Vidya Muthukrishnan What is Nominal Voltage? Nominal voltage is a suitable approximate value used to designate or identify a circuit or system. Examples include 120/240 V and 480Y/277 V. The actual operating voltage can vary above or below that designation within the limits set for the system and connected equipment. The word “nominal” means named or designated. … Read more
What is Electromagnetic Interference? Electromagnetic interference (EMI) is unwanted electromagnetic energy that degrades an electrical circuit or equipment function. It requires an emission source, a coupling path and a susceptible receiver. Coupling can occur through conductors, electromagnetic induction, electric fields or radiation. A time-varying electric field and magnetic field can propagate together as an electromagnetic … Read more
What is Conductance? Conductance, or electrical conductance, describes how readily a specified component carries electricity. It is the ratio of current through the component to voltage across it. For a linear DC element, it is the reciprocal of resistance: G = 1/R. Resistance describes the voltage needed per unit of electrical current. Between two terminals, … Read more
What is an Active Filter? An active filter combines resistors and capacitors with one or more powered active circuit components, commonly a transistor or an operational amplifier (op amp). The active device can provide buffering or voltage gain while the circuit shapes the frequency response. The component values, circuit topology and closed-loop gain set the … Read more
What is a PLC? What is a PLC? A programmable logic controller (PLC) is an industrial computer that reads field inputs, runs a stored control program and commands outputs. Manufacturers design PLC hardware for dependable operation within specified limits for temperature, vibration, electrical noise and contamination. PLCs automate machines and processes in settings such as … Read more
What is SCADA? SCADA stands for Supervisory Control and Data Acquisition. The term describes a control system architecture that gathers data from field sites, presents it through human-machine interfaces (HMIs), records events and measurements, manages alarms and sends authorised supervisory commands. SCADA servers communicate with field controllers such as programmable logic controllers (PLCs), remote terminal … Read more
Two historical circuit types of defibrillators are listed below. Early equipment applied alternating current (AC) for a set interval. Later direct-current (DC) designs stored energy in a capacitor and released it as a short pulse. Modern external defibrillators are described by their monophasic or biphasic shock waveform, with biphasic waveforms preferred in current adult resuscitation … Read more
Why is Bio Amplifier Required? Biological amplifiers, also called bio amplifiers or biomedical amplifiers, raise the amplitude of low-level bioelectric signals so those signals can be analysed. Bioelectric signals usually have low amplitude and low frequency. The amplifier outputs are used for further analysis and they appear as ECG, EMG or any bioelectric waveforms. Basic … Read more
Resting potential and action potential are the voltages across an excitable cell membrane. The membrane separates extra-cellular fluid (outside) and intra-cellular fluid (inside). Extra-cellular fluid has more sodium and chloride ions, but fewer potassium ions. Intra-cellular fluid has more potassium ions. Neurons send electrochemical messages as electrical signals. Those charged chemicals are called ions. Sodium … Read more
Non-electrical parameters such as temperature, heart sound and blood pressure are measured from the human body with electronic equipment. Biomedical Transducers are the devices that convert those biological parameters to electrical signals. The process of conversion is transduction. Generally, transducers convert one form of energy into another form of energy.Two common transducer classes are active … Read more