power conversion understanding

So I have been working on a project for some time now and I have gotten the project its self down to 5v 500ma. I don't really think I can get the project its self down any lower in terms of amperage. however the end game power supply for the project is 14v 300ma i have been trying and trying to get down to that 300ma mark with my bench supply but the circuits needs are just too great. I have even tried using super capacitors to burst the 500ma when its really needed but to push that further will ultimately make the device too large and too heavy to handle the near constant draw for the length of time necessary. I understand alot about AC and if an Arduino and the rest of the project ran off AC this would be easy. Drop in a transformer calibrated to the right ratio turning my 14 volts to 5 volts and I would have an over abundance of amperage as the transformer drops voltage and raises amperage maintaining the same relative wattage. there is not enough room to convert dc to ac thrown in transformer and back to dc. At least not as far as I am aware and as far as I am aware transformers are only ac. i am not that well knowledge in dc circuits so the answer could be staring me right in the face and i have all the components necessary with say a voltage regulator. using a different power supply for the end project is out of the question doubling up the power supply is out of the question as well as the power supply would have to meet all the needs and this power supply was chosen cause it meets 99% of the needs except this one witch i figured i could work around and i have had no luck in finding anything threw google or anything probably because my education in dc circuits has too many holes.

Does any one have any ideas or suggestions how I could do this with minimal space?
is there such thing as a dc transformer that would atleast drop it to 7v 600ma?(i could easily work with that)

A switching "DC-DC converter" or "buck converter" can be nearly 100% efficient. For example, if you have 5V out drawing 500mA, you could have 14V in at about 180mA.

so just so I am understanding this its as simple as taking this buck module I already have that drops to 5 volts 2 amps and using it between my 14 volt power supply and the rest of the circuit? and it works in a like manner of wattage conversion as an ac transformer?

Please provide details of "this buck module I already have". You didn't mention it before.

The answer is PROBABLY yes because a switch-mode DC-DC (buck) converter acts for DC a lot like a transformer for AC. I.e. power (wattage!) stays fairly constant so decrease the voltage and you increase the current.

Steve

That
For those who dont want to click the link
"6 Pack LM2596 DC to DC Buck Converter Voltage Regulator 3.0-40V to 1.5-35V High Efficiency Power Supply Step Down Module by Lanpu "

I have a few of them in constant use. I have 1 hooked up to a near identical power supply 14v 300ma cell x 4 for a 14v 1200ma power supply set to 12v with a 5v liner regulater for the arduino (that project only needs 1amp 12 volts i think at this point it might be overkill for powersupply for that project given new information

One of those set to 5V output is just what you need.

Steve

thank you both so very much..... you have opened up a can of worms on my workbench to the tune of i have gone back to some older projects and rebuilt them because i have been using bucks all wrong