Electrical4U 
Earlier pages covered the usual gates in digital electronics: the basic AND gate, OR gate and NOT gates, plus NAND, NOR, XOR and XNOR. An INHIBIT gate adds a control pin that can freeze the output. Designers use that pin when a path must stay quiet unless a separate enable is true.The inhibit pin, when … Read more
What is an Alternator? An alternator is defined as a machine which converts mechanical energy to electrical energy in the form of alternating current (at a specific voltage and frequency). Alternators are also known as synchronous generators. Where is an Alternator Used? An automotive alternator supplies vehicle loads and charges the battery while the engine … Read more
A transfer function is the Laplace ratio of a linear control system output to its input, taken with all initial conditions at zero. A block diagram draws that ratio as a block. Arrows carry the input and output signals. The reference input (the excitation or cause) passes through that transfer function and becomes the controlled output … Read more
Schering Bridge Theory A Schering Bridge is an AC four-arm network that measures a capacitor’s capacitance and its dissipation factor. The same reading, with known electrode geometry, gives relative permittivity of a dielectric. The Schering Bridge circuit is below.c1 is the unknown capacitance. r1 is its series equivalent loss resistance. c2 is a low-loss standard … Read more
When an unloaded transformer is energised, its primary draws the current needed to establish core flux. In sinusoidal steady state, the ideal flux waveform is 90 electrical degrees from the applied voltage. Flux is the time integral of winding voltage. Its steady-state maximum therefore occurs one-quarter cycle from the voltage maximum. At a voltage zero … Read more
A PC can send a command to a microcontroller, which then drives a relay in a circuit-breaker’s control circuit. The lab board below is a Remote Control Circuit Breaker Using a Microcontroller. A power plant uses dedicated close and trip coils with interlocks. It does not use this GPIO-to-relay example. The demonstration uses these parts: … Read more
Hay, Maxwell and Anderson already cover much inductor work. Hay’s bridge suits quality factor above 10. Maxwell’s bridge suits Q from about 1 to 10. Anderson bridge covers a wide L span. Owens Bridge is the Owen L-C bridge used when you want that wide L span in terms of a standard capacitor, including incremental … Read more
A servo motor is a closed-loop actuator built around a servomechanism. The loop holds shaft angle, and often speed or torque, to a command. An open-loop DC motor is a poor fit for a control-surface position loop such as an aircraft tail. The pages below cover common places that closed-loop motor shows up. Servo Motor in … Read more
What is Maxwell Bridge A Maxwell Inductance Capacitance Bridge is a four-arm AC Wheatstone bridge used to measure self-inductance by a null. The unknown coil sits in one arm. A parallel resistor and capacitor in the opposite arm make the Maxwell-Wien form. The inductive arm has a lagging phase. The capacitive arm has a leading … Read more
Anderson’s Bridge Anderson’s bridge is the low-Q inductance bridge. Maxwell bridge covers medium Q. Hay’s bridge covers high Q. Maxwell and Hay both struggle to null a low-Q coil. Use Hay for high Q and Maxwell for medium Q. Anderson’s Bridge is a modified Maxwell’s inductance-capacitance bridge with an extra resistor-capacitor path for low Q. … Read more