Splash-Pod: The Personal Water Park

Step 9 Building the electrical circuit.

First things first: safety.

The area under the tub (inside the 'box') might get a little bit wet from errant spray but it won't be drenched like above (direct splashes) and below the chassis (from the drain). The electronics need to have decent protection against water because it is still possible that a short could occur. The battery is enclosed inside a plastic container and I have a 2 amp fuse on the positive side. If all four solenoids are pressed at the same time, 1.6Amps should be drawn. The only way the fuse should blow is if some other load is introduced, like a ground short. The solenoid valves are in the most direct area for getting stray water, so insulated electrical contacts were used here. All solder joints were sealed up with heat shrink and electric tape and the positive and negative lines were kept far away from each other. All of these precautions were taken to ensure that a short would not occur.

I might have gone overboard with all of that because after 2 hours of leak testing, and random play there was hardly a single drop of water inside the box. Still, better safe than sorry.

Since all of the components run on 12v, the positive lines are run in parallel and share a common ground. The circuit for each button is the same:

(-) Battery (+) -> Fuse -> Breakout bundle ->

Push-button switch -> Solenoid (-) back to battery
Push-button switch -> Solenoid (-) back to battery
Push-button switch -> Solenoid (-) back to battery
Push-button switch -> Solenoid (-) back to battery

It's all very simple. Once the lines are measured out and cut, the connectors can be crimped to the ends and hooked up to the components. Testing is easy enough, press the button and you should hear the solenoid valve open up. Now we know it works.

The battery is good for 7.2 amp hours which means I have enough juice, in a perfect world, to last for about 10 hours. That's if all four buttons were held down, all at the same time, for ten hours straight. That's not going to happen very often. So we should have plenty of power all Summer long.