First: im new here and this is my first question so if you think that I should ask or behave in a different way, feel free to tell me.
The (My) Problem: We run LEDs on a test stand with ~5V,2.3A and have the Problem of brief (~20µs) disconnects between the LED and the power supply. The disconnect is rapid, so that in some cases the supply will not shut down. In case that happens the voltage at the open contacts increases and there is an amp Peak ~>5A at the Moment of reconnection which destroyes the LED.
There should be a n-mos with a high power, low resistance Resistor in a series Connection in a parallel configation to the LED. The Gate Voltage should be taken of a voltage divider (someone mentioned to me that instead of R1 i should use a z-Diode, although they did not provide a reason for that) The increasing voltage should open the mosfet, wich creates a way to reduce the energy in the circuit and there is no peak when the LED is connected to the circuit again.
My aim is to simulate, build and test a prototype. It is not to create a PCB with the circuit yet. Since Im quite a newbie when it comes to simulations in LTSpice and desinging real circuits I have some difficulties to turn my ideas into a running solution.
-I know i need a resistor before the gate of mosfet, but which one?
-Or how to choose a fitting OP?
-Wich Mosfet shall i use here?
-What are the next steps ?
Thank you for reading, i hope to find help here.