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DC-DC converter 1V to 5V

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nima_1981

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DC-DC converter 1V to 5V

Hi ,
I'm new in this forum , and in the fist relay sorry for my English writing .
i need Dc-dc Converter 1v To 5v but i can not use any chip for this problem , any one can help me ?
 

Your question is not clear. state what is your input source. Without providing input data, noone can understand and help you.
data's like power, current coltage, source type(ac/dc) ect are essential.
Hope you understand what i am trying to say,....
 

sorry you are right
my source voltage is 1V-2V From Dc Battery and that Battery Current is 900 Amp Per Hour . And i need Only 500 MA and 5 Volt Dc
Thank you
 

May i know, why you do not want to use PWM Ic's for this purpose?
 

yes , because i live in Iran and this parts is not available .
 

Its very difficult friend.
Its possible, but the circuit complexity will increase. If the source is Ac, it is easily achievable. since we can use diode voltage doubler circuit. for that we need only diode and capacitor. As the source is DC, either you can use DC-DC boost converter or convert dc-ac and then boost the boost the voltage. For DC-dc converter defenetely you need PWM IC for boosting and maintain voltage to be stable. for dc-ac conversion we need either PWM Ics or 4 relays and timer. and to boost you can use transformer and diode configuration.
I hope you understand
 

nima_1981 said:
can i do same as this :
ELM - Pocket LED light
thank you
Click to expand...

Do you understand the operation of the circuit?
I don't understand the configuration it. They are passing DC voltage into the primary of the transformer, How its possible? It will get saturate know ! I don't understand how transformer is working with DC voltage. And secondary winding is for biasing the transistor, if it biased, it will short circuited. I don't understand the circuit connection. Can u?
 

nima_1981 said:
can i do same as this :
ELM - Pocket LED light
thank you
Click to expand...
Yes that circuit will work - it is used a lot for low voltage input - you will need a good quality transistor if you want to get 500mA out though, and a well designed magnetic part suitable for the boost type application, you will need a shunt regulator on the ouput if you want an accurate 5VDC out, Regards, Orson Cart.
 
Last edited:

@Orson Cart
Here what is the purpose of transformer. Transformer is of opposite dot polarity. How this will helps to boost the input DC voltage?
What about the saturation effect? You are passing Dc current continuously into the transformer primary. How does it works !!! i am wondering. Can you explain this.....
 

It is a self switching boost converter, very common in low power electronics, but not as simple as it looks. It relies on the base drive stopping when the core starts to go into saturation, during the turned off phase energy goes to the output, then it starts all over again.
 

Orson Cart said:
It is a self switching boost converter, very common in low power electronics, but not as simple as it looks. It relies on the base drive stopping when the core starts to go into saturation, during the turned off phase energy goes to the output, then it starts all over again.
Click to expand...
How this switching over of power taking place, without the switching device?

---------- Post added at 12:08 ---------- Previous post was at 12:06 ----------
Orson Cart said:
It is a self switching boost converter, very common in low power electronics,.
Click to expand...
Is this self switching boost converter? How does it works, without saturating the transformer?. can you explain.....
 

The transistor is the switching device, the transformer does go into saturation briefly, once each switching cycle, when this happens the base drive reverses, the transistor turns off and most of the enery stored in the transformer flows into the load, when the current through the diode into the load falls to zero, the transistor is turned on again and the process repeats... Regards, Orson Cart.
 


Hi all
After 3 year i have this problem yet did you have a schematic for boost 2 volt to 5 Volt or 12 Volt Wihout PWM ic For 1 Amper Current?

 

If you want a -regulated- high voltage output then you need
all of the functionality of these integrated PWM regulators.
If you need only rough, much higher voltage then simpler
self-oscillating boosters could do. To make one of these
have good regulation, especially dynamic and with safety
features, would end up being more elaborate (to the board
level user) than an IC solution.

Problem is, very few power conversion ICs are made to
operate at such low line conditions - usually undervoltage
lockout to protect the power switches and ensure proper
internal operation is set much higher. You can't get a
bandgap reference at 1V, just getting a good error amp,
ramp and comparator at 1V is some serious work. May
be better to use the crude booster and regulate from the
rough raw high voltage with a cheap linear since the
desired current is low and cheap linear regulators are
perhaps more available. Something like the Joule thief
in cascade with a 78L05, and call it done (unless you
also wanted high efficiency along with your unobtanium).
 

did you have a schematic for boost 2 volt to 5 Volt or 12 Volt Wihout PWM ic For 1 Amper Current?
Click to expand...

Here is a simulation showing how a joule thief (or blocking oscillator) might step up 2V to 9V at 1A or so. It is only theoretical, of course. The practicality of it is another question.



The 2V supply must provide several amperes.

The transformer needs to carry 100 mA in the primary, and several A in the secondary. Since it can operate at high freq., it may not need a lot of metal in the core.
 
nima_1981 said:

Hi all
After 3 year i have this problem yet did you have a schematic for boost 2 volt to 5 Volt or 12 Volt Wihout PWM ic For 1 Amper Current?
Click to expand...

I've built several joule thiefs for a number of projects, but the most I've been able to draw reliably is about 1/2 watt. More than that, and one exceeds the current capabilities of small general purpose NPN transistors. (2N3904, BC317).
If one attempts to use a more powerful transistor, like a TIP31, its low beta does not give satisfactory results.
 
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