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I'm looking for a dc-dc converter using only basic components (coil, condensator capacitor, transistor, resistor, diode, zener diode). Because when ordering a specialized component from the internet it usually takes 1 month to ship.

My electronics studies are way behind me, and I'm ashamed to say that I don't understand the two simple schematics that I will post. I can still manage digital systems but analog systems are something else.

I need 5V with 60mA max.

So far I found 2 schematics:

How could I increase the output power?

Does using a 5V zener diode give me a 5V output? How do I know how much current I can take from it?

Any other schematics?

JYelton
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sliders_alpha
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  • Whereabouts are you? What exactly do you have access to IC wise? (opamps? 555 timers? microrontrollers? linear regulators) Or is it only transistors? (bipolar and MOSFETs?) – Oli Glaser Aug 15 '13 at 21:23
  • France, it's just that electronics shop are not compatible with my working hours and I don't want to pay 15€ for shipping. I have access to opamps (lm358, tl062), npn and pnp, pic16/18F and lm312 as 7805 linear regulator, I have some Nmos and Pmos taken from here and there. – sliders_alpha Aug 15 '13 at 21:33
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    Roman black has designs for several nice two or three transistor DC/DC regulators. I don't see any that immediately fit the bill, but perhaps you can modify one of his designs. http://www.romanblack.com/smps/smps.htm – John Meacham Jul 08 '14 at 07:58

2 Answers2

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If the designing of a boost regulator is not the primary objective, use a pre-built boost module such as this one ($1 including international shipping from eBay):

Image

The module works with inputs from 0.9 to 5 Volts, and outputs 5 Volts at up to 600 mA.

Of course, you would have to wait 3 to 6 weeks for the delivery, but at the price, that might be worth it.

Anindo Ghosh
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  • I know but as I said in in my post, I can't wait 1 month so ordering from china is not an option. – sliders_alpha Aug 16 '13 at 06:07
  • Many of those sellers on eBay and DX.com do offer expedited delivery, sometimes for as little as $5 per shipment. You'll just need to put in the effort to examine the various options more carefully. Trade that off against the time you will take in perfecting a stable boost regulator circuit of your own. :-) – Anindo Ghosh Aug 16 '13 at 06:10
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This is also working good. You can experiment with part values.

Schematic

Ricardo
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hony004
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    What would be sensible values to start with for those components? What is the transformer? Will it be limited to 4V3 due to that diode? Some more details would probably help the original author. – David Jul 27 '14 at 13:33