Simple Boost Converter

[Overclocked]

This is So Simple, Its Stupid, Yet it took a while to find. Someone Else already did it, But I had to confirm it works.

Idea came from here:https://www.anothercoilgunsite.com/nf-portable-construction.htm

Ive always wondered if A 555 Can be used to make a boost converter circuit, But My experimentation Confirms it. Some years Ago I bought this package of Inductors at radio shack, and Ive had them for a while. Using Values I just picked out of the Box, I got up to 50V From a 5V PSU. Sure, You can buy A Controller to Do this, But This is something you can build with parts from your box.

Note: I didnt worry about the Regulator and Stuff, I just used a Power NPN on the output of the 555. I also tried it with a Homemade Coil and Got up to 30 V. BTW, My NPN Got Hot during the process, but I didnt have it heat sinked, and this was During Measurement.

ADD: Heatsinked It and Its Cool.

Also, I dont know how much current this circuit can supply, But it looks like we might have another Joule Thief on our hands!

Values I used: C=0.001uF, R1, R2 = 5.6k . Vbias= 8.6 ohms.

 

[blueroomelectronics]

The site is run by another member here donniedj
https://www.electro-tech-online.com/members/donniedj.html
Small world

 

[Overclocked]

The site is run by another member here donniedj
https://www.electro-tech-online.com/members/donniedj.html
Small world

Well I'll be...lol

The Homemade Coil I have is about 7.22uH, which is an estimation from my calcs. If anyone wants to Confirm, heres my coil data:

Length: 1.575 Inches (40mm)
ID: .375 Inch (9mm)
OD (includes the Former):1.06 inch (26mm)
2 Layers, 14 Turns Each. Total of 28
AWG Used= 17 AWG

hmm and this gives about 30V Out @82Khz (for some reason though, I get strange jumpy readings at the transistor) . I am using a normal Silicon Rectifier (1N4007),which I know I should use. I dont have any Through Hole Schottky Diodes on hand, but I have SMD. Its kind hard to breadboard with SMD....

The regular 555 Timer can go down to a voltage of 4.5V, but a 7555 Timer can go down to 2V. Im sure there are Other clock chips that can go lower, Or we could just bootstrap the Output to VCC....I dont have many classes tomorrow, So I'll see if this thing can be used to power LEDs....once I replace the transistor of course

 

[Krumlink]

Lol check out my joule theif under **** chat (for some stupid reason!!!)

 

[mneary]

my joule theif

uhhh... yours?

 

[Nigel Goodwin]

Lol check out my joule theif under **** chat (for some stupid reason!!!)

Because it's a pretty crap copy of someone elses work, NOT a project of yours!.

 

[Torben]

Lol check out my joule theif under **** chat (for some stupid reason!!!)

Holy crap. Look, I know I defended you a few weeks back, but man--give credit where credit is due. You had nothing to do with that circuit, and barely acknowledge the guy who did design it. Retyping (and poorly) what is already written about it doesn't count.

You thank the people who actually did the work on youe projects, but did you ask them before posting their work?


Torben

 

[Overclocked]

It seems all this circuit is good for is charging caps..Added some LEDs (9 in series) to see if the reg would supply it. Nope! It dropped down to 3V Right away. Unless some sort of comparator is added, there is no way this circuit can be useful for anything other than charging caps.

 

[Hero999]

Holy crap. Look, I know I defended you a few weeks back, but man--give credit where credit is due. You had nothing to do with that circuit, and barely acknowledge the guy who did design it. Retyping (and poorly) what is already written about it doesn't count.

You thank the people who actually did the work on youe projects, but did you ask them before posting their work?


Torben

Leave him alone, it doesn't look like he's claiming credit for someone else's idea but describing his experiances with building someone else's project.

 

[Krumlink]

I completely dont claim credit! It is just a misfigure of speech! On my website, it says I give credit to the guy, I mean it even has his website and stuff on the picture! I diddnt blank that out, so why are you yelling at me!

 

[Torben]

I completely dont claim credit! It is just a misfigure of speech! On my website, it says I give credit to the guy, I mean it even has his website and stuff on the picture! I diddnt blank that out, so why are you yelling at me!

I'm sorry for being overly harsh in my earlier post, and I apologize. I still think it is not made nearly as clear that the work is someone else's as it is in the second circuit on that page, where you actually state that it was someone else's work. This one just states that it's not custom, and thanks Dick Cappels (for something; you'd have to visit his site to discover what). Most times author attributions are a little more explicit than that.

Anyway, I shouted when I should have spoken softly and for that I apologize.


Torben

 

[mneary]

Proper credit would look something like this:

"I recently built the circuit on Dick Cappels web site (scroll to "rusty Nail Night Light"). Here are some pictures and measurements...."

 

[Krumlink]

Ok, I will edit that into my website, watch and see!

 

[Overclocked]

Scratch that last Post. That was unregulatedtest, without a capacitor added. I added one 1,000uF Cap in parallel with the output and output voltage steadily increased. However, Upon adding the load (which is 10 White LEDs In series with 1 Current limiting resistor which has a value of 270 Ohms) The whole branch Voltage Was a Steady 28.2V.

It seems once more current is being consumed the voltage goes down. The only way to solve this would be to use a comparator and a voltage reference source to send a signal to the 555 and tell it to increase duty cycle or frequency.

 

[mneary]

I added one 1,000uF Cap in parallel with the output

For driving LEDs up to 100 mA, any capacitor more than about 100 nF (0.1 uF) should be as effective.

 

[gbmewada]

You buddy Have u seen that site???

It seems all this circuit is good for is charging caps..Added some LEDs (9 in series) to see if the reg would supply it. Nope! It dropped down to 3V Right away. Unless some sort of comparator is added, there is no way this circuit can be useful for anything other than charging caps.

See budy go on that site and see application of 555
If u r ture electronics guy u can find one most common req for SMPS design.
HUHHH.

 

[yrk]

Boost with the LTC555

Hello,

I need to build a boost circuit that boosts 3.7V to 5V and 12V. I was thinking of using the low power version of the LM555, the LTC555. It can operate at only 2V, and can work in the astable mode. However, I'm concerned about the output current bringing down the boosted voltage. The last time I made a boost circuit with the 555, it boosted 4.8V to 100V. However, when I applied a load, the current drawn reduced the boosted voltage to 14V. How do I ensure a constant voltage output irrespective of the current being drawn, or how can I limit the output current, so that the output voltage is unaffected?

Thanks!

 

[mneary]

It's tempting to use the 555 for everything, but it's a lot easier to use a chip designed as a boost converter. Try the selection guides at Linear Tech and at National.

 

[yrk]

I've already looked at several ICs on linear.com. However, the circuit we're designing needs to be very cost effective, and the LTC555 can help us achieve that. Is there a way the output voltage can be regulated irrespective of the load resitance?

 

[mneary]

How much current do you need at 12V? At 5V?