 1206 size or b) more bulky tiny toroid coil.
Any advice would be greatly appreciated. Thank you
Last edited: