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 […]
FAQ
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 […]
Options for current sensing: part 2
Part 1 of this FAQ discussed the issue of current measurement and four transducers that can measure current. The first two — shunt resistors and Hall-effect devices — can be used for AC or DC currents. We will now look at two other transducers — the Rogowski coil and the current transformer—which can be used […]
Options for current sensing: part 1
The need to sense and measure current at one or more points in a circuit is very common. In situations ranging from microamps going into or out of a battery to DC current from a solar panel to feedback for a power supply controller to tens or hundreds of amps of AC power to a […]
Power factor and Power Factor Correction, Pt 2
Part 1 of this FAQ discussed power factor and the issues associated with power factors which are not unity, and briefly mentioned power factor correction (PFC). This FAQ explores PFC in more detail. Q: What is PFC? A: PFC is an adjustment of a load’s front-end “appearance” so it presents a resistive-like load to the […]
Power factor and Power Factor Correction, Pt 1
In recent years, considerable attention has been focused on power factor (PF) and power factor correction (PFC) in devices ranging from small appliances to larger systems. Concern about PF and PFC is not new: it has been an issue with AC power delivery in industrial and commercial settings for many decades. The big difference is […]
What is leakage current?
Leakage current flows unexpectedly in almost all circuits, even when the power is off. Current leakage is not limited to electronics, computers, or small signal circuits, and can be found in industrial equipment and three-phase wiring installations, too. Some current will always find a path to ground whether it’s through ground-conducting insulation that’s supposed to […]
Not to be forgotten: the simple, bipolar SCRs and TRIACs
Thyristors or silicon controlled rectifiers (SCRs) and TRIACs are simple bipolar devices which probably get forgotten in this high-tech, CMOS, MOSFET, digital world. A thyristor is a PNPN bipolar device, compared to a normal bipolar transistor which will be PNP or NPN. A common way of explaining their operation is to visualize the thyristor as […]
