frequency changer

The device was generically referred to as a frequency changer or just mixer.

With the advent of solid state electronics, it has become possible to build completely electronic frequency changers.

Frequency changers are typically used to control the speed of motors, primarily pumps and fans.

(For the operation of ordinary-type motors, a frequency changer would be needed.

Reverse conducting thyristors are often used in frequency changers and inverters.

Frequency changers vary in power-handling capability from a few watts to megawatts.

The machine proved to be a radio frequency changer that could be bought as war-surplus for about $3.50.

In 1949 two motor-generator frequency changer sets were installed so that the plant could provide power to standard 60 Hz networks.

This motor-generator combination can provide a frequency changer function as well as phase conversion, but requires two machines with all their expense and losses.

They were considered durable for their time (even the AC/TP frequency changer, which was normally problematic).

They proposed a static frequency changer which was built at Jericho Park (Bowie, Maryland) and placed on service in the spring of 1992.

They were the first motive power on the Rhaetian Railway to use frequency changer technology together with AC induction motors.

Remnant fragments of older systems may be tied to the standard frequency system via a rotary converter or static inverter frequency changer.

The Nevians being as eager as the Terrestrials to establish communication, Nerado kept the newly devised frequency changer in constant use.

One UK company, Mazda, produced a triode-pentode frequency changer, the AC/TP.

A frequency changer is an electronic device that converts alternating current (AC) of one frequency to alternating current of another frequency.

Today the frequency changer used in applications up to few tens of megawatts consists of two back to back connected IGBT inverters.

The valve complement consisted of a triode-hexode frequency changer, a variable-μ RF pentode IF amplifier and a high slope output pentode.

In 1986, Baltimore Gas and Electric elected to not renew the contract under which it had operated the Benning Power Station frequency changer on behalf of Amtrak.

Aside from the obvious application of converting bulk amounts of power from one distribution standard to another, frequency changers are also used to control the speed and the torque of AC motors.

A 25-50 Hz frequency changer was installed at White Bay in 1939, allowing power generated at the two railway power stations to be fed into the Sydney County Council's 50 Hz grid as required.

Many exceptions existed, generating stations were dedicated to power or light by the choice of frequency, and rotating frequency changers and rotating converters were particularly common to feed electric railway systems from the general lighting and power network.

The oldest continuously operating commercial hydroelectric power plant in the United States, Mechanicville Hydroelectric Plant, still produces electric power at 40 Hz and supplies power to the local 60 Hz transmission system through frequency changers.

Included in this portion of the syllabus are thermionic emissions with their characteristic curves, diodes, triodes and multi-electrode valves; and the use of valves as rectifiers, oscillators, amplifiers, detectors and frequency changers, stabilisation and smoothing.

Rotating-machine frequency changers used to convert between 25 Hz and 60 Hz systems were awkward to design; a 60 Hz machine with 24 poles would turn at the same speed as a 25 Hz machine with 10 poles, making the machines large, slow-speed and expensive.