Hi all,
I am working with a coil made of 14AWG wire.
There are approximately 60-70 windings that are 12" in diameter.
The resistance of the coil is 0.6 OHMS.
I am using 12 Volts DC @ 5A power supply.
I have put a 10 OHM 50 W resistor in series with the power supply and coil windings.
My problem is that the resistor is generating an awful lot of heat if I leave the current on for too long.
I have added aluminum heat sinks that seem to help a little, but still the resistor gets up to 190 degrees F when I leave the current on for long times, say 10 minutes.
Is there another way to keep the current constant to say, 1A, without using a resistor?
My goal is to create a steady DC magnetic field so I prefer a simple circuit without using high frequency switching, if that makes sense i.e. to use only DC, not pulsed, if possible.
As an aside, I don't understand how the 12V 5A DC power supply can stay so cool, even if I draw 4A from it.
I presume because it is a switching power supply?
It is like a laptop or LED lights style power supply, as in the image below, just FYI...
Thanks in advance for any ideas!
I am working with a coil made of 14AWG wire.
There are approximately 60-70 windings that are 12" in diameter.
The resistance of the coil is 0.6 OHMS.
I am using 12 Volts DC @ 5A power supply.
I have put a 10 OHM 50 W resistor in series with the power supply and coil windings.
My problem is that the resistor is generating an awful lot of heat if I leave the current on for too long.
I have added aluminum heat sinks that seem to help a little, but still the resistor gets up to 190 degrees F when I leave the current on for long times, say 10 minutes.
Is there another way to keep the current constant to say, 1A, without using a resistor?
My goal is to create a steady DC magnetic field so I prefer a simple circuit without using high frequency switching, if that makes sense i.e. to use only DC, not pulsed, if possible.
As an aside, I don't understand how the 12V 5A DC power supply can stay so cool, even if I draw 4A from it.
I presume because it is a switching power supply?
It is like a laptop or LED lights style power supply, as in the image below, just FYI...
Thanks in advance for any ideas!