How to power a 12V6A peltier device with a 14.4V battery.
My son is working on a school science project and unfortunately I have very little knowledge on electrical engineering. Please be patient with my questions.
We need to power a 12V6A peltier device to show the cool down process. We already have the heat sink and peltier theory in place, so this question is more related to the circuit handling the peltier.
1st Test: We performed a simple test using a 6V battery pack (4 AA's) using a breadboard. We applied the lowest resistor we have of 10 ohms (to get as much from the battery pack and still control the current), in an arrangement + >> R10 >> Pelt >> -.
Results: The peltier worked at some extent, but the resistor got really hot and started burning up.
Q1.1?? Why does a small 10 ohms resistor get really hot (to the point of smelling and turning black) when supplying just 6V (4 AA's pack)?
Q1.2?? Does it make a difference to put the resistor closer to the source or closer to the ground? Our thought now is if we put the resistor close to the ground, it will handle less heat because the current is passing through the peltier first and thus the peltier consuming it. If we put it before the peliter, all the current passes through the resistor first, heating up.
We are going to upgrade the source to a rechargeable 14.4V 6A (that's what we have at our disposal), so we can hopefully run the test for 1 hour.
Using what we learned from ohms law, we need to drop the current from 14.4V to 12V, and limit the amps to 5, so we need a resistor of 0.48 (0.48r = (14.4v - 12v) / 5i).
Q2.1?? What kind of resistor do I need to get this right without burning the resistor?
Q2.2?? With such small resistance, does it even make sense to put a resistor? Should we just connect the peltier directly to the battery source and assume it can handle the extra voltage and current?
Thanks in advance for the help.