DEFINITION microfarad Posted by: Margaret Rouse WhatIs.com Contributor(s): Kenda, Jack Clements The microfarad (symbolized µF) is a unit of capacitance, equivalent to 0.000001 (10 to the -6th power) farad. The microfarad is a moderate unit of capacitance. In utility alternating-current (AC) and audio-frequency (AF) circuits, capacitors with values on the order of 1 µF or more are common. At radio frequencies (RF), a smaller unit, the picofarad (pF), is often used. This unit is equal to .000000000001 (10^-12) µF. In RF scenarios, capacitances range from about 1 pF to 1,000 pF in tuned circuits, and from about 0.001 µF to 0.1 µF for blocking and bypassing. At audio frequencies (AF), capacitances range from about 0.1 µF to 100 µF. In power-supply filters, capacitances can be as high as 10,000 µF. Capacitor, 1/3 M.F.D. (microfarad) within wooden insulating box. Two terminal posts set in an insulating box. Maker's name and place 1/3 M.F.D No. 34402scientific instrument, capacitor, electrical engineering, laboratory

In 1993 this items was held in the Mt Helen Physics Department Optic Laboratory.Wattmeter type PWG, Range 0-1.5 kw, semi-circular scale. Three volt ranges: 150v, 300v, 600v. 50 Hz. In varnished wooden carry case, with hinged lid and leather carry strao. Calibration chart inside lid. Serial Number 2973scientific instrument, wattmeter, electrical engineering, laboratory, electrical instrument, a j william, mount helen campus, physics department, optic laboratory, a.j. william

Used in Physics and Electrical Engineering laboratory experiments.D.C. micro and milliammeter, 6 ranges: 100 microAmp; 500 microAmp; 1 milliAmp, 5 milliAmp, 10 milliAmp, 50 milliAmp. Semi-circular scale. In varnished wood case with hinged lid. Leather strap carry handle. Series No 5276 Type PC6scientific instrument, ammeter, electrical instrument, physics, electrical engineering, laboratory

Acoustic siren operated by compressed air. Incomplete.Brass siren operated by compressed air, without matching base connector. Numbers 8, 10, 12 are on the 'spring screws' below the perforated platescientific instrument, siren, physics, sound, compressed air

A glass prism of equilateral triangular shape mounted by a ball-joint to a vertical brass stand and brass base. scientific instrument, prism, optics

Four sound boxes (or resonators) made of thin varnished wood panelling.scientific instrument, resonators, sound boxes

These organ pipes were used for Physics experiments at the Ballarat School of Mines. Seven timber organ pipesscientific instrument, ballarat school of mines, organ pipes

These organ pipes were used for Physics experiments at the Ballarat School of Mines. A series of brass blocks connectable with insertable pint, mounted on black panel on a varnished wood base konwn as a Post Office Box (Sreies Resistors).Serial Number 1941scientific instrument, ballarat school of mines, physics

Most were used in various capacities at Ballarat School of Mines or University of Ballarat.Assorted lamps including Edison Carbon filament light bulbs and other special purpose lamps, .1-3) Robertson, pear shaped 220 V 16, carbon filament? bayonet light bulb with 'nipple'. .4) Ediswan, standard shaped, 928, carbon filament? bayonet light bulb with 'nipple'. .5) (B in a circle) 280 V 32 oo1A, pear shaped, carbon filament? bayonet light bulb with 'nipple'. .6-7) Crompton? standard shaped, carbon filament? bayonet light bulb. Clear glass with an amber tint. .8) 230-240 V 40 W, pear shaped, wire filament bayonet light bulb. .9-10) Osram standard shaped, heavy spiral and disc electrodes, bayonet light bulb. (The disc is loose in 10) .11 a&b) Osram black glass, large standard shaped, 230-240 V 125 W, bayonet light bulb. .12) Philips tubular shaped projector lamp with instruction leaflet. .13) Philips tubular shaped projector lamp with instruction leaflet in original box. .14) EH JA 12 V 55 W small projector lamp. .15) Large special purpose, standard shaped, frosted bayonet light bulb. .16) Siemens, standard shaped, modern Edison screw light bulb. .17) Philips, standard shaped, modern Edison screw, frosted light bulb. .18) Crompton, gas filled 240 V 75 W, standard shaped, bayonet frosted light bulb in original box. .19) Crompton, gas filled 230 V 300 W. standard shaped, large modern Edison screw light bulb. .20) Probably an extension cord with a bayonet fitting at one end connected by a twisted cord of two fabric covered wires to a large socket. This socket has a copper Edison screw inner, surrounded by a ceramic tube and covered with a copper housing. The housing is cracked in two places.Some have makers brand and voltage and wattage stamped onto the glass.scientific instrument, ballarat school of mines, globes, edison, lamps, light bulbs, bayonet

The test rig is contained in a metal frame with sloping front panel that contains the indicator and number seting knobs. A pespex lift-up lid coves numerous valve sockets and a set of coding wheels. Both sides and back covered with pespex. Metal surfaces panted hammerton grey. abbreviated working instructions and AVO Valve data manual.Serial Number 1961scientific instrument, ballarat school of mines, valve characteristic meter

Milliammeter in wooden case, with leather range 100-500ma. Semi-circular scale with mirror-backed pointer.Model 155m Serial Number 38783scientific instrument, ballarat school of mines

A.C. Voltmeter, 150-600 volts non liner, semicircular scale ventilation holes. One termnal post on each side panel. Maker's name plate on top face below scale windo. Adjacent: spring-loaded contact button. Model 155. Serial Number 42339scientific instrument, ballarat school of mines, weston electrical instrument co

Used in Electrical Engineering and experimental set-ups in the laboratories,Voltmeter with the range 180-320 volts.scientific instrument, ballarat school of mines, voltmeter, electrical engineering, experiments

Any early acquisition y the Mount Helen Physics Department. Oscilloscope user assembled supplied by Dystrom Limited, Gloucestor, England, under the Heathkit brand. Grey ripple finish sheetmetal case, with ventilation slots. Leather strap carry handle. Specifications not attached. scientific instrument, ballarat school of mines, bill durant, physics

A spherical glass vessel with two principles electrodes mounted inside opposing cylindrical extensions. A third mounted in an offset extension. A fourth electrical connection in a branched extension, perpendicular to main axis. scientific instrument, x-ray tube, xray, physics

A glass cylindar with a spherical enlargement in the middle part, with metal end attachments. ONe end connections for emitter filament heating current. Other end - attachmentes for electron target, with some provisin for air/gas flow. Paper label on one end, tabular voltages, currents, etc. Serial Number 243738scientific instrument, electron valve, x-ray

Probably acquired for use in Telegraphy courses run at the Ballarat SChool of Mines between 1875 and 1893. Telegraph relays amplified electrical signals in a telegraph line. Telegraph messages traveled as a series of electrical pulses through a wire from a transmitter to a receiver. Short pulses made a dot, slightly longer pulses a dash. The pulses faded in strength as they traveled through the wire, to the point where the incoming signal was too weak to directly operate a receiving sounder or register. A relay detected a weak signal and used a battery to strengthen the signal so that the receiver would operate. This relay was made by the firm of Charles T. and John N. Chester, two brothers who successfully partnered in New York City. Charles (1826-1880) founded the firm and provided the expert telegraphy knowledge while John (1820-1871) kept the books and managed the business operations.(http://americanhistory.si.edu/collections/search/object/nmah_706518, accessed 25/01/2018)Electromagnetic relay device used in telegraphy. The working parts mounted on a brass plate, attached to a wood base. Equipped with four terminal posts. Adjustable contactor mechanism. This electromagnetic Relay Device was used in Telegraphy at the Ballarat School of Mines. After a special meeting of the Ballarat SChool of Mines Council in 1874, a decision was made to offer instruction in Telegraphy, a subject not directly related to mining. Telegraphy was taught by W.P. Bechervaise, postmaster at Ballarat. On 07 October 1874 the Ballarat Courier correspondent reprted on Telegraphic training: "... these classes ... are a snare and a delusion, as there is scarcely the remotest chance of obtaining employment when the examination has been passed."scientific instrument, telegraph relayer, telegraphy relay device, telegraphy

Eight various valves. .1) Matchlett Rectifying Valve Type ML-IE, 11.7 AMP@10v, oil immersion .2) Mullard TY2-125, Serial Number 4878./3 26UJ 5U4GB Miniwatt 980 .4) Electonic Comany New Jersey ELCGH-1/5 Collidge Tube, G.E./GMINNIWATT955 6x5GTscientific instrument, valves, mullard, rectyfying valve, electrons co, eimac, general electic, lamp, machlett laboratories inc., miniwatt

This item was used at the Ballarat School of Mines during Physics lectures. Wave demonstration apparatus in a wooden frame for benchtop use. scientific instrument, wave demonstraton apparatus, ballarat school of mines, h.b. silberberg & co.

Two pan balance.scientific instrument, balance

A fluorescent screen seen with an illuminated scale shows the wavelength(s) of entering light. A Cylindrical Quartz Lens is provided to concentrate on the slit light from weak sources. The scale is illuminated by regular white light through a window. Ultra Violet Spectroscope. A black finished device with adjustable aperture in a storage box with eyepiece shield and clamping screw. scientific instrument, balance, spectoscope, ultra violet spectroscope, prism

Magnetometer set in a black storage box with hinged lid. Inside is lined with blue flet, wirh moulded recessed for all parts. The magnetometer incorporatethermomtetr and viewing windows for observing interally mounted mirror. Included also 3 pages of instructions in French. scientific instrument, magnetometer, andersson and sorensen

Dip circle apparatus contained in a glass-sided vertical wood cabinet, which can be rotated around a vertical axis through 360 degrees. Fully graduated circular scales and levelling screws in the base. Instructions for use available. scientific instrument, dip circle apparatus

Made specially for H.B. Silberberg & Co.Post Office Box (3 arms of Wheatstone Bridge) in a wooden case used at the Ballarat School of Mines. scientific instruments, h.b. silberberg & co., philip harris, post office box

450 OHM Galvanometer. Black metal case with levelling feet. Clamps and zero adjustment on top. Two terminal posts.scientific instruments, galvonometer, cambridge instrument co. ltd

Item looks to have been adapted for bench top use Sindanyo high temperature insulation boards are manufactured from cement based products, reinforced with selected fibres. They have been specifically designed to provide excellent service under demanding thermal and electrical applications. Sindanyo is a non-asbestos, non-combustible product that is easily machined. This insulation board is a popular option when a high quality, strong and rigid material is required.400/500 Volt, 5 amp, 50 Hz 3-phase balanced load. Circular scale with lead and lag markings and graduations. The 22cm diameter meter rear-mounted to black sindanyo board, supported by wood brackets on wood base. Five terminal posts on panel below meter. Wire connections at rear. No maker's name Patent Number: 162471/20 Serial Number 263475scientific instruments, power factor maker, lead and lag markings, terminal posts, power factor meter, wire connections, sindanyo board, non-combustible, insulation, electrical applications

Gunsight in a wooden storage Box. An arrangement of lens contained in a 6cm diameter x 70 cm long steel tube. Contained in a polished wood box with a hinged lid. Box also holds several accessories - aperture, resisters, filters. Serial Number 173scientific instruments, gunsight, lenses

Potentiometer Volt Box, 6 ranges: 1.5, 15, 30, 150. Black terminal panel on top of polished wood box. Large circular ventilation holes in all six sides. Distributed by A.E. Supplies Pty Ltd., Melbourne. scientific instruments, potentiometer volt box, cambridge instrument co. ltd, volt box

Theodolite with internal focussing. One plate bubble level. Three levelling screws. Engraved. "Crosshair" and stodia lines. Aladide levelling bubble with top mirror. Fully rotatable telescope with gunsight. Fits tripod Catalogue Number 4107.scientific instruments, theodolite, e.r. watts & son ltd

Gas filled tube with bronze colour coating. O. Lodge Patent E866scientific instruments, discharge tube