Hello, I am attempting to build a circuit will basically allow me to vary the input voltage to a low impedence load. I tried using a simple 5Kohm potentiometer, and connected an opamp after to it, so as to be able to drive the low impedence load. The problem however is the power dissipation. The load needs about 0.3A at 24 V. My power supply can source this no problem, however i have about 36 of these loads and would like to control their input voltages individually.
I did some quick math to and found that the op-amp exceeds its junction temperature and shuts off. I am using a TCA0372BDP1G (from digikey) opamp, that is capable of sourcing upto 1A.
I read that adding a pull-up resistor will lower the power dissipation, however my calculations reveal that even with the pull-up, i will still be exceeding the juntion temperature of the opamp.
is there any other circuit that will allow me to use my power supplies current directly without doing through the opamp, but still use the opamp as the voltage source? Any help will be much appreciated.
Thanks.
I did some quick math to and found that the op-amp exceeds its junction temperature and shuts off. I am using a TCA0372BDP1G (from digikey) opamp, that is capable of sourcing upto 1A.
I read that adding a pull-up resistor will lower the power dissipation, however my calculations reveal that even with the pull-up, i will still be exceeding the juntion temperature of the opamp.
is there any other circuit that will allow me to use my power supplies current directly without doing through the opamp, but still use the opamp as the voltage source? Any help will be much appreciated.
Thanks.