Hi all,
I need a little help about solving a problem..
I have this circuit
R35 is 1 Ohm and the Voltage reference is connected to a comparator, which is an overcharge detector that will be active when motor exceeds power.
Well, the problem is the peak voltage created by the motor when power is supplied, because at start up for a very short period of time I measured a maximum of 230mA with my tester, than the current decrease rapidly to 70 ~ 80mA with 0.8V output from R35..
I think the current should be higher, because the voltage reference for overcharge detection is about 260mV and when the power is supplied, I have a continuous overcharge detection which make impossible to run the motor correctly.
However I am just testing the circuit with a motor which consumes 70 ~ 80mA, because our professor told us that we will try it with a 12V 25W motor , so, if I have a current peak 3.3 (or more) greater when I turn on power with a small motor like I have now, how much of current peak will I have with a motor like that?
Maybe is obvious that I have to use an RC snubber circuit. I putted one about 1K and 100n but it doesn't work because off course is not well calculated.
Which snubber can I use to solve the problem and to use both motors?
Thank you for your help..
I need a little help about solving a problem..
I have this circuit
R35 is 1 Ohm and the Voltage reference is connected to a comparator, which is an overcharge detector that will be active when motor exceeds power.
Well, the problem is the peak voltage created by the motor when power is supplied, because at start up for a very short period of time I measured a maximum of 230mA with my tester, than the current decrease rapidly to 70 ~ 80mA with 0.8V output from R35..
I think the current should be higher, because the voltage reference for overcharge detection is about 260mV and when the power is supplied, I have a continuous overcharge detection which make impossible to run the motor correctly.
However I am just testing the circuit with a motor which consumes 70 ~ 80mA, because our professor told us that we will try it with a 12V 25W motor , so, if I have a current peak 3.3 (or more) greater when I turn on power with a small motor like I have now, how much of current peak will I have with a motor like that?
Maybe is obvious that I have to use an RC snubber circuit. I putted one about 1K and 100n but it doesn't work because off course is not well calculated.
Which snubber can I use to solve the problem and to use both motors?
Thank you for your help..
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