Volume 1, Issue 2, February 2015 - Page 17

17

Obscure Adventures Magazine

in a few different sizes and

I've had good luck using the Firgelli model you see in the video to the right to control the throttle on my Yamaha kicker engine.

Another aspect of the installation is ensuring a good source for both the positive and negative wiring in the circuits. Your battery is the ultimate source that drives these functions, but connecting every wire directly to the battery can be a nightmare if there is a problem.

To combat wiring issues I use bus bars that give each wire a home connected to the proper positive, or negative, side of the battery.

I cannot over-emphasize the importance of a good ground to the battery. If the ground wires loosen up and make intermittent contact it can really leave you scratching your head. Make sure all connections are tight and over time monitor the connections for corrosion, especially in wet environments. Clean, or replace, corroded connections as needed.

This discussion wouldn't be complete without talking about protecting the whole circuit from unexpected problems like short circuits, or excessive current situations that could damage expensive actuators.

Circuit breakers or fuse blocks

provide cheap insurance against unforeseen electrical issues and should be considered mandatory when setting up a circuit.

Fuse blocks are wired into the circuit and a small glass fuse, or plastic blade style fuse is in-stalled to complete the circuit. The fuse is rated to pass a certain amperage and it it will melt and open the circuit if that amperage is exceeded. This can happen immediately if the circuit is shorting out, or it may happen over time as the fuse weakens.

Circuit breakers serve a similar function, but instead of a dispos-able/replaceable fuse, the breaker can be reset after it trips. Some circuit breakers can automatically reset themselves if the current drops off and the breaker cools down, while others have a button that can be pushed to reset the breaker.

Building a system that incor-porates electical components like relays, switches, actuators, circuit breakers, and fuses requires careful planning.

When wired correctly there are so many functions that can be controlled at the touch of a button and none of this is beyond the realm of the savvy do-it-yourselfer.

There are many websites that explore these concepts in more depth as well as provide calcu-lators for determining proper wire size based on amperage require-ments. Here's a simple one from The Engineering ToolBox.

The video above demonstrates reversing polarity between positive and negative on the battery to spin the actuator's motor in opposite directions. This causes it to extend or retract. All of the switch and relay discussion in this article is ultimately making this to happen

A couple of busbars connected to each terminal of the battery and mounted in a dry, out-of-the-way location allow for easy connections and troubleshooting when multiple circuits are involved

This fuse panel by Blue Sea Systems has a feed lug for 12V positive on the bottom and outputs for up to 12 circuits. The blade style fuses can be found almost anywhere and come in a wide range of amperage ratings.

Above: Circuit breakers come in different varieties and sizes, but they serve to protect components in the circuit by "breaking" the circuit if excessive current or a fault is detected.

Auto-reset breaker

Manual-reset breaker