I have an adjustable power supply of 150W.I want to power two peltier modules of 12v/6amps and 12v/3amps and two fans each of 12v/0.72amps.
Please suggest me an efficient way to power all devices.

 

Do the math. The boost board you show is limited to 6A. The devices you want to power add up to 10.44A.

Most efficient? Use a 12 V battery or power supply capable of at least 12A.

 

Do the math. The boost board you show is limited to 6A. The devices you want to power add up to 10.44A.

Most efficient? Use a 12 V battery or power supply capable of at least 12A.

Can I connect these devices in series

 

Can I connect these devices in series

You could, but it will still be limited to 6A. Why are you fixated on using the wrong power supply for your project?

 

A 12Vdc supply capable of delivering 10A will be able to power all the devices.

What were you proposing as the input to the boost converter?

 

A 12Vdc supply capable of delivering 10A will be able to power all the devices.

What were you proposing as the input to the boost converter?

It might, but you will be exceeding it’s max current spec. That why I suggest 12A, giving you a little margin.

 

You could put the 3 amp Peltier device in parallel with both fans and then put that in series with the 6 amp peltier device, and adjust the power supply voltage to deliver exactly 150 watts. BUT I do not advise that, unless the supply is rated to deliver rated power continually. That could be a "Mil Spec" rating, maybe.