Hi every one,
I've build the circuit in graph 1 to test the holding and latching current of a BT151 SCR, and found them around 10mA.
then, I wanted to build a latching circuit that has ON/OFF push-buttons (just to clearly understand the SCR) with a DC motor (load) which draws about 40 to 50 mA which is higher than both the holding and latching currents, but the circuit (in graph 2) faced a problem that is the SCR doesn't keep latching while the input signal is not applied, then I tried another motor drawing about 200 mA and everything went well.
before changing the motor I've tried to change the gate resistors to increase the gate trigger current but with no benefit.
my question is that why the latching current differs in both circuits? does the inductive load play a role in changing the value of the Latching current?
Thanks.
I've build the circuit in graph 1 to test the holding and latching current of a BT151 SCR, and found them around 10mA.
then, I wanted to build a latching circuit that has ON/OFF push-buttons (just to clearly understand the SCR) with a DC motor (load) which draws about 40 to 50 mA which is higher than both the holding and latching currents, but the circuit (in graph 2) faced a problem that is the SCR doesn't keep latching while the input signal is not applied, then I tried another motor drawing about 200 mA and everything went well.
before changing the motor I've tried to change the gate resistors to increase the gate trigger current but with no benefit.
my question is that why the latching current differs in both circuits? does the inductive load play a role in changing the value of the Latching current?
Thanks.
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