using buck converter

I have a 6V 3AMP power supply and I wanted to reduce the voltage output to 5V 3AMP.

I saw buck converted on ebay of the following spec. Can i use it to step down 6V to 5V without losing Ampere? or any suggestion, how i can step down 6V to 5V while keeping 3AMP.

DC-DC Buck Step Down Converter Regulator Power Supply Module 9V 12V 24V to 5V 3A.

Mini DC-DC Step Down Converter

Input voltage 7V~28V

Output voltage 5V(Precision 1%）

Output current 3A(max),long time work within 1.5A

Conversion efficiency 96%(max)

Output ripple <30mV

Switching frequency 1.5MHz(max), Typical 1MHz

• Not just can, you must. DC/DC will reduce voltage, while power on both sides will be almost the same, so disregarding it's own limitations output current may be even a little more. But pay attention, they say continuous current is 1.5A, meaning with 3A it will overheat. Maybe you will want to use some heatsink or choose more powerful DC/DC. Ah, and minimum voltage is higher than yours. Maybe it will work, but you can never know. – Gregory Kornblum Jun 21 '17 at 18:54

It says that the input voltage is a minimum of 7 volts and this means that it won't work correctly if the input voltage drops below 7 volts. Don't ask what might happen if you do run it at 6 volts because I won't be able to answer you. There are devices out there that should do what you want. Keep looking.

It also says that the peak current that can be delivered is 3 amps but the wording implies to me it can only deliver 1.5 amps continuously.

Here's a design from Linear technology that can do what you want with what looks like apparent ease: -

There is also this device too: -

And this: -

So, in conclusion, there are designs around and maybe you can find someone vending this as a finished PCB. There are similar offerings from Texas Instruments as well.

• Thank you very much. since using this buck converter is out of question, I might go for DIY - I have this old power supply with a rating of 6V 3AMP, what is the theory behind stepping down it to 5V and 3AMP. Any DIY project you can help me with? thanks a ton! – marc Katz Jun 21 '17 at 19:20
• Try googling buck converters. Basically if you switch some thing on and off rapidly, you lower the average voltage but end up with a square wave. If you filter it with an inductor and capacitor, you restore the shape to a dc representation of the average voltage. Switching, theoretically involves no power loss hence buck converters are efficient. Linear technology have a website feature where you can enter the input voltage range, the output voltage and current and they pick a list of suitable devices. – Andy aka Jun 21 '17 at 19:31

Don't be too hasty to buy Two buck converters ($2 or$1.97ca)

Your question indicates "9V 12V 24V to 5V 3A." but only rated for 1.5A peak not continuous.

Keep shopping , not just here..

you can just use the single or two diodes in series of about 6A or 10A (6A10) for droping 0.7V for each diode. at the output.without using buck converter.

• Thanks. If my need is 5 v and I use two diodes to drop 1.4 v, the resulting voltage will be 4.6V. Can this be used in 5V microcontroller projects? In this process will the Amp remain at 3 Amp, which is the input current? – marc Katz Jun 22 '17 at 9:55
• the 6V battery voltage is about 6.5V at full charge – Zahid Abbas Jun 30 '17 at 9:41