How do I make an integrator to always output LOW and output HIGH only when needed?

Question

The circuit is a constant current source:

^{simulate this circuit – Schematic created using CircuitLab}

When SW1 is open and no load is connected output of integrator is clipped to positive rail, this forces the op amp to swing its output all the way from positive rail to negative rail when a load is connected. obviously it makes sparks and overshoot on the RL which I'm trying to avoid (no matter how fast is the op amp slew rate).

To solve the issue I added a comparator to raise the inverting input of OA1 above the set voltage V1:

^{simulate this circuit}

Even though it does work in a crude simulator, but because I'm not an EE I believe there's a better way to this without an op amp or maybe an improvement is needed to the current circuit that I don't see it!

• How do I avoid sparks at RL and make the load to turn on slowly?

Answer 1

The simplest solution to prevent current overshoot when connecting the load is to disconnect the load by short circuiting it instead of opening the circuit.