First of all I’m not electrical engineer. The original idea is described here.
It is a model railroad problem. The rails are carrying a power signal (DCC) 12-18 V. The frequency is ~17 kHz. It is a square wave signal described here.
The circuit swaps the hi and low rails when the short occurs. This it happens at the gap between two insulated parts of the rail track with the hi and low rails not corresponding. When the train wheel bridges the two unmatched rails we have a short. The reverser has to detect this at a lower level of the boosters amper limit and switch the signal to the rails of the reverse section.
In the original circuit, I replaced the shunt with an ACS712 current detector. I replaced the other parts in the circuit with parts that are available in Ltspice to simulate it. The original circuit checks and the second gap. In my scheme is only the detector for one gap.
- Will this circuit work?
- Is the ACS712 sensor a good replacement?
- What are the suitable DIP components?
- Can I "catch" the output from the 555 with an Arduino and switch the relay?
I have and other thoughts like set the comparator's limits with a potentiometer or from Arduino.
I hope the comments in the LTspice schematic will help. Any thoughts and critique are welcome. I didn't find a way to attach the LTspice file.