Test & Measurement Education

This session provides a Quick introduction to Electrical Power Systems, Electrical Fundamentals, the need for Protection in Power Systems and Challenges for Protection. 

This presentation help designers compensate the flyback isolated topology with load transient requirements.An innovative and versatile solution is presented.

PARTS AND MATERIALS Operational amplifier, model TL082 recommended (Radio Shack catalog # 276-1715) Operational amplifier, model LM1458 recommended (Radio Shack catalog # 276-038) Four 6 volt batteries One meter movement, 1 mA full-scale deflection (Radio Shack catalog #22-410) 15 kΩ precision resistor Four 1 MΩ resistors The 1 mA meter movement sold by Radio Shack is advertised as a 0-15 VDC meter but is actually a 1 mA movement sold with a 15 kΩ +/- 1% tolerance multiplier resistor. If

Seeing as how a common meter movement can be made to function as a voltmeter, ammeter, or ohmmeter simply by connecting it to different external resistor networks, it should make sense that a multi-purpose meter (“multimeter”) could be designed in one unit with the appropriate switch(es) and resistors. For general purpose electronics work, the multimeter reigns supreme as the instrument of choice. No other device is able to do

What would happen to this meter movement, if connected directly to a 6-volt battery?

Most ohmmeters of the design shown in the previous section utilize a battery of relatively low voltage, usually nine volts or less. This is perfectly adequate for measuring resistances under several mega-ohms (MΩ), but when extremely high resistances need to be measured, a 9 volt battery is insufficient for generating enough current to actuate an electromechanical meter movement. Also, as discussed in an earlier chapter, resistance is not always a stable

PARTS AND MATERIALS Two 6 volt batteries One potentiometer, single turn, 10 kΩ, linear taper (Radio Shack catalog # 271-1715) Two high-value resistors (at least 1 MΩ each) Sensitive voltage detector (from the previous experiment) Analog voltmeter (from the previous experiment) The potentiometer value is not critical: anything from 1 kΩ to 100 kΩ is acceptable. If you have built the “precision potentiometer” described earlier in this chapter, it is recommended that you use it in

So far we know that AC voltage alternates in polarity and AC current alternates in direction. We also know that AC can alternate in a variety of different ways, and by tracing the alternation over time we can plot it as a “waveform.” We can measure the rate of alternation by measuring the time it takes for a wave to evolve before it repeats itself (the “period”), and express this

Let’s start with a series circuit consisting of three resistors and a single battery: The first principle to understand about series circuits is that the amount of current is the same through any component in the circuit. This is because there is only one path for electrons to flow in a series circuit, and because free electrons flow through conductors like marbles in a tube, the rate of flow

Show how this ammeter would be connected to the light bulb circuit to measure the circuit’s electric current: Also, draw a schematic diagram of this same circuit (with the ammeter connected).

PARTS AND MATERIALS 6-volt battery 6-volt incandescent lamp Basic circuit construction components such as breadboard, terminal strip, and jumper wires are also assumed to be available from now on, leaving only components and materials unique to the project listed under “Parts and Materials.” CROSS-REFERENCES Lessons In Electric Circuits, Volume 1, chapter 1: “Basic Concepts of Electricity” Lessons In Electric Circuits, Volume 1, chapter 8: “DC Metering Circuits” LEARNING OBJECTIVES How to measure current with

A meter is any device built to accurately detect and display an electrical quantity in a form readable by a human being. Usually this “readable form” is visual: motion of a pointer on a scale, a series of lights arranged to form a “bargraph,” or some sort of display composed of numerical figures. In the analysis and testing of circuits, there are meters designed to accurately measure the basic quantities

In the course of learning about electricity, you will want to construct your own circuits using resistors and batteries. Some options are available in this matter of circuit assembly, some easier than others. In this section, I will explore a couple of fabrication techniques that will not only help you build the circuits shown in this chapter, but also more advanced circuits. If all we wish to construct is a

An oscilloscope is a very useful piece of electronic test equipment. Most everyone has seen an oscilloscope in use, in the form of a heart-rate monitor (electrocardiogram, or EKG) of the type seen in doctor’s offices and hospitals. When monitoring heart beats, what do the two axes (horizontal and vertical) of the oscilloscope screen represent? In general electronics use, when measuring AC voltage signals, what do the two axes

Volume I chapter 1.1 discusses static electricity, and how it is created. This has a lot more significance than might be first assumed, as control of static electricity plays a large part in modern electronics and other professions. An ElectroStatic Discharge event is when a static charge is bled off in an uncontrolled fashion and will be referred to as ESD hereafter. ESD comes in many forms, it can be as

PARTS AND MATERIALS Calculator (or pencil and paper for doing arithmetic) 6-volt battery Assortment of resistors between 1 KΩ and 100 kΩ in value I’m purposely restricting the resistance values between 1 kΩ and 100 kΩ for the sake of obtaining accurate voltage and current readings with your meter. With very low resistance values, the internal resistance of the ammeter has a significant impact on measurement accuracy. Very high resistance values can cause

Suppose I were about to measure an unknown voltage with a manual-range voltmeter. This particular voltmeter has several different voltage measurement ranges to choose from: 500 volts 250 volts 100 volts 50 volts 25 volts 10 volts 5 volts What range would be best to begin with, when first measuring this unknown voltage with the meter? Explain your answer.

A very useful tool for observing rotating objects is a strobe light. Basically, a strobe light is nothing more than a very bright flash bulb connected to an electronic pulse generating circuit. The flash bulb periodically emits a bright, brief pulse of light according to the frequency set by the pulse circuit. By setting the period of a strobe light to the period of a rotating object (so the bulb

It used to be with large AC power systems that “power quality” was an unheard-of concept, aside from power factor. Almost all loads were of the “linear” variety, meaning that they did not distort the shape of the voltage sine wave, or cause non-sinusoidal currents to flow in the circuit. This is not true anymore. Loads controlled by “nonlinear” electronic components are becoming more prevalent in both home and industry,

PARTS AND MATERIALS Multimeter, digital or analog Assorted resistors (Radio Shack catalog # 271-312 is a 500-piece assortment) Rectifying diode (1N4001 or equivalent; Radio Shack catalog # 276-1101) Cadmium Sulphide photocell (Radio Shack catalog # 276-1657) Breadboard (Radio Shack catalog # 276-174 or equivalent) Jumper wires Paper Pencil Glass of water Table salt This experiment describes how to measure the electrical resistance of several objects. You need not possess all items listed above in

A chandelier has five light bulbs in it, and one of them is not working. The problem could be in the chandelier’s wiring (open wire connection, open connection in socket), or in the bulb itself (burned-out filament). Describe a procedure for determining the location of the problem (chandelier vs. bulb), without using any electrical test instruments.

What will this voltmeter register when connected to a battery as shown (assume a battery voltage of 6 volts)? Explain your answer.