SIMPLE CELL 1601
A plastic jar 150x100mm (height x dia) with 150x150mm zinc and copper plates with terminals.

STANDARD CELL 1603
Portable, for use inside panel of instruments such as potantiometers, pH meters and other electronic instruments where internal standardisation is required. The cell itself is housed under engraved acrylic panel carrying red and black connecting terminals. Internal resistance 1000 to 1500 ohms. E.M.F. is 1.01859 Volts at 20ºC.

PLATES WITH TERMINAL 1610
For use in simple cell.
(a) Copper 150 x 50 x 2mm
(b) Zinc 150 x 50 x 2mm
(c) Carbon 150 x 38 x 5mm

BATTERY JAR 1611
Suitable for making simple cell. Cylindrical glass jar 150 x 100mm (Height x Dia.)

DANIEL CELL 1613
A copper vessel 150 x 100mm height x dia with a terminal and perforated shelf, a zinc rod with terminal and a porous pot 140 x 50mm dia complete.

LECHLANCHE CELL 1614
Comprises a plastic container 90x90x150mm Length x Width x Height. Rim shaped to hold a zinc rod as a cathode and a sealed porous pot containing a carbon rod with terminal in a mixture of powdered carbon and manganese dioxide. Require about 500ml of ammonium chloride as an electrolyte. Supplied without electrolyte.

STORAGE BATTERY UNIT 1616
To demonstrate principle of lead/acid ‘accumulator’. Glass jar, 250ml with plastic screw cap, carrying 4 mm socket terminals fitted to two lead plates.

ZINC ROD 1618
With brass screw and terminal 150mm long x 12.5mm dia.

LEAD ACCUMULATOR 1620
Storage type steady discharge of current not exceeding 0.75A, in polystyrene containers with terminals. Supplied uncharged without acid.
(a) 2V/20Ah
(b) 2V/45Ah.

LEAD ACCUMULATOR 1621
Multi-plate type. 2Volts 120amps. Hard rubber container with plastic lid and screw terminals. Supplied uncharged without acid. The above list does not include the entire range of instruments available, please feel free to request other items throughout this field.

NI-FE CELL 1622
Nickel-Cadmium cells reconditioned and uncharged with Emf 1.2 V per cell, housed in wooden crate of 2 cells. Capacity:
(a) 25 AH
(b) 45AH
(c) 75AH
Electrolyte for above cell available in 450 gms dry powder or 750ml solution.

HOFFMANN VOLTA METER 1626
See Chemistry Section. Cat. No. 6361.

ELECTROLYSIS CELL, OHP 1627
For use with an overhead projector to demonstrate the nature of chemical changes that occur with the electrolysis of aqueous solutions. Consists of a rectangular clear plastics container with two removable carbon electrodes, each fitted with 4mm sockets. A 6V, 0.03A M.E.S. lamp with flying leads and plug is fitted on the extension on one side of the cell. The cell can be divided by a separator that permits flow of the current but mechanically separates the products of electrolysis. Container size: 150 x50x55mm.

ELECTROLYSIS CELL 1628
Comprises a glass cylinder, 75x25mm diameter, fitted with a rubber bung carrying two carbon electrodes separated by an insulating strip. Two gas collection tubes, 75 x 10mm diameter, are suspended over the electrodes. Supplied with two crocodile clips.

DOUBLE ‘C’ CORE AND CLIP 1629
Laminated core to form a roughly rectangular core 92 x 56 x 20 mm approx. With a cross section of 20 x 12 mm & is cut across the middle to produce 2 equal ‘C’s. A strong spring steel strip is provided to hold the two halves together.

THERMOCOUPLE, COPPER-CONSTANTAN 1630
A simple junction of soldered wires, one each of copper and constantan, 0.5mm diameter x 500mm long. Watch wire coiled for convenience.

THERMOCOUPLE, BISMUTH-ANTIMONY 1631
Bars of bismuth and antimony each 20x3x3mm are soldered together and carrying connecting leads, 500mm x 0.5mm diameter, neatly coiled.

THERMO-PILE, COPPER-CONSTANTAN 1632
Approx. 150 junctions in a small area, the 'hot' face being exposed at the end of short tube 30mm x 30mm dia. A metal heat-collecting cone is attached at this end, the rear end carrying two 4mm socket terminals. Mounted on 13mm aluminium alloy rod 150mm long.

CONTACT KEY SINGLE 1635
A Phosphor bronze spring arm with press knob and two 4mm socket terminals. All mounted on a bakelite base 80x55mm. connected through stainless steel strip underneath.

CONTACT KEY DOUBLE 1636
A contact arm and three metal studs mounted on a bakelite base with three brass terminals. The centre terminal is common a connection to arm and the two other terminals are connected to other studs.

PLUG KEY, ONE WAY 1638
Two brass blocks 9mm thick with brass terminals mounted on a bakelite base 80 x 55mm. Accurately tapered plug with bakelite moulded top is fitted into the hole between the blocks.

PLUG KEY COMMUTATOR, 4 WAYS 1640
Circular, all brass parts on bakelite base.

KNIFE SWITCH SINGLE 1641
Single pole, double throw, mounted on bakelite base, with screw holes for bench fixing, etc. 3 pairs of connecting terminals. Dimension: 100 x15x30mm.

KNIFE SWITCH DOUBLE 1642
Double pole, double throw, mounted on insulating base with screw holes for bench fixing, etc. Dimensions: 100 x 38 x 30mm.

REVERSING SWITCH 1644
Rotary brush type switch with phosphor bronze contacts. Screw terminals. Maximum current 1 Amps. Mounted on an insulating base. Dimensions: 100 x100 x70 mm.

MORSE KEY 1645
Mounted on a wooden base it has adjustable pivots variable spring tension and variable movement. Three terminal posts are provided for make and break operation.

MORSE SOUNDER 1646
An open construction on wooden base with twin coils. Adjustment is provided on armature spring tension and movement, two terminals are provided for connection.

MORSE KEY AND SOUNDER (TELEGRAPH MODEL)1647
A combined version of above Morse key and Morse sounder.

RESISTANCE COILS 1650
Non-inductivity wound on plastic bobbin in transparent plastic tube with two screw terminals adjusted to + 0.2% rating Iw. Resistance in ohms:
(a) 0.1, (b) 0.5, (c) 1, (d) 2, (e) 5, (g) 10, (h) 20, (i) 50, (j) 100.

RESISTANCE COILS 1651
Ideal for classroom work involving accurate resistance measurement. Accuracy ± 1%. Fitted in a 55 x 110 high clear plastic jar. With 2 spin free head 4mm socket terminals at the Top. Standard values in Ohms:
(a) 1, (b) 2, (c) 5, (d) 10, (e) 20, (f) 50, (g) 100

RESISTANCE COILS 1652
In bakelite case with two terminals with values written in white. Bobbin non-inductively wound with double silk covered constantan wire. Accuracy ± 0.2%. Standard values in Ohms:
(a) 1, (b) 2, (c) 5, (d) 10, (e) 20, (f) 50, (g) 100

POST OFFICE BOX, PLUG TYPE 1660
The heavy brass contact blocks fitted to the bakelite plate. The inter-changeable plugs are cut to a fine taper. Each resister independently mounted with double leads wound with non-magnetic and non-inductive wire dipped in boiling wax. Provided with 3 ratio coils of 1000, 100 and 10 ohms, Rheostat arm 1-5000 ohms and two tapping keys for galvanometer and battery in polished wooden case with hinged lid of size 280 x 200 x 175mm. Accuracy: 0.05%

POST OFFICE BOX, PLUG TYPE 1661
Same as above but with 4 ratio coils. Accuracy: 0.05%

RESISTANCE BOXES, PLUG TYPE 1664
The heavy brass contact blocks are fitted to the vulcanite plate with double nut system. The plugs and lugs are cut to a fine taper and are inter-changeable Each resister independently wound with double leads. Accuracy of the Constantan coils is 0.1% for lower values 0.05% for higher values. Fitted in polished wooden box. Demonstration type with transparent sides is also available on demand.

	Range in Ohms	No. Coils	Total Resistance
(a)	0.1 to 1	9	2 or 1
(b)	0.1 to 1 or 1 to 10	5	2 or 20
(c)	0.1 to 5 or 1 to 50	8	11 or 110
(d)	0.1 to 10 or 1 to 100	9	21 or 210
(e)	0.1 to 50 or 1 to 500	12	111 or 1110
(f)	0.1 to 100 or 1 to 1000	13	211 or 1110
(g)	0.1 to 500 or 1 to 5000	16	1111 or 11110
(h)	0.1 to 1000 or 1 to 10000	17	2111 or 21110

RESISTANCE BOX DECADE TYPE SINGLE DIAL 1668
A dia sweeping brush contact, one for the main central contact and other for individual resisters, made from hardened copper phosphor bronze strips enforced by a spring strip are held in place by a rotating bakelite knob. The values of resisters are engraved on the vulcanite plate indicated by the index on the edge of knob at each click stop. Constantan wire, double wound resisters are dipped in boiling wax for constant values. Accuracy 0.1 % Ten steps of 0.1 ohm total 1 ohm, or Ten steps of 1 ohm total 10 ohms.

CONDENSERS (CAPACITORS) 1670
Mounted in teakwood box with plastic top with two terminals. Accuracy 1% w/o power factor.
(a) 0.001-0.01 mfds, (b) 0.02 mfds, (c) 1 mfds, (d) 2 mfds, (e) 5 mfds

DECADE CAPACITANCE BOXES (250V DC) 1680
Single dial
(a) 0.001 mF to .01 mF in10 steps
(b) 0.01 mF to 0.1 mF in 10 steps
(c) 0.1 mF to 1 mF in 10 steps
(d) 0.01mF to 10 mF in 10 steps

DECADE CAPACITANCE BOXES (250V DC) 1681
Two dials
(a) 0.001 mF to 0.11 mF in two decades
(b) 0.01 mF to 1.1mF in two decades
(c) 0.1 mF to 11mF in two decades

DECADE CAPACITANCE BOXE (250V DC) 1682
Three dials
a. 0.001 mF to 1.11mF in three decades
b. 0.01 mF to 11.1 mF in three decades

DECADE CAPACITANCE BOXE (250V DC) 1683
Four dials
0.001mF to 11.111 mF in four decades

FIXED INDUCTOR 1688
Ferrite core, resonant freq 1Kc, ±3%
1 to 10 mH max current 0.5 amp
11 to 100 mH max current 0.3 amp
0.11 to 1 Henry max current 0.1 amp

SINGLE DIAL INDUCTOR 1689
Ferrite core, resonant freq 1Kc, ±3%
1 to 10 mH in 10 steps max current 0.5 amp
10 to 100 mH in 10 steps max current 0.3 amp
0.1 to 1 Henry in 10 steps max current 0.1 amp
1 to 10 Henry in 10 steps max current 0.05 amp

TWO DIAL INDUCTOR 1690
1 mH to 10 mH in 10 steps max current 0.5 amp
10 mH to 100 mH in 10 steps max current 0.3 amp
10 mH to 100 mH in 10 steps max current 0.3 amp
0.1 H to 1 Henry in 10 steps max current 0.1 amp
0.1 H to 1 Henry in 10 steps max current 0.1 amp
1 H to 10 Henry in 10 steps max current 0.05 amp

THREE DIAL INDUCTOR 1691
Ferrite core, resonant freq 1Kc, ±3%
1mH to 10 mH in 10 steps max current 0.5 amp
10 mH to 100 mH in 10 steps max current 0.3 amp
0.1 H to 1 Henry in 10 steps max current 0.1 amp

FOUR DIAL INDUCTOR 1692
Ferrite core, resonant freq 1Kc, ±3%
1 mH to 10 mH in10 steps max current 0.5 amp
10 mH to 100 mH in 10 steps max current 0.3 amp
0.1 H to 1 Henry in 10 steps max current 0.1 amp
1 H to 10 Henry in 10 steps max current 0.05 amp

COMMUTATOR POHL’S 1695
Used in experiments on Hysterisis. Six cups for mercury in bakelite tray. Six terminals for connections and an insulating handle. Maximum current: 5 Amps.,
Dimensions: 140 x 140 x 80 mm.

SPADE TERMINAL ADAPTER 1701
To connect ordinary screw terminals for use with 4mm plug connectors. This adapter consists of a standard type of spade terminal integral with an insulated 4mm socket connector. A transverse 4mm connection hole is also provided enabling two connections to be made to the adapter.
Colour: (A) Red, (B) Black

INSULATED SOCKET TERMINAL (SPIN FREE TYPE) 1704
With moulded captive head, 4mm socket, nuts and washers. The screw top will clamp ordinary connection wires and spade terminals. Colour : (a) Red, (b) Black

SOCKET FOR BANANA PLUGS 1706
4mm, moulded hard plastic body, threaded with fixing nut. Plated brass insert with solder pin, Requires 8mm diameter panel hole. Maximum panel thickness l2mm.
Colour: (a) Red, (b) Black, (c) Yellow, (d) Green

STACKING PLUGS 1708
4mm, with screw connection for leads, longitudinal and transverse 4mm holes for extra plug connections. Hard plastic insulating body. Colour: (a) Red, (b) Black, (c) Yellow.

CROCODILE CLIP 1709
With strong spring and clamping screw for wire.

MAGNETIC EFFECT DEFLECTION 1710
Running cathode rays are visible to naked eye by the glowing path on fluorescent screen. When a magnet is brought near, the deflecting path cathode rays are vividly visible. Supplied without magnet

HEATING EFFECT WAX COATING 1711
When cathode rays are focused on wax coated on the outside of the upper round head of cathode ray tube, the wax melts quickly showing heat generated by cathode rays.

PLUG LEADS 1712
4mm plugs connected by a length of flexible, plastic insulated copper wire. The plugs are stackable. Colour: Red, Black, and Yellow.
Length: (a) 300mm, (b) 500mm, (c) l00mm.

GEISSLER'S TUBES DEMONSTRATION 1713
Different shapes and degree of vacuum inside showing different discharge phenomenon, illuminations, patterns etc. Tube ends provided with caps for connection to induction coil. Set of 6 tubes.

GEISSLER'S TUBE 1714
For use with electronic machine or induction coil, with vacuum regulating device. Comprises a glass sphere with a concave disc electrode generating cathode rays and focusing on a tungsten target, placed at an angle of 45° at the inner end of arm exactly opposite. These tubes produced soft X-Rays and care must be taken from over exposure. Available in following diameters: A). 80 mm , B) 90 mm, C) 110 mm.

SPECTRUM TUBES 1715
20 cm long straight form, with side electrodes and 50 mm long fine capillary in the middle. Filled with Oxygen, Neon, Helium, Air Nitrogen, Argon, Ammonia Vapours, Alcohal Vapours, Carbon Dioxide, Hydrogen, Iodine vapour, sulpher water vapours.

RECTILINEAR PROPAGATION 1716
V Shaped tube. To show cathode rays are generated only vertical (lower electrode) irrespective of the anode points (any of two electrodes above).

REPULSION TUBE GOLD STEIN'S 1717
Vertical tube with two parallel wire cathode at two ends of tubes with third electrode to serve as anode. Mounted on base.

SHADOW EFFECT ELECTROMAGNET 1718
An object obstructing cathode rays casts its shadow on the fluorescent wall facing it, and if the running cathode rays are subjected to magnetic effects, per an electromagnet, the shadow is affected by its slight rotation change. Complete with electromagnet.

REPULSION TUBE GOLD STEIN'S 1719
Vertical tube with two parallel wire cathode at two ends of tubes with third electrode to serve as anode. Mounted on base.

FLASH LAMP BULBS 1720
With M.E.S. cap, suitable for flash-lamps, sport lights and panel lamps etc. Supplied in packs of ten. Volts:
(a) 1.5 V, (b) 3.0 V, (c) 4.5 V, (d) 6.0 V

FLASH LAMP 1721
2.5 Volts mounted in M.E.S. holder fitted in clear plastic jar of 55 x110mm with two 4mm sockets on top.

SHADOW EFFECT MALTESE CROSS OR CROSS & SHADOW 1722
An object (star) obstructing the path of cathode rays casts is shadow on the fluorescent painted wall facing cathode rays.

HEATING EFFECT PLATINUM FOIL 1723
Upon focusing at a point, cathode rays generate intense heat shown by the red heating of platinum foil.

CARBON ARC LAMP 1724
Mounted on wooden base to explain working of arc lamp operates on 12 volts A.C./D.C.

LAMP HOLDER M.E.S. 1725
To take flash lamp bulbs, moulded plastic base with two screw connections.

LAMP HOLDERS, MOUNTED 1726
S.B.C. double contact brass lamp holder mounted on rectangular base, with two 4mm socket connections. Dimensions: 100 x 60 x 60mm high.

WORCESTER CIRCUIT BOARD 1730
Consists of a base-board, complete with terminals, a set of metal connection pillars and a number of clips on flexible connection strips and accessory units, enabling a wide variety of electrical circuits to be constructed quickly and easily. The phosphor-bronze strips are so designed that when flexed a little in the fingers, they are easily slipped over the pegs where their natural spring holds them firmly in position and ensures a good electrical contact. The following components are supplied with each board. 20 Flash lamp bulbs,1.25V 0.25A, 9 connectors with lamp holder, 12 Plain connectors, 1 Connector with rheostat, 1 Rectifier, 1 Resistor, 2 Flexible leads with 4 mm plug and crocodile clip, 2 Flexible leads with crocodile clips, 2 Crocodile clips, 2 Mounted bell pushes, 2 Soft iron nails, 50 mm, square head, 1 Length bare copper wire 20 SWG, 1 Length plastic covered copper wire 26 swg, 1 Plastic disc drilled, 4 Pencil leads, 1 Piece copper foil, 1 Piece steel wool. The standard pack is one complete set as detailed above. sufficient for two students.

WATER CIRCUIT BOARD 1732
It consists of a large board on which is mounted a low-voltage electric pump, connected to 4 mm socket terminals, which circulates the water through the circuit. The circuit is of clear plastic tubing connected to glass tubes of differing bores representing resistances. Across the resistance is connected a detachable manometer to show the potential difference. Following the resistance is a taper-ended tube discharging into a funnel so that the rate of flow representing the current may be shown. Dimensions: Board 590 x 320mm approx., Manometer 275 x 115mm approx.

BICYCLE DYNAMO ASSEMBLY 1733
For showing slow A.C. on an oscilloscope or meter or for demonstrating the use of a dynamo mounted in lighting a lamp. This apparatus has a cycle dynamo mounted on a base and provided with two sets of gears driven by a hand crank for fast and slow rotation. Two 4 mm socket terminals are provided for the dynamo output, connected in parallel with an M.E.S. lamp holder and 2.5 V bulb Dimensions 220 x 115 x 105 mm high

ELECTRIC MOTOR KIT, WESTMINSTER TYPE 1734
The kit comprises all the part required to build 6 model motors as in the electromagnetic kit. Each kit contains:
- 12 pieces of magnets;
- 6 pieces of armatures;
- 6 pieces of mild steel yokes;
- 6 pieces of support bases;
- 6 pieces of shaft;
- 24 pieces of rivets;
- 12 pieces of split pins;
- 1 reel of 26 SWG PVC tinned copper wire;
- 2 reels of cellotape;
- 300mm rubber tubing;
- 3mm bore

DEMONSTRATION ELECTRIC MOTOR 1735
A completely open construction model of motor. The field is provided by a Permanent magnet armature wound by enameled copper wire provided with a commutator and Phosphor bronze brushes for supply of current to the armature from two 4mm socket terminal. The motor operates on 4.5 to 9 Volts DC.

TELEGRAPH SET, LECTURE PATTERN 1736
Set of TWO units working model, each unit is mounted on wooden polished vertical stand, all connections are clearly visible to explain the principle of telegraph. Each unit is workable on 4-6 volts D.C.

BELL DEMONSTRATION MODEL 1737
All the components of an electric bell are mounted on a large panel. All wiring is visible and parts are of large size. Operates on 3-4 volts D.C.

ELECTRIC MOTOR WITH NEWTON’S DISC 1738
Mounted on a wooden base 90 x 90 x 100mm, length x width x overall height. A three pole armature wound with enameled copper wire provided with phosphors bronze brushes to carry the current from two 4mm socket terminals working on 3 to 6 Volts.

DYNAMO MOTOR MODEL 1739
A versatile model to demonstrate the working of both dynamo and motor. Driven with a rubber belt on a hand wheel a two pole armature rotates in a magnetic field provided by a permanent magnet. The D.C. current thus produced glows a torch lamp at two 4mm sockets. To demonstrate the apparatus as a motor the belt is taken off and a DC current of 4 to 6 volts is applied at two 4mm sockets which sets the armature is motion. All fitted on wooden base.

SMALL MOTOR/GENERATOR 1740
For use with the large motor/generator in comparing power input and output by driving each in turn with the other and metering the voltages and currents. Uses a smaller 1.5 to 4.5V motor. Dimensions of laminated wooden base 155 x 105 mm.

LARGE MOTOR/GENERATOR 1741
For use as a tlriving unit or dynamo. Comprises a 2 to 6V DC, motor provided with a l50mm diameter V pulley. Dimensions of laminated wooden base 155 x 105mm.

ELECTRIC MOTOR KIT 1742
Small version of D.C. electric motor. Construction can be done by student by joining all parts contained in plastic box and can be dismentelled easily Workable on 4-6 volts.

SOLAR CELL UNIT 1745
High output solar cell connected to a low inertia electric motor and connected through 4mm terminals to allow electrical calculation of energy output/consumption levels. Can also be used in energy conversion experiments with provision for metering current.

SOLAR MOTOR WITH FAN 1746
See Solar and Wind Energy Section.

ELECTRONIC CIRCUIT TRAINER KIT 1747
Comprises range of Resistance, Capacitor, Diode Transformer Inductor, Potentiometer, Switch and Transistor etc., on insulated panel with pin contacts for component connection. A bunch of connecting leads is provided to makeup the experiment. Also a wooden storage box.

DEMONSTRATION CAPACITOR (zener diode) 1748
Comprises two capacitor plates with accessories.

P-N-P and N-P-N TRANSISTOR UNIT 1749
Mounted on transparent base, with 4 mm colour coded sockets, with circuit diagram printed for demonstration.

WHEAT STONE BRIDGE 1750
The bridge is a self contained unit with the measuring range 0.001 to 11.11 meg ohms built in Galvanometer by measuring resistances it contains with 4 decade series dials of 10x1, 10x100, 10x1000 ohms with single ratio dials of 0.001,0.01,.1,1,10,1000 ohms giving multiple ratio.

INDUSTRIAL DOUBLE KELVIN BRIDGE 1752
The bridge is for measurement of low resistance, such as shunt resistance determination with current up-to 10amp.
Measurement Range: 0.2 Micro Ohms to 11 OHMS
Multiplier Range: In 5 multiple of 0.01, 0.1, 1, 10, 100 Ohms. Main Dial: It comprises a single dial of 10x0.01 Ohms with slide wire of 0.01 Ohms with circular scale having 100 Main divisions. The scale is further Sub divided into 500 equal parts each small division (at Ratio XI) represents 0.00002 Ohms or 0.2 Micro Ohms. The slide wire is fitted with a SILVER CONTACT to eliminate the contact resistance error. A terminal is provided on the disc fitted on the circular scale for True Zero setting. Complete with Conductivity attachment, Spot Reflecting Galvanometer, Heavy duty Source 10 Amp. with working manual & 2 potential leads.

KOHLRAUSCH CONDUCTIVITY BRIDGE 1755
For determining the Electrolytic conductivity & Resistance. Main Features: A circular Slide wire is calibrated from 0 to 10 ohms. A ratio dial with six multiple ratios of 0.1, 1, 10, 100, 1K & 10K Ohms is connected in series with the slide wire giving 0.01 to 100K ohms with Electrolytic cell with two platinum black coated electrodes. Complete with Audio Oscillator and Head Phone.

HUMBERGER CELL (Conductivity Cell) 1755A
Dip type with platinum electrodes, for use with above Bridge

VOLTAGE MEASUREMENT USING POTENTIOMETER 1760
Crompton Potentiometer Measurement up-to 1.75V (can be measured up-to 300V with the help of volt ratio box) Complete with one coars

MAXWELL'S INDUCTANCE -CAPACITANCE BRIDGE 1763
Maxwell's Bridge for measuring Self Inductance. Main Features: -Two ratio dials of 1, 10, 100, 1000 ohms each are connected to 3 decade dials of 10, 100, 1000 ohms. One ratio is shunted with capacitance arranged in 3 decade dials over the range of 1.11mfd. The fourth arm is having 3 more decade dials of 0.1, 1 to 10 ohms & working Instruction. Accuracy of Calibration ±0.1% with audio oscillator & head phone.

OWEN'S BRIDGE 1764
For measuring Self inductance in terms of standard Capacity and resistance. Main Features: A plug-in type resistance bar, having range from 1 to 500 ohms, forming one arm of the bridge is connected in series with four decade dials over the range of 1, 10, 100 & 1000 ohms and Unknown Inductance. Four decade dials of 0.1, 1, 10 & 100 ohms are connected to a standard Capacitance dial over the range of 0.1x 10 Mfd Constitutes the 3rd arm of the Bridge. The 4th arm Contains one more standard Capacitance dial in the form of single decade 0.1x10 Mfd. Complete with audio oscillator & head phone.

HAY'S BRIDGE 1765
Measuring Inductance Coils of Large Time-Constant. A fixed resistance of 1kohm is connected in series with three decade capacitance of 0.0001mfd., 0.001mfd & 0.1 Mfd constitute one arm of the bridge. The second arm contains two resistance decade dial of 10 and 100 ohms. The third arm contains three decade resistance dials of 1kohms,10kohms and 100kohms. The experimental inductance is placed in the remaining arm with audio oscillator & head phone

CAREY FOSTER'S BRIDGE 1766
For Measuring mutual inductance in terms of capacitance & resistances. The 2 arms of the bridge comprises 3 decade dials of 10,100 & 1000 Ohms each. The other arm contains a standard variable capacitance in series with a decade resistance box Connections are provided for connecting two Inductances, AC supply & head phone. Complete setup with audio oscillator of 1 kHz, head phone & two self inductance to make them an experimental mutual inductance.

WEIN'S SERIES RESISTANCE BRIDGE 1767
For measuring Capacitance & Resistance of a Condenser.
Main Features: Two decade dials of 100 ohms each constitute two arms of the bridge. The third arm Contains 4 decade dials of 0.1, 1, 10 &100 ohms each constitute two arms of the bridge. The third arm Contains 4 decade dials of 0.1, 1, 10 &100 ohms Connected in series with a standard Capacitance arranged in single decade of 0.1x10 Mfd. the remaining arm contains 4 decade dials of 0.1, 1, 10 &100 ohms which are connected to the unknown capacitance. Complete with un known capacitance, audio oscillator and head phone.

DESAUTY'S BRIDGE 1768
For measuring of capacity with ratio of R1 & Series dial of R2 and one variable capacitor with Audio Oscillator, Air & Dielectric Capacitor and Head Phone Schering bridge Kit :- Measurement of small Capacitance A plug type resistance bar having 10, 20, 50,100, 200, 500, 1000, 2000 & 5000 ohms is connected in series with 4 decade dials of 0.1, 1, 10 &100 ohms. A variable capacitor with calibrated dial is connected in parallel with the four dial decade dials. A four dial capacitance box over the range of 0.001, 0.01, 0.1 & 1x10 Mfd is included in the circuit with working manual but with oscillator & head phone.

FREQUENCY BY WEIN BRIDGE 1769
Two decade dials of x10 & x100 is connected in parallel to 2 decade capacitance dials of x0.1 Mfd & 1Mfd. Constitute one arm of the Bridge. Two more decade resistance dials of x10 & x100 constitute the second arm of the bridge. The third arm comprises 2 decade dials of x100 & x1000 ohms. The fourth arm contains 2 capacitance dials of x0.1Mfd & 1 Mfd, Connected in series with 2 Terminal. An unknown resistance is connected to these terminals. Complete with Audio Oscillator & Head Phone.

PLATINUM RESISTANCE THERMOMETER 1770
Corning glass tube in valvet case. Resistance approx 2.8ohms. With copper leads.

POTENTIOMETER 1 WIRE 1771
Slide wire pattern with one wire stretched on a box wood meter scale 0-l00cm x 1mm. With two 4mm socket terminals fitted on a polished wooden base. Supplied with a knife edge jockey.

JOCKEY KNIFE EDGE 1771-A
A brass nickel plated knife edge mounted on a bakelite handle 90mm long x l2mm dia with a terminal at the upper end.

POTENTIOMETER 4 WIRE 1772
Four constantan wires 24 SWG stretched on a polished wooden base connected in series with the help of brass strips provided with two 4mm socket terminals. A box wood meter scale fitted on one edge of the wooden base parallel to one meter length of 4 wires with a knife edge jockey.

POTENTIOMETER DECADE PATTERN 1773
Eight steps of 2 ohms and a slide wire of equal resistance enclosed, circular type, divided into 200 parts and calibrated to read in millivolts all in series and with coarse and fine rheostats provide the standardizing unit. Terminals are provided for standard cell, galvanometer and two 1.5 volts batteries and two sets of external test circuits, worked by a rotary switch. Standard cell is got into circuit without alteration to the list circuit. Range of measurement 0.0005 to 1.8 volts accuracy 0.05%

RHEOSTAT SLIDING CONTACT 1774
The electrically oxidised eureka wire is wound on perfectly round 43mm dia porcelain pipe according to length required. The vulcanite/Aluminium hexagonal/round supports light the pipe on each side with a rod and nuts. The guide rod carrying the contact block is lightened with screws to the projection of the supports and carry the third terminal which permits the instrument to be used in any step. The contact block carries smooth phosphor bronze brush contacts. The instrument is perfectly insulated.

	Max Amps	Max Ohms	Tube Dia mm	Tube Lenght mm
(a)	6.5	4.4	43	200
(b)	5.0	11	43	300
(c)	4.2	12	43	200
(d)	3.3	16	43	200
(e)	3.3	27	43	300
(f)	2.3	56	43	300
(g)	1.6	50	43	300
(h)	1.6	100	43	250
(i)	0.8	160	43	150
(j)	0.8	240	43	200
(k)	0.3	1700	43	200
(l)	0.3	2850	43	300
(m)	8.2	2	56	150
(n)	8.2	4.5	56	250

RHEOSTATS 1776
Extra superior quality wounded on super enameled hexagonal metallic pipe and insulated ends with carbon sliding contacts. All the above mentioned are available.

RHEOSTAT, SINGLE TUBE, PROTECTED 1777
Variable up-to 345 ohms at 1.2A rating, for use as a series resistor or a Potentiometer Enclosed type, in metal case with windings on porcelain former 350mm long x 56mm dia, three 4mm socket terminals and four mounting lungs topped OBA.

MULTI METER DIGITAL 1778
Specifications
D.C. Voltage : 200mV-1000V ±0.5%+2
A.C Voltage : 200V-750V ±1.2%+10
D.C. Current : 200µA-10A ±1%+2
Resistance : 200 Ohm-2000kohm ±0.8% +2
Maximum Display : 1999
Display Size : 16x48mm
Range : Manual
Transistor Test : Yes
Standard Accessories : Battery, Resting Probes.

MOVING COIL METERS 1780
For DC measurements, designed for use in schools, colleges and technical institutions. All Meters are housed in moulded, ABS plastic/bekelite dust proof cases, with zero adjuster accessable front and Terminals for connections. The Meters are of 4 different types as described hereunder : at a, b, c and d.

(a) Case: ABS plastic/bakelite round Meter. Accuracy: Class 2.5, Scale: Length 50mm, Overall Size: 100x 90x 90mm approx. available in Single range only.
(b) Case: ABS plastic/bakelite round Meter. Accuracy: Class 2.5, Scale: Length 50mm, Overall Size: 100x90x125mm approx. Single/Double/Triple range.
(c) Case: ABS plastic/bakelite square Meter with acrylic front cover. Accuracy: Class 2, Scale: Length 60mm. Overall size: 100x90x125mm approx. Single/Double/Triple range.
(d) Case: ABS plastic/bakelite rectangular meter with acrylic front cover. Accuracy: Class 2, Scale: Length 85mm. Overall Size: 110x100x140mm approx. Single/Double/Triple range.

Measuring Ranges for the above Meters:
MILLI-AMMETERS: 0.1, 1.5, 3, 5, 10 Amps.
MICRO-AMMETERS: 0.1, 5, 10, 25, 50, 100, 250, 500 mA
VOLT METERS: 0.1, 5, 10, 25, 50, 100, 250, 300 Volts
MILLI-VOLT METERS: 0.25, 3, 5, 10, 25, 50, 100, 250, 500 mV
GALVANOMETERS: 1-0-1 mA, 35-0-35 mV, 3.5-0-3.5 mA

DIGITAL BENCH METER 1781
Digital meter for general purpose laboratory use housed in tough case use of a 3½ digit cover most of the ranges. Main operated
Display: 13mm characters
Accuracy: ±0.3% typical
Linearity: 0.2% typical
Dimensions: 82x130x100mm
(Multi range digital meters both in AC/DC. can also be supplied on demand)

DUAL AMP/VOLTMETER 1782
A versatile dual purpose bench meter with an analog quadruple range (-5 to 0, 0 to 50, -10 to 0 and 0 to 100). A choice of volts or amps reading is made via a slide selector, which automatically selects the appropriate internal shunting, also guarding against incorrect connection by securing the input sockets. Input is via 4mm. sockets of screw terminal connectors. Zero adjustment is via a screw situated on the front of the meter. Technical Specification:
Amp Inputs 100µA, 100mA, 1A, 5A.
Volt Inputs 100mV, 1V, 10V, 50V.

MOUNTED JOULE METER 1783
A domestic electricity meter adopted to operate single-phase 2, wire CI.2 mA x 8.33 A 12 V 50 Hz 0.01 rev/J and dials reading in joules. The meter is mounted on a robust bench stand with 4 mm input and output socket terminals. The aluminium disc rotates once for every 100 joules with the consumption recorded on three digits calibrated 100,1000 and 10000 joules per division respectively. The instrument records a maximum of 99,900 Joules.

SEARCH COIL 1784
The Coil is wound on a moulded plastic ring & mounted on a tubular plated metal handle through passes the 1 meter long flexible leads. Wound with insulated copper wire, the coil has a resistance of 1.8 ohms approx. The mean dia is 34 mm & the number of turns 100 are clearly marked on the coil former. Dimensions : 150 x 40 x 60 mm.

PORTABLE METERS 1785
150 mm mirror scales in wooden box with carry around strap handles, most popular in technical schools. These are large size carry around meters with knife pointer, it's movement resting on synthetic sapphire jewels in hardened alloy Pivots, chemical treated and aged hair spring. Accuracy of these meters conformed with in ±1%.. Overall Dimensions: 240mm x 200mm x 110mm approx. Portable moving coil Ammeters, Voltmeters and Galvanometers in Single/Double/Triple ranges as per buyer's requiremet available.

DEMONSTRATION METER 1788
A demonstration meter that can be converted into an AC or DC Voltmeter or Ammeters with selection of ranges for each mode of operation by using interchangeable dials which fit through a slot in the side of the case. The movement is housed in a robust hardwood case. All working parts are clearly visible through front and rear glass panels. A zero adjustment device permits instrument to be used for centre zero working. Accuracy +2.5 FSD. Dimensions: 320x140x305mm. Supplied without dials.

SCALES INTERCHANGABLE FOR DEMONSTRATION METER 1789
A plastic panel 313x117mm with sealed moulded box at one end which contains shunt or voltage multiplier appropriate to the scale. AC or DC current
(a) 0-l 0 ma, (b) 0-50ma, (c) 0-100ma, (d) 0-500ma, (e) 0-1a, (F) 0-5a

SCALES INTERCHANGABLE FOR DEMONSTRATION METER 1790
A plastic panel 313x117mm with sealed moulded box at one end which contains shunt or voltage multiplier appropriate to the scale. AC or DC Volts
(a) 0-5v, (b) 0-10v, (c) 0-15v Note: Other ranges also available.

CHARGE AND DISCHARGE KEY 1795
Used in charging and discharging of a capacitor. C.P brass strips and pillars Three terminals fitted on a thick bakelite plate of high insulation. Contact Resistance: 2 milli ohms approx. Maximum current: 5 Amps., Dimensions: 185x15x45mm

NICHROME WIRE, BARE 1792
A nickel - chromium - iron alloy specially suitable for high temperature applications such as heating elements, rheostat, etc.125gms. each reel of following SWG
(a) 18, (b) 20, (c) 22, (d) 24, (e) 26, (f) 28, (g) 30, (h) 32, (i) 34, (j) 36

NICHROME WIRE (SUPER ENAMELED) 1794
Standard grade Ni/Cr wire enameled for bearing higher temperatures. In plastic spools. Available in all common gauges i.e. in 50/100 gm spools, SWG 20, 22, 24, 26, 28, 30, 32.

COPPER WIRE, BARE 1798
Copper wire of 125 gms each reel of the following:
SWG (a) 18 SWG, (b) 20 SWG, (c) 22 SWG, (d) 24 SWG, (e) 26 SWG

COPPER WIRE DCC 1801
Double cotton covered, available in 50/100/200gms spools, in: 22, 24, 26, 28 SWG

LAMP UNIT, TRIPLE 1805
Three lamp holders are connected in parallel. Supplied complete with three lamps 1.25V 0.25A, M.E.S. Dimensions of laminated wooden base 155x105 mm.

SWITCH UNIT 1808
A double-pole double-throw knife switch for connecting the motor/generator. The socket terminals are labeled battery, motor and lamp respectively. Dimensions of laminated wooden base 155 x 105 mm.

RESISTANCE THERMOMETER, PLATINUM 1812
Comprises a fine platinum foil wound on a frame, together with two compensating leads, all enclosed in a test tube. All four leads are connected to 4mm sockets which are mounted on a small panel at the top of the tube, 150 x 25mm.

RESISTANCE SUBSTITUTION BOX 1813
Range 100 ohms to 10 M given by 16 preferred value carbon resistors 100, 200, 470 ohms, 1, 2.2, 4.7, 10, 22, 47, 100, 220, 470 k ohms, 1, 2.2, 4.7, & 10 M ohms. Rating 0.5 W continuous, 1W max. In wooden case 90 x 90 x 40 mm with rotary selector-switch having on/off position & a pair of 4 mm sockets & 19 mm spacing on the top panel.

CAPACITANCE RESISTANCE BOX 1814
With 12 non-polarized preferred value capacitors mounted on a small baseboard with terminals for connecting in a circuit. With rotary switch and a pair of 4 mm socket terminals. Range 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.

DC REGULATED POWER 1815
Solid state, high voltage With Square meters, Tight regulated
(a) 0-300V DC at 50mA, bias 30V at 50ma, LT 6.3V 2amp AC with 2 meters
(b) As above with 3 meters
(c) 0-300V DC at 100ma, bias 30V at 50ma, LT 6.3V 2amp AC with 2 meters
(d) As above with 3 meters
(e) 0-300V DC at 200ma, bias 50V at 100ma, LT 6.3V 3 amp AC with 3 meters

DC REGULATED POWER 1815-a
Same as Cat No. 1815 but with digital display.

LOW VOLTAGE DC POWER SUPPLIES 1818
Load regulation 0.05%, square meters, cv/cc operational 0-30V at 500mA
(a) 0-30V at 1amp
(b) 0-30V at 2amp
(c) 0-30V at 3amp
(d) 0-30V at 5amp

DUAL TRACK DC POWER SUPPLIES 1820
with 2 square meters, 4 meters 0-30V at 500mA
(a) 0-30V at 1amp
(b) 0-30V at 2amp
(c) 0-30V at 5amp

STABILIZED BATTERY ELIMINATORS 1822
(a) 2-12V at 500mA
(b) 2-12V at 1amp
(c) 2-12V at 2amp
(d) 2-12V at 3amp

FIXED OUTPUT DC SUPPLIES W/O METER 1824
(a) 5V at 1amp, 2amp, 3amp
(b) 12V at 1amp, 2amp, 3amp
(c) 24V at 1amp, 2amp

STUDY OF POWER SUPPLIES 1827
• With built in power supply and meters as specified.

• Half wave/Full wave rectifier, with 3 meter & also in 2 meter 1827/1

• Bridge rectifier, with 3 meters & also in 2 meter 1827/2

• Diode rectifier and filter characteristics (L, Pi, Capactive) 3 meters 1827/3

• Zener Diode characteristic Apparatus with Power Supply 1827/3a

• Transistor regulated power supply 2 meters 1827/4

• Study of voltage IC 723 with 2 meters 1827/5

• Three terminal voltage regulator 2 meters 1827/6

• Study of IC regulated power supply 2 meters 1827/7

• Voltage doubler, tripler, 2 meters 1827/8

• S.C.R phase control (Resistive load, U.J.T rex,2 S.C.R) 2 meters 1827/9

• S.C.R regulated DC power supply 2 meters 1827/10

• TRIAC phase control (lamp, fan not included) LINE operated,1 MI meter1827/11

• Low capacity S.C.R inverter with DC supply and 2 meters (load extra) 1827/12

• As above transistor used instead of S.C.R 1827/13

• dV/dt limitation of S.C.R with HV supply 1827/14

• Study of SMPS 1827/15.

FLY-WHEEL UNIT (MALVERN) 1828
For use with a large motor/generator and a lamp unit to demonstrate the conversion of electrical energy to kinetic energy and then back again. Comprising an iron flywheel 115 mm dia., mass 1.2 kg, mounted in cast brackets with bearings. The shaft has an aluminium pulley 44 mm dia., for driving with the spring belt supplied. (Pic 1).

LAMP UNIT, TRIPLE (MALVERN) 1829
For use with motor/generators to give an indication of their output when used as dynamos. The lamp-holders are connected in parallel. Supplied with three lamps 3.5V 0.25A, M.E.S. (Pic 2).

LARGE MOTOR/GENERATOR (MALVERN) 1830
For use as a driving unit or dynamo. Comprises a 2 to 6 V D.C. motor provided with a 15 mm dia. pulley. Supplied with driving belt. (Pic 3).

SMALL MOTOR/GENERATOR (MALVERN) 1831
For use with the larger motor/generator in comparing power input and output by driving each in turn with the other and metering the voltages and currents. (Pic 1).

LINE SHAFT UNIT (MALVERN) 1832
For showing the conversion from electrical energy, via mechanical, to potential energy by winding up a weight on a cord. One end of the 6mm steel shaft carries an aluminium 'V' pulley 56 mm dia., and the other end is fitted with a cord anchoring collar. Supplied complete with driving belt. (Pic 2).

TURBINE/PUMP UNIT (MALVERN) 1833
For use as a water turbine to drive a generator producing electricity or for use as a pump driven by a motor and raising a head of water to produce potential energy. The rotor has eight bucket blades and is housed in a block turbine chamber 50 x 50 x 25 mm, with a clear Perspex front. Two inlet tubules (for turbine and pump operation respectively) and one outlet tubule are provided, and the shaft carries a 15 mm dia. pulley. With driving belt. (Pic 3).

SPRING UNIT (MALVERN) 1834
For showing potential energy in a wound-up spring and its conversion to electrical energy by driving a dynamo and lighting a lamp. May also be used to wind up a weight on a cord showing the change from potential energy to kinetic and back to potential in the raised weight. The steel shaft carries a clock spring with a free wheel device and winding ratchet also an aluminium ?V? pulley 56 mm dia.. One end of the shaft overhangs the base for use as a line shaft when winding up a weight. Dimensions 220 x 100 x 100 mm high. Supplied complete with driving belt. (Pic 1).

HAND WHEEL DRIVING UNIT (MALVERN) 1835
For use in driving dynamos, line shafts, flywheels, pumps etc. the driving and output pulleys are both 75 mm dia., and the intermediate pulley is 20 mm dia. giving a step-up ratio of 3.75. (Pic 2).

HEAD OF WATER UNIT (MALVERN) 1836
For use with turbine pump unit to provide an open or closed system in demonstrating the conversion from electrical to kinetic energy in the pump and potential energy in the head of water. Supplied complete with two basins 80 mm dia. and shaped glass tubes. The upper platform has 38 mm dia. hole to allow use as a simple re-circulation system with a single reservoir.

RHUMKORFF'S COIL 1839
High quality, trembler type spark coil. comprising primary of few turns of heavy wire wound on iron core, mounted horizontally, which is fed by DC current pulses. Secondary coil of very large number of turns of very thin gauge wire completely encompasses the primary and is impregnated with wax. The electromagnetic induction due to current passing through the primary makes the armature oscillate resulting in frequent switching ON/OFF of the current through primary. This produces extremely high rate of change of magnetic field in this Rhumkorff's coil, giving rise to a potential of several thousand volts in secondary, which is observable in the form of repetitive spark up to 25mm long across adjustable needle. Provided with a safety spark gap beneath needle socket terminals to protect internal damage to the coil against very high voltages. Output from the terminal can also be used to operate high voltage devices such as spectrum tubes etc. operates on 6-9V DC.

DIELECTRIC CONSTANT APPARATUS 1840
To calculate dielectric constant of liquids and solids. The instrument consists of high frequency oscillator of tunable with outer gang condenser optimum tuning is indicated on meter. The change after placing dielectric between parallel plates is again detected and difference noted for calculation.