Batteries
Early in the history of electrical science, laboratory physicists found that when metals came into contact with certain chemical solutions, voltages appeared between the pieces of metal. These were the first electrochemical cells. More ...
Integrated Circuit Manufacturing Pattern Transfer
The integrated circuit manufacturing photolithographic pattern transfer process requires a variety of physical and chemical processes performed on a semiconductor substrate. More ...
Magnetism
Electric currents and magnetic fields are closely related. Whenever an electric current flows a magnetic field accompanies the current. When a wire is coiled up, the resulting magnetic flux becomes more concentrated. More ...
Electrical Transformers
A transformer is an electrical device that uses the principle of magnetic induction to step voltage up or step down. Inversely it increases or decreases the current available at the different voltages. More ...
Zener Diode
A zener diode is similar to a standard diode allowing current flow in the forward direction except the semiconductor is more heavily doped and this allows it to operate in the reverse-bias break down mode. More ...
Inductive Reactance
The opposition that the coil offers to ac is called inductive reactance. Like resistance, reactance is measured in ohms. Unlike resistance, reactance changes with frequency. And in an Inductor, the Voltage leads the Current by 90 degrees. More ...
Junction Field Effect Transistor (JFET)
A Junction Field Effect Transistor (JFET) consists of a channel and a pn junction. The gate controls the conductance of the channel. A JFET is a voltage controlled device, therefore no current flows into the gate. More ...
How to Calculate Impedance
Impedance is one of the most difficult things the electronics technician student needs to calculate. To calculate impedance, you must know the value of all resistors and the impedance of all inductors and capacitors in the circuit. Then you can calculate impedance using a simple mathematical formula. More ...
Magnetism
Magnetism is the force exerted by magnets when they attract metals or attract and repel each other. More ...
EMI, RFI, EMC, EMS, What's the Difference?
EMI, RFI, EMC, and EMS all refer to different aspects of radio frequency interference which may cause elecronic devices to malfunction. Correcting these problems can be an art and a science. More ...
Use a Resistor to Measure Inductance
Inductance is usually measured by using an LCM multimeter. It can also be mesured using a resistor. With the resistor method, you adjust the frequency of a sine wave until the AC voltage accross the resistor and inductor are equal. Then using a formula to calculate the inductance. More ...
Capacitors
A capacitor is an electronic component that can store electric charge. A capacitor is constructed with two conductive plates separated by an insulator called a dielectric. More ...
Alternating Current
With DC (Direct Current), electric current flows in only one direction. With AC (Alternating Current), current direction reverses periodically. More ...
Inductors in Series and Parallel
Inductances in series add like resistances in series. The total value is the sum of the individual values. Inductances in parallel values add up like the values of resistors in parallel. The reciprocal of total inductance is the sum of reciprocals of all the individual inductances. More ...
