Help with boost converter circuit

billybob

Active Member
I was messing around with a boost converter circuit and I'm trying to understand how I can milk more power from it without changing the input voltage.

I have a 3.7V lithium ion battery input and I would like the output to be a steady 9-12V able to draw at least 0.3 Amps.
Here is the schematic I used:
I ended up bridging the potentiometer completely, replaced R2 with 100ohm, Q1 is C9014, and I'm not sure how to accurately measure L1.

The output I'm getting is around 40-70V, but drops to 2.6V with a 100ohm load. The current drawn from the power supply says 0.27A.
What can I do?

 
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I was making a joke off of Nigel's persistence in telling me I need feedback lol.
Thank you for all of your help, I appreciate it.
 
I found that strange because it works with as low as 2.5V for me.
That far below the minimum supply voltage, it won't work nearly as well as if it's used as it is supposed to be used. At 2.5 V, it could well be that it doesn't work at all at different temperatures, or different batches of IC or other different conditions.
 
Maybe your 555 is a newer CMOS LMC555, TLC555 or ICM7555? The LMC555 guarantees working with a 1.5V supply, the other two with a 2.0V supply.
 
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