Just hearing the words “solenoid” and “relay” may conjure up visions of an ancient electromechanical word, now largely replaced by all-electronic devices, smart motors, and more. That almost makes sense, as these two components in various forms have been with us for over 150 years. But don’t be fooled: both are still vital devices, and […]
FAQ
How to make floating point measurements that count
Sometimes you need to make a “floating” measurement of a current or voltage. By “floating” I mean that you want to measure a voltage across something (or current through something) where neither end of the voltage are ground (0V). While one input being referenced to a supply rail other than 0V isn’t strictly speaking “floating,” […]
Fuses for power protection, Part 2
Part 1 of this FAQ explained fuse basics. Although fuses are simple in principle, selecting the most suitable fuse for the application is more complicated than it may seem at first. Q: What are the key questions to ask when selecting a fuse? A: These are just a few of the considerations: What is the […]
Fuses for power protection, Part 1
Fuses are the oldest and easiest-to-understand circuit-protection components, with several common schematic representations, Figure 1. The function of the fuse is simple and clear: in the case of an overcurrent condition, the fuse “opens” (or blows, in common parlance) which thus stops the flow of current. Despite their simplicity, fuses have subtleties and considerations which […]
Six considerations for better circuit protection
In an electronic system where the power source can be connected the wrong way round, protection should be considered to prevent damage to the circuitry. Most electronic circuits don’t like the power supply being reversed. However, there are other eventualities you could protect your circuit or system from temperature, humidity, excess current or excess loading, […]
Basics of ground fault interrupters
Ground-fault circuit interrupters (GFCIs) are sometimes also called earth leakage or residual-current circuit breakers. They can sense leakage current to earth ground and interrupt the circuit automatically when leakage current exceeds a predetermined value. A typical way of detecting ground fault currents is through the use of a core-balance protection device. Here hot (sometimes called […]
Choosing a reference voltage for an ADC
Analog-to-digital converters (ADCs) need a reference voltage (VREF) input in order to operate properly. ADCs convert analog inputs that can vary from zero volts on up to a maximum voltage level that is called the reference voltage. The reference voltage determines the ceiling of what the ADC can convert, and is essentially the yardstick against […]
Difference between a brushless dc motor and a shaded pole induction motor
Motors that power cooling fans tend to be either brushless motors or induction motors. Here we examine the key differences in the construction of these two motor types and explain the reason for the striking differences in energy efficiency between the two types. Brushless motors are sometimes called electronically commutated motors. Here commutation refers to […]
Learning SMPS the hard way
By Syed Tahmid Mahbub, EDAboard.com forum member SMPS is the toughest section in power electronics. For this subject, you require additional knowledge for choosing the active and passive parts used in SMPS circuits. The special type of parts often required in power electronics (i.e. for low-frequency applications) may not be suitable in the case of […]
Choosing a reference voltage for an ADC
Analog-to-digital converters (ADCs) need a reference voltage (VREF) input in order to operate properly. ADCs convert analog inputs that can vary from zero volts on up to a maximum voltage level that is called the reference voltage. The reference voltage determines the ceiling of what the ADC can convert, and is essentially the yardstick against […]
