Electricity Laboratory Instruments

Comprising 1 welding coil of 5 turns on former with insulated handle and short-circuiting pins,1 annular melting trough with insulated handle to show heating by induction,1 jumping ring which is thrown clear when primary current is started and a floating ring which remains freely suspended when primary current is flowing.

A cycle dynamo, with crank handle, is fitted on base with two output terminals which are connected in parallel to a lamp holder with a lamp.

Single dial, compact size, housed in metal box with dial and knob. Connections through 4mm socket terminals. Accuracy ± 2 %.Maximum voltage 250 volts d.c. 10 nF to 100 nF in steps of 10 nF.

With rotary switch and a pair of 4 mm socket terminals. contains twelve standard preferred value non-polarised capacitors from 100 pF to 0.47 μF. Tolerance ±2%. Values are 100 pF, 220 pF, 470 pF, 1nF, 2.2 nF, 4.7 nF, 10 nF, 22 nF, 47 nF, 0.1 μF, 0.22 μF and 0.47 μF.

For use on double ‘C’ core, wound with 1,100 turns of 22 swg copper wire with a resistance of about 6 ohms and inductance of about 15 henries, size 100 x 60 x 55 mm approx.

Outer copper vessel 125 x 75 mm with perforated shelf and terminal, a porous pot 150 x 50 mm and a zinc rod 125 x 12 mm,with support and terminal.

Contains four capacitors of 1μF, 2μF, 2μF, and 5μF linked in parallel, each via an ON/OFF slide switch. Can be linked together to provide upto 10 μF in 1μF steps. External connections by 4mm socket terminals.

The motor cat no is mounted on a base with a driving wheel. Output is through 4 mm sockets and a low voltage bulb is also provided as a simple output indicator.

Mounted on panel, large size parts and visible wiring. Operates on 4-6 volts.

With one mains coil, 240 V, 50 Hz, 2400 turns and two interchangeable secondary coils 65 and 130 turns giving outputs of 6 and 12 V approximately at 2 A maximum.

As used in westminster electromagnetic kit. Size 90 x 50 x 22 mm.

With driving wheel, to generate current, mounted on polished wood base with driving wheel in vertical position , a lamp holder and a lamp. Output d.c. current.

With driving wheel, to generate current, mountedon polished wood base with driving wheel in vertical position , a lamp holder and a lamp. Output both D.C. and A.C. current.

Twin coil, in plastic cover, operates from 3 to 6 V. A.C./D.C.

A simple form of D.C. motor with 2 pole armature wound with insulated copper wire and a permanent magnetic field provided by a removeable bar magnet, with a commutator and phosphor bronze brushes connected to 4 mm sockets, open construction, all parts visible.

The motor consists of a two pole armature mounted between the ends of two bar magnets. The armature has a two section commutator and a pair of slip-rings on its shaft and is so constructed that the wire cannot slip off the iron core. The upper bearing and brushes for thecommutator are mounted on a strong upright. Separate brushes are provided for the commutator and for slip rings and each is connected to a terminal. The magnets are held in position by thumb screws.

For rapid measurement and hard use. Each dial has a zero position and 10 steps,with fully aged constantan coils. Accuracy ±0.1%.Available in wooden/metal box. Range 0.1 to 1,110 ohms.

Solid state electronic induction coil resulting in a very reliable and efficient system. There is no trembler contacts to wear or to require adjustment. Fitted with reversing switch. Operates on 220V A.C.25 mm, A.C.50 mm, A.C.75 mm, A.C.100 mm.

Coils are wound with highly insulated copper wire impregnated with paraffin wax, input 6-8 V d.c. through two 4 mm socket terminals, with an adjustable trembler system. The spark suppression capacitor is housed in the base. A pair of pointer electrodes with insulated handles for adjustement of the spark gap are provided. Spark Length 10 mm, 25 mm, 50 mm, 75 mm, 100 mm.

jockey
For Wheatstone bridge and potentiometer, with insulated handle, plated brass contact and a plated brass terminal with 4 mm socket.

For precision measurement of low resistances, range 10-4 to 1 ohm. With a rotary dial having ten coils of 0.1 ohm each and a circular slide wire resistance reading in steps of 0.001 ohm. A multiplier of 0.1 enables readings upto 0.0001 ohm. Separate current & potential terminals are provided. Properly aged manganin coils are used. Accuracy ±0.1% or ±0.2% of the slide wire length whichever is greater.

Porous pot filled with a mixture of manganese dioxide and carbon, and a zinc rod with brass terminal.

On base, with three terminals and pivoted contact arm with adjustable spring.

Mounted on polished wooden base, a convenient unit which is serviceable for a line as well when two such units are used.

Open construction, on wood base with two terminals, with two coils forming an electromagnet, tension adjustment on the armature.

To build 3 motor models as in Westminster electromagnetic kit consisting of 6 magnets,3armatures, 3 mild steel yokes, 3 support bases, 3 shafts,12 rivets, 6 split pins, 1 reel pvc tinned copper wire 26 swg, 1 reel sellotape, and 150 mm latex tubing 2 mm bore.

Wide spaced heavy gauge copper wire coil to carry current upto 10A is mounted on a base with 4 mm socket terminals. A platform is supported across the centre of the coil to show the field by use of iron filings or a small compass. Dimension of coil 150 x 50 mm diam.

Each centre tapped, wound on plastic former, to fit double ‘C’ core, with three 4 mm socketed terminals.

Each plate is fitted with a 4 mm socket terminal:

• Zinc 90x25x1.5 mm
• Copper 90x25x1.5 mm
• Lead 90x25x1.5 mm
• Carbon 90x 25 x 6 mm

Fitted with brass terminal:

• Zinc 90x25x1.5 mm
• Copper 90x25x1.5 mm
• Lead 90x25x1.5 mm
• Carbon 90x 25 x 6 mm

Platinum wire of about 2 ohms resistance, noninductively wound on a mica frame with copper leads, together with a pair of compensatory leads, all being connected to 4 mm socket terminals, for temperatures upto 150°C.

Plug type, with three pairs of ratio coils of 10,100 and 1000 ohms and 16 series coils from 1 to 5000 ohms, total 11,110 ohms, giving a range from 0.01 ohm to 1,111,000 ohms. Two tapping keys are provided for battery and galvanometer. Accuracy ratio coils ±0.05%, others ±0.1%.

With two ratio dials of 10,100 and 1000 ohms each and a resistance arm of four dials, each of ten coils of 1, 10, 100 and 1000 ohms, giving total resistance of 11,110 ohms, with 4 mm socket terminals for battery, galvanometer and unknown resistance. Highly stabel resistances are used. Accuracy ±0.1%.

A one metre long single resistance wire passes over a metre scale and is firmly clamped to stout brass end-plates,on wooden base. Complete with knife-edge jockey.

Four dial decade box with direct readout from 0 to 2 V, in four ranges. Two way switch for “Test” and “Standardise” sections, with coarse and fine current controls. With four pairs of terminals for connection to a 4.5 V battery, standard cell, galvanometer and the cell under test. Circuit diagram is printed on the panel. Accuracy is better than ±0.1%.

For Westminster Electromagnetic Kit giving 1 V full wave rectified d.c. and 1 and 2 V.a.c. outputs at 8 A max. The circuit diagram is printed on the top panel which also carries mains switch, light indicator and output sockets for d.c. and a.c. With 1.5 metre mains detachable cable.

All plugs are turned to a fine standard taper and are interchangeable. These are moulded in fluted plastic tops.The brass blocks are undercut and are fitted to a thick insulating plate.Heavy 4 mm brass terminals are used.Coils are non-inductively wound and are treated to be strain-free. Coil values are engraved on the plate and an infinity plug is also included.

With transparent cover, non-inductive visible winding, insulated support, with brass terminals. 0.1 ohm, 5 ohm, 0.2 ohm, 10 ohm, 0.5 ohm, 20 ohm, 1 ohm, 50 ohm, 2 ohm, 100 ohm.

With transparent cover, non-inductive visible winding, insulated support, with brass terminals. Square end supports. 0.1 ohm , 5 ohm, 0.2 ohm, 10 ohm, 20 ohm, 1 ohm, 0.5 ohm, 50 ohm, 2 ohm, 100 ohm.

As above, but with 4 mm socket brass terminals 0.1 ohm , 5 ohm, 0.2 ohm, 10 ohm, 20 ohm, 1 ohm, 0.5 ohm, 50 ohm, 2 ohm, 100 ohm.

In metal case, with plastic top and two current & two potential terminals. Accuracy ±0.05% 0.1 ohm, ±0.05% 0.2 ohm, ±0.05% 0.5 ohm, ±0.05% 1 ohm, ±0.05% 2 ohm, ±0.05% 20 ohm, ±0.05% 5 ohm, ±0.05% 10 ohm, ±0.05% 50 ohm.

Set of 12 preferred value carbon resistors with rotary selection switch, in box. Values are 33 ohms, 7 W: 100 ohms, 7 W; 330 ohms, 4 W; l Kohm 1W; 3.3 Kohm 0.5W; 10 Kohm, 33 Kohm, 100 Kohm, 330 Kohm,1 Mohm, 3.3 Mohm and 10 Mohm, all rated 0.25 W.

In black plastic round case, with two 4 mm socket terminals,

Accuracy:

• ±1% 0.1 ohm
• ±1% 5 ohm
• ±1% 0.2 ohm
• ±1% 10 ohm
• ±1% 0.5 ohm
• ±1% 20 ohm
• ±1% 1 ohm
• ±1% 50 ohm
• ±1% 2 ohm
• ±1% 100 ohm

In black plastic rectangular case, with two 4 mm socket terminals, accuracy ±0.5% 0.1 ohm, ±0.5% 5 ohm, ±0.5% 0.2 ohm, ±0.5% 10 ohm, ±0.5% 0.5 ohm, ±0.5% 20 ohm, ±0.5% 1 ohm, ±0.5% 50 ohm, ±0.5% 2 ohm, ±0.5% 100 ohm.

In plastic case 57x25 mm (diam x depth)with 4 mm terminals,one of which is fitted with a copper slotted lug for being connected to another unit,noninductively wound, adjusted to ±0.1% of nominal value.   0.1 ohm, 0.2 ohm, 0.5 ohm, 1 ohm, 2 ohm, 100ohm, 5 ohm, 10 ohm, 20 ohm, 50 ohm.

Single tube, for use with high voltage upto 220 V,fitted with 4 mm socket terminals, with protected cover.

A layer of oxidised resistance wire is wound on a porcelain tube which is supported by end supports. A sliding contact and three 4 mm socket terminals are provided for use as a rheostat or as a potentiometer. 200 mm, 300 mm.

Approx 1.8 ohms, is mounted on a tubular metal handle through which flexible leads pass.

The coil having 800 turns and a mean diam of 5.5mm is completely recessed near one end of a long prespex handle and connects to 4 mm socket terminals at the other end.

One copper and one zinc plate, size 90 x25 x 1.5 mm, each with a terminal, with battery jar of size 150 x 100 mm.

For rapid measurement and hard use. Each dial has a zero position and 10 steps,with fully aged constantan coils. Accuracy ±0.1%.Available in wooden/metal box:

• 0.1 to 1 ohm in steps of 0.1 ohm
• 1 to 10 ohms in steps of 1ohm
• 10 to 100 ohms in steps of 10 ohms
• 100 to 1000 ohms in steps of 100 ohms
• 1000 to 10000 ohms in steps of 1000 ohms

Set of two units. Each unit is fitted with one morse key, one sounder and on/off switch for battery, with two battery and two line terminals. All connections are visible. Each unit is workable on 4-6 volts D.C.

Set of two vertical units, each unit consists of a microphone, a receiver, bell and transformer, with visible wiring connections. Workable with 4- 6 V D.C.

Copper-constantan-copper, to form hot and cold junctions. Length of soldered junctions is about 38 mm The coiled lead is about 50 mm long.

Copper and constantan wires twisted together at one end and soldered for about 20 mm. Length of the coiled lead is about 50 mm.

Bars of bismuth and antimony soldered together with coiled connecting leads,which can be extended to 500 mm approx.

Comprising 112 copper constantan couples inseries and arranged in the form of a rectangle, with sensitive area of 18 x 22 mm. With a metal cone to increase directional selectivity. The inner surface of the cone is polished. With a pair of 4 mm sockets, on stand.The e.m.f. of the pile is of the order of 4 mV per °C difference between the hot and cold junctions.

Comprising 24 bismuth-antimony couples connected in series and in form of a rectangle, with cone, on stand.

Comprising transformer stand & sore, low voltage coils and main voltage coils, as detailed below:

Apparatus is designed primarily for demonstration of the basic principles of transformers. It consists of a laminated U-core with laminated I-core, both with 32 x 25 mm cross section to form a closed core of size 102 x 127 mm. Heavy aluminium alloy stand with removable clamping rods, 2 pole pieces, each 65x30 x25 mm with one end cone shaped, to accept support rod and shading ring. Poles also have a hole drilled through lengthwise to take a light beam.

For rapid measurement and hard use. Each dial has a zero position and 10 steps,with fully aged constantan coils. Accuracy ±0.1%.Available in wooden/metal box. Units and tens,total resistance 110 ohms, 11,000 ohms.

A very effective and motivating learning aid in elementary electromagnetism. Consists of 8 anisotropic alloy magnets, 8 ceramic ferrite magnets, steel magnet yokes, 6 plotting compasses, 4 hardboard formers to take compasses, 1 bottle iron filings 250 gm, 4 dispensers for iron filings ,4 double C-cores, 4 clips for C-cores,4 aluminium rings,4 aluminium split rings,4 armatures with axle tubes,4 aluminium axle rods, 8 split pins, 16 rivets, 4 formers for coils, 4 reels cellotape,4 reels copper wire, 4 sheets white pasteboard,4 plain postcards,4 reels white cotton thread, 1 length latex rubber tubing, 4 each resistors 100 ohms and 10 ohms,4 support bases,10 m.e.s. bulbs, 8 mes bulb holders,1 wood clamp, 1 wooden block, with instructions.

Four gap system, enabling two additional resistances to be interpolated in the additional gaps, enables greater accuracy of measurement by reducing unwanted resistances to a minimum.Two brass strips are provided to close the gaps when so required. Complete with jockey.

Comprising a resistance wire swg 24 stretched along a metre scale subdivided in mms and marked every cm.,is clamped to stout brass plates so as to avoid end errors. A plated brass strip with 4 mm socket terminal is fitted along the metre rule to provide a two gap system for normal wheatstone bridge work. Complete with jockey.

Enables students to investigate nature and properties of electricity by using simple circuits which are easily constructed on a base board. The connector system uses P.C.B. strips with cut-out sections whose ends can easily be inserted in spring terminals, ensuring low contact resistance and ease of connectlon. The kit consists of :

• 1 Baseboard, plastic. with spring
• terminals and three battery holders.
• 3 Batteries
• 10 Lamps 1.25 V m.e.s.
• 6 Lamp holders mounted on p.c.b.
• connectors
• 10 Plain connector p.c.bs.
• 1 Wire wound potentiometer with
• crocodile clip connections
• 1 Silicon diode
• 1 Resistor 3.9 ohm 2.5 W
• 1 pair Leads, red, with crocodile clip
• at each end
• 1 pair Leads, black, with crocodile clip
• at each end
• 1 pair Leads, yellow, with crocodile
• clips at each end
• 2 Switches mounted on p.c.b.
• connectors
• 2 Soft iron nails, 5 cm long
• 2m Bare copper wire, swg 20
• 2m Bare eureka wire, swg 34
• 2m Plastic covered copper wire
• 1 Electrode support
• 10 Pencil lead electrodes
• 1 Sheet copper foil, 150 mm square
• 1 Pack Steel wool
• 1 Instruction manual in English

Item Code: 10313Centre tapped, to fit ‘C’ core, with three 4 mm socketed terminals.

Item Code: 10293
Each wound on a rectangular insulated bobbin, connections by 4 mm sockets spaced at 19 mm 300 turns, 19 mm  600 turns.

Item Code: 10312As above but with 2400 turns, with three 4 mm socketed terminals.

Item Code: 10326
As above but mounted on base with insulated stand and terminals.