Why Do Electronics Fail?

Your HVAC system has countless little controller boards and electrical components driving it. There’s the boards in your thermostat, furnace, and in some cases even in your pumps, just to scratch the surface. These boards do all burn out eventually, but the weird thing is that, there are no moving parts in them TO burn out. What’s going on?   Anatomy of a Circuit Board Let’s take apart one of these circuit boards and see what’s going on. The backbone of this whole thing is the PCB, Printed Circuit Board. This is that flat chunk of plastic that everything else sits on. It’s the thing you normally hold in your hands. These boards are basically copper and plastic, that act as wires, connecting multiple parts together. There’s traces of copper on the board that go from one item to the next to the next. PCB’s are pretty long-lived, but they have their weaknesses: chemicals, voltage, and physical stresses. If there’s too much power going through one part of the board, such as from a power surge, it can blow out one of the traces. If there’s anything at all corrosive that leaks onto the board, it’ll eat the traces or even eat a component of the board itself. Sometimes, this even happens from components on the board themselves, capacitors and batteries can leak corrosive fluids that will cause complete failures. In retro electronics, it’s actually pretty common to “re-cap” a […]

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What is a PLC?

Automated systems all need something to come back to. There needs to be some sort of brain that runs the infrastructure, does all the math, and calls the shots within the building. This needs to be a programmable device, that works on numerous inputs and outputs, to control what’s going on. It needs to be rugged, reliable, and easy to use. We call it a PLC, Programmable Logic Controller.   The Basic Problem When we fully automate a building, chemical plant, or manufacturing center, we instantly open ourselves up to hundreds of thousands of little things that need to all be overseen, adjusted, and managed in a rational way. We don’t want a person to be opening or closing a vent by hand, or to have workers walking out to manage mixing valves, or anything else by hand. Everywhere a person might do something, we need a computer, sensors, and actual controls to drive. We could use a standard desktop computer, that has the raw processing power to handle a couple million inputs and outputs, but it sucks up a ton of power, it doesn’t have that many physical IO connections, it can’t survive being dropped or beaten around, it’s too big, and it’s not guaranteed to be easy to configure. In fact, it’s probably guaranteed to be a nightmare to configure at install and every repair session. The final nail in the coffin comes in terms of security. Common […]

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How Far Does Automation Go?

Your fire safety system is basically a parasite with its tendrils all over the building. It can tap into breakers, elevators, hvac, security, and more inside the building, but is that as far as Building Automation goes? How much can we automate inside a building, if we throw our budget out the window and just build until our engineers are completely fried? Environmental Automation Let’s start with human-level, the things operating a building around us, that we’ll never see or realize are there, managing the environment in the background. We all know that our HVAC systems turn off and on in response to temperature. That is pretty much just the tip of the iceberg. With modern controls we can regulate the air temperature, pressure, humidity, and in some sense, even the ‘freshness’ of the air. We can create rooms with positive pressure, such as surgical words, to prevent bacteria from getting in. We can create negative pressure to help air circulate or pull in fresh outside air. There’s humidifiers, dehumidifiers, and operating schedules to ensure a given volume of air travels into or out of a room on a schedule. There’s even occupancy sensors to concentrate the most environmental management effort where it matters: around people. Then things go a step farther. There are occupancy sensors managing the lights, but with modern LED systems, some buildings actually change the intensity and color of the lights throughout the day, on top […]

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