Hi everyone,
I don't do much high power stuff, so please excuse my ignorance.
I am trying to design an inrush circuit for a fractional horsepower dc motor circuit. The circuit is attached along with a simulation waveform.
Basically, I am getting on Channel A the current in amperes RED (not volts) through the resistor, and on channel B is the voltage drop across a power resistor. The resistor is 15 ohms.
Is there some sort of other limitation than average power for a resistor? Clearly, this is a startup routine and does not repeat often, so we can assume the resistor will have time to cool.
How can I find out if this thing is going to blow up, other than building it?
I estimated about 12-15J of energy need to be dissipated. Or, about 180W in 80mS. How can I choose a resistor? Do I have to do the whole volume and specific heat thing to calculate a heat rise?
Steve
I don't do much high power stuff, so please excuse my ignorance.
I am trying to design an inrush circuit for a fractional horsepower dc motor circuit. The circuit is attached along with a simulation waveform.
Basically, I am getting on Channel A the current in amperes RED (not volts) through the resistor, and on channel B is the voltage drop across a power resistor. The resistor is 15 ohms.
Is there some sort of other limitation than average power for a resistor? Clearly, this is a startup routine and does not repeat often, so we can assume the resistor will have time to cool.
How can I find out if this thing is going to blow up, other than building it?
I estimated about 12-15J of energy need to be dissipated. Or, about 180W in 80mS. How can I choose a resistor? Do I have to do the whole volume and specific heat thing to calculate a heat rise?
Steve