I'm using the following circuit to regulate voltage running to a fan using PWM as the control method. The PNP is just a placeholder as Multisim doesn't have the transistor I'm actually using.
What I would like to do is prevent the output voltage to the fan (represented by the 6 Ohm resistor) from dropping below say 5v). So effictively I want something to check the output voltage and if it's below the stated minimum it just makes the output 5v, until such a time as the output voltage rises and it allows it to rise.
Is this possible without discrete simple components? I was thinking something like a Comparator to activate a secondary circuit to take over powering of the fan when the output voltage sags with low duty cycle but am unsure where tio begin with that. I'm not even sure what this is called otherwise I'd look into examples of it.
Any ideas? Or some clues to help me find a solution.
Thanks
What I would like to do is prevent the output voltage to the fan (represented by the 6 Ohm resistor) from dropping below say 5v). So effictively I want something to check the output voltage and if it's below the stated minimum it just makes the output 5v, until such a time as the output voltage rises and it allows it to rise.
Is this possible without discrete simple components? I was thinking something like a Comparator to activate a secondary circuit to take over powering of the fan when the output voltage sags with low duty cycle but am unsure where tio begin with that. I'm not even sure what this is called otherwise I'd look into examples of it.
Any ideas? Or some clues to help me find a solution.
Thanks