Mike's Project Tracker

Managed to get it down to three vias and the routing is a bit better.

Here is an image of my solenoid driver board.  It is 99% autorouted but I did make the traces for the positive inputs for the solenoids much larger for the 10 amps peak they might see.  The current is very brief so the traces are probably larger than they need to be.  The traces for the solenoid inputs are 100 mils, the rest at 16 mils and I have the entire top and bottoms of the board as ground.  There are five vias but I do not think I can avoid them.  I also probably need to line the ICs in a way that is more pleasing to the eye and I have to add the silk screen layer to label everything.

Here is my schematic so far for my solenoid driver board.  The PWM control took up too much space to include on the board due to the limitations of EagleCad's freeware.  Each control circuit has two inputs, one for the trigger and one for the PWM power control.  I might add in a way to disable the single pulse generator so that you can just trigger it on or off if there is room on the board.  However, I can only think of a few instances that would require it as most solenoids will burn out if left on too long.  I will post the EagleCad files including the board layout when I am finished.

Now that I have been lazy about working on my pinball machine for a while, I got mad enough to motivate myself to work on it.  The solenoid driver board is being re-hashed, again but in the meantime I am trying to put together a 6-channel audio mixer and stereo amp. Just quickly, to update on the solenoid driver board I've been working on the schematics for it.  I am at least doing a better job of documenting my work.  I will be posting the schematics and my first board layout soon.  Due to the board sized limitation on EagleCad freeware , I can only fit (at least I think I can) the circuitry to drive six solenoids.  I am fine by this.  It makes my solenoid power distribution more modular.  I will likely use three boards for 18 solenoids.  The EagleCad freeware is limited to a board size of 8 x 10 cm.  I could have used KiCad as it is unlimited but from what I have heard it is not as user friendly and everyone has EagleCad which makes sharing much easier.  I think I will try KiC