/diy/ - Do It Yourself

>>1411133
ok so >>1411043 works with DC power. I forgot the switches weren't on the PCB layout hence why I posted the diagram afterwards

>>1410843 conceptually "works" with AC power, but because the solenoids are wired in series off the DPDT, the second solenoid doesn't get enough power to throw. As far as I can tell >>1411027 should work fine with AC power, it's basically the same thing but with the solenoids wired in parallel from both switches.

>thanks to your ac supply, you have two circuits here, not one
no the reason for that is that I'm trying to design this such that you only need to press one of 3 switches to set system to either up/straight/down. There's a DPDT for up/down and a SPDT for straight ahead (all momentary). I'm making this for my nephew and I want it to be as easy to use as possible, i.e.: one button to represent each direction.

>maybe one of the poles of switch(es) could be fed from one of the throws of the other
that's what I'm trying to avoid, I don't want to have it set up so you have to press two buttons to set the direction.

Pic related is what it's to control, there are two solenoids, one for up/straight ahead, one for straight ahead/down. The truth table for this is:
10 10 (up)
10 01 (straight ahead)
01 01 (down)

The problem with using just one diode is that because the circuit needs to support reversing the polarity of the solenoids, they need to be isolated from each other. It might be possible to do it with relays using AC as well, but diodes are a tenth the price (although admittedly they don't make the cool clicking sound that relays do).

>>1400253
Anything (within reason) but I'd prefer to avoid using a micro-controller. To add a bit more context, what I'm trying to build is a controller for a three-way point (see pic).

I had initially been thinking of using an arduino (I have a D1 mini) but there are a couple of problems with this, firstly if a train arrives from any of the three branches on the right, it can push past the point, putting the into an inconsistent state (and this is for my nephew, so an inconsistent state is inevitable). The the arduino can probably read that change in state but it seems like a bit of a hassle and a waste of my only arduino.

Secondly the arduino can only provide 3.3v and the motors require 12v (AC or DC) so I'd need to use two power adapters and/or complicate the circuit further - ideally I want this to be something I can open up and explain to him at some point.