Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
Hi varunme,
The boost converter is highly efficient with wide input rating from 0.7 V to 5.5 V with a few components see the link given below https://www.ti.com/lit/ds/symlink/tps61220.pdf
I have seen torches with simple boost circuits, inductor and bjt's fedback with a capacitor to make oscillator. The current is set by leakage inductance and inductor on-time for discontinuous current. With the boost voltage clamped by the LED's own VI characteristics. Actually one 1.5V cell is enough for bipolar based designs.
The 3909 IC flashed an led from a single 1.5V battery. It charged a capacitor, then switched its polarity to add to the supplyV, thus is could power a 1.8V led.
The 3909 is obsolete because the same function apparently can be duplicated by more advanced circuits and IC's (although I don't know what number to look for).
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
