Connectors Education

Isolators are one of the key electronic components used in a solar inverter. They enable communication between low-voltage, sensitive control circuitry, such as microcontrollers, and components connected to high voltage, such as power transistors and sense elements. They also provide a safety barrier for human accessible interfaces and connectors. When it comes to power paths in Solar Inverters, we notice three key trends: Higher power string and centralized inverters are moving towards higher bus voltages enabling the system to deliver higher power, while keeping the current levels the same, Reducing transition times in the DC-AC switching stage to minimize the duration that the IGBTs spend in high impedance, Increasing PWM switching frequency in the DC-AC stage to reduce the size and cost of the magnetics in the design (for example the inductive EMI filters)

Early in my explorations of electricity, I came across a length of coaxial cable with the label “50 ohms” printed along its outer sheath. (Figure below) Now, coaxial cable is a two-conductor cable made of a single conductor surrounded by a braided wire jacket, with a plastic insulating material separating the two. As such, the outer (braided) conductor completely surrounds the inner (single wire) conductor, the two conductors insulated from each

An electrical switch is any device used to interrupt the flow of electrons in a circuit. Switches are essentially binary devices: they are either completely on (“closed”) or completely off (“open”). There are many different types of switches, and we will explore some of these types in this chapter. Though it may seem strange to cover this elementary electrical topic at such a late stage in this book series, I

Conductor ampacity rating is a crude assessment of resistance based on the potential for current to create a fire hazard. However, we may come across situations where the voltage drop created by wire resistance in a circuit poses concerns other than fire avoidance. For instance, we may be designing a circuit where voltage across a component is critical, and must not fall below a certain limit. If this is the

The atoms in insulating materials have very tightly-bound electrons, resisting free electron flow very well. However, insulators cannot resist indefinite amounts of voltage. With enough voltage applied, any insulating material will eventually succumb to the electrical “pressure” and electron flow will occur. However, unlike the situation with conductors where current is in a linear proportion to applied voltage (given a fixed resistance), current through an insulator is quite nonlinear: for

So far, we’ve been analyzing single-battery, single-resistor circuits with no regard for the connecting wires between the components, so long as a complete circuit is formed. Does the wire length or circuit “shape” matter to our calculations? Let’s look at a couple of circuit configurations and find out: When we draw wires connecting points in a circuit, we usually assume those wires have negligible resistance. As such, they

The associative property In addition and multiplication, terms may be arbitrarily associated with each other through the use of parentheses: The commutative property In addition and multiplication, terms may be arbitrarily interchanged, or commutated: The distributive property

With BogusBus, our signals were very simple and straightforward: each signal wire (1 through 5) carried a single bit of digital data, 0 Volts representing “off” and 24 Volts DC representing “on.” Because all the bits arrived at their destination simultaneously, we would call BogusBus a parallel network technology. If we were to improve the performance of BogusBus by adding binary encoding (to the transmitter end) and decoding (to the receiver end), so that

A practical application of switch and relay logic is in control systems where several process conditions have to be met before a piece of equipment is allowed to start. A good example of this is burner control for large combustion furnaces. In order for the burners in a large furnace to be started safely, the control system requests “permission” from several process switches, including high and low fuel pressure, air

Instrumentation is a field of study and work centering on measurement and control of physical processes. These physical processes include pressure, temperature, flow rate, and chemical consistency. An instrument is a device that measures and/or acts to control any kind of physical process. Due to the fact that electrical quantities of voltage and current are easy to measure, manipulate, and transmit over long distances, they are widely used to

While Oersted’s surprising discovery of electromagnetism paved the way for more practical applications of electricity, it was Michael Faraday who gave us the key to the practical generation of electricity: electromagnetic induction. Faraday discovered that a voltage would be generated across a length of wire if that wire was exposed to a perpendicular magnetic field flux of changing intensity. An easy way to create a magnetic field of changing

The Law of Sines (for any triangle) The Law of Cosines (for any triangle)

Wiring for AC and DC power distribution branch circuits are color coded for identification of individual wires. In some jurisdictions all wire colors are specified in legal documents. In other jurisdictions, only a few conductor colors are so codified. In that case, local custom dictates the “optional” wire colors. IEC, AC: Most of Europe abides by IEC (International Electrotechnical Commission) wiring color codes for AC branch circuits. These are listed

By now you should be well aware of the correlation between electrical conductivity and certain types of materials. Those materials allowing for easy passage of free electrons are called conductors, while those materials impeding the passage of free electrons are called insulators. Unfortunately, the scientific theories explaining why certain materials conduct and others don’t are quite complex, rooted in quantum mechanical explanations in how electrons are arranged around the

Aside from the ability to easily convert between different levels of voltage and current in AC and DC circuits, transformers also provide an extremely useful feature called isolation, which is the ability to couple one circuit to another without the use of direct wire connections. We can demonstrate an application of this effect with another SPICE simulation: this time showing “ground” connections for the two circuits, imposing a high DC

The circuit in the previous section is not a very practical one. In fact, it can be quite dangerous to build (directly connecting the poles of a voltage source together with a single piece of wire). The reason it is dangerous is because the magnitude of electric current may be very large in such a short circuit, and the release of energy very dramatic (usually in the form of heat).

PARTS AND MATERIALS 6 volt battery Potentiometer, single turn, 5 kΩ, linear taper (Radio Shack catalog # 271-1714) Small “hobby” motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent) For this experiment, you will need a relatively low-value potentiometer, certainly not more than 5 kΩ. CROSS-REFERENCES Lessons In Electric Circuits, Volume 1, chapter 2: “Ohm’s Law” LEARNING OBJECTIVES Rheostat use Wiring a potentiometer as a rheostat Simple motor speed control Use of voltmeter over ammeter

Perhaps the most challenging aspect of interpreting ladder diagrams, for people more familiar with electronic schematic diagrams, is how electromechanical relays are represented. Compare these two equivalent diagrams: First, the ladder diagram: Next, the schematic diagram: Based on your observations of these two diagrams, explain how electromechanical relays are represented differently between ladder and schematic diagrams.

The terms simultaneous equations and systems of equations refer to conditions where two or more unknown variables are related to each other through an equal number of equations. Consider the following example: For this set of equations, there is but a single combination of values for x and y that will satisfy both. Either equation, considered separately, has an infinitude of valid (x,y) solutions, but together there is only

It should be common-sense knowledge that liquids flow through large-diameter pipes easier than they do through small-diameter pipes (if you would like a practical illustration, try drinking a liquid through straws of different diameters). The same general principle holds for the flow of electrons through conductors: the broader the cross-sectional area (thickness) of the conductor, the more room for electrons to flow, and consequently, the easier it is for flow

This tool is designed to calculate the inductance of two parallel wires