102.1 Diode Unit : With silicon diode mounted on base as described.

102.2 Zener Diode Unit : With zener diode mounted on base as described.

102.3 P.N. Junction Unit : With P.N. Junction diode mounted on base as described.

102.4 Solar Cell Unit : For use with mini-motor unit. Silicon photoelectric cell mounted on base as described.

102.5 Photo Voltic Cell Unit : With photo voltic cell mounted on base as described.

102.6 Cadmium Sulphide Resistor Unit : With photo-sensitive resistor mounted on base as described. Resistance inversely proportional to light intensity.

102.7 N-P-N Transistor Unit : With a transistor mounted on base as described.

102.8 P-N-P Transistor Unit : With a transistor mounted on base as described.

102.9 Field Effect Transistor Unit : With a field effect transistor mounted on base as described.

102.10 Power Transistor Unit : Mounted on a base as described.

102.11 Diode Valve on Base : For experiments in diode characteristics, comprises a double-diode valve type EB91 (6AL5) or equivalent. The valve is housed in a standard box 90 x 90 x 35 mm provided with 4 mm sockets and screen printed panel diagram for identification of the valve electrodes.
Heater voltage 6.3 V maximum (to operate the diode under saturated conditions the heater voltage should be limited to 1.5 V approx.).
Anode current 5 mA maximum.
Anode voltage 150 V maximum.

102.12 Triode Valve on Base : For investigations into the behaviour of triode valves, showing ionisation and excitation potentials in different gases. Comprises a box, 90 x 90 x 35 mm, on the top panel of which are mounted an octal and a B7G valve holder. Connections for heater, cathode, grid and anode are provided and are brought out to colour-coded 4 mm sockets.

102.13 Thermistor : A bead-type thermistor mounted at the end of a 2-core flying lead, lenght 1 m, terminating in a pair of 4mm plugs. Resistance 800W at 0°C, 130W at 50°C. Max. Electrical rating 7 V or 1 A at 20°C.

102.14 Thyristor : For showing the basic principles of the thyristor as a power control device. It may also be shown how the switched mode operation provides a more efficient method of control than a rheostat or power transistor. Will switch voltages of upto 24V D.C. at a maximum load current of 4 A.

102.15 Multifunction Unit : Comprises two 'NOR' and one 'AND' gates interconnected. The functions of 'NOR', 'OR', 'NAND' or 'AND' gates may be investigated.

102.16 Traffic Lights : Comprises a row of three indicator lamps, red, amber and green, each provided with its own independent input socket.

102.17 Digital Electronics Units : Designed to the requirements of revised Nuffield 'A' level physics, these units are all based on CMOS integrated circuits. CMOS devices have advantages over TTL in that power requirements are lower so longer battery life can be expected, and the units will operate from any smoothed D.C. supply of between 4.5 and 9 V.
Whilst each board has independent power supply connections, they may be cascaded and run from a single power source. All the logic outputs are connected to L.E.D. indicators which are activated when the output goes high. Inputs are held low when not connected. All units are protected against damage from reversal power supply connections.

102.18 OP AMP Board : Incorporates a standard CMOS OP-AMP I.C., together with a range of passive feedback and input components to permit the ain etc. to be adjusted for both amplifying and operational purpose.
A pair of potentiometers allows selectable input voltage levels to be applied to the I.C., and offset-nul adjustment is also provided for input and feedback. Component selection is, as with the input,output and power supply terminations, via 4mm sockets on the board. External components can be connected if desired.

102.19 Astable Multivibrator and Electronic Switch : This board incorporates two of the units specified in the 'A' level list of requirements. Both functions being performed by a quad 2 input NOR integrated circuit. The astable multivibrator frequency may be varied over the range of about 0.5 Hz to 500 Hz, its output being taken to both an external output socket and an L.E.D. indicator via buffer transistor. The electronic switch may be used to provide an output which is high or low with a 'bounce-free' action. It has a buffered LED indicator in addition to its output termination.

102.20 Quadruple, Two Input NOR Gate : This unit comprises a single integrated circuit quad, two input NOR gate with each of its outputs connected to an indicating LED via a buffer transistor.

102.21 Quadruple, Two Input NAND Gate : This unit contains essentially the same circuitry as the NOR gate, GP-952.1, but is equipped with a quadruple two input NAND gate integrated circuit chip.

102.22 Dual RS Bistable Unit : This board carries a dual D type flip-flop integrated circuit providing both bistable functions. Each bistable has clear, set and clock input, together with Q and Q outputs. Buffered LED output indicators are also incorporated.

102.23 Logic Gates Tutor : Designed to cover all aspects of combinational logic and boolean algebra. Comprises a selection of AND, OR, NOT, NAND, NOR, EX-or and AND-OR-INVERT gates. Four logic input toggle switches and four logic indicators are also provided.

102.24 Sequential Logic Tutor LT2 : Provides facilities for the investigation of flip-flops, counters and shift registers. Comprises four jk flip-flops, five NAND gates and three logic input switches. One of the switch may be used to pulse counter circuits.

102.25 Patch Leads : Spare 1 mm leads for use with logic Tutors and Tutor kit units. Pack of 25.

102.26 OP-AMP Tutor OT1 : A versatile teaching aid which can be used to investigate many aspects of operational amplifier circuits. Apart from basic experiments it may also be used to generate wave form, solve mathematical equations and design active filters. The modue houses a 741 operational amplifier and a range of components and also provided is a 'free-area' which may be used to hold the users own components.

102.27 Power Supply Unit PSU1 : Designed for use specifically with the tutor kit units, but equally suitable for general purpose use, this unit provides a fixed output of 5 V D.C. at 1 A for TTL logic circuits and adjustable outputs at 15 V at 100 mA for op-amp and other linear applications.

102.28 I.C. Patch Board PB1 : A general purpose experimental and prototyping 'bread-board' module suitable for use with digital or linear devices and circuit. Comprises two 16-pin, two 18-pin and one 40-pin DIL sockets. The versatility of this unit is enhanced by the inclusion on the board of logic indicators, a two-speed clock, a manual pulser and logic input switches.

102.29 Combinational Logic Tutor : Very essential & vital training board in digital electronics lab for verification of truth table for various Logic gates. Student will make connections themselves with the help of interconnection leads and verify De-morgan's theorum and unravel mystery of boolean algebra. Standard 7400 series T.T.L. IC's are used Bounceless data switches and buffered LED indicators are also used.

Specifications
a) 2 Input AND Gates (IC used 74LS08) - 4 No.
b) 2 Input NAND Gates (IC used 74LS00) - 2 No.
c) 3 Input NAND Gates (IC used 74LS10) - 3 No.
d) 2 Input OR Gates (IC used 74LS32) - 4 No.
e) 1 Input NOT Gates (Logic Inverters, 74LS04) - 6 No.
f) 3 Input NOR Gates (IC used 74LS27) - 3 No.
g) 4 Bounceless Logic input switches with complementary outputs.
h) 4 Buffered LED Logic indicators.
i) Interconnection leads - 25 No.
j) Comprehensive User's manual - 1 No.

102.30 Sequential Logic Tutor : Various memory devices are incorporated in this model to study other fundamentals e.g. flip flops. Students can learn about synchronous and asynchronous circuits using various JK flip-flops & NAND gates. Manual and clock generated Input pulses are also provided.

Specifications
1. JK master slave flip-flops - 4 No.
2. Three input NAND gates - 6 No.
3. Logic Pulser (Manual) - 1 No.
4. Clock generator - Pulses of 1, 10, 100 Hz are provided on board.
5. LED indicators - Provided at output state of all flip-flops.
6. Pre-set & carry point of all flip-flops are provided with Logic input switches.
7. Bounceless Logic input switches - 4 No.
8. Solderless Patch leads - 25 No.
9. Comprehensive User's Manual - 1 No.

102.32 Logic Gates Trainer : It consists of specially designed brass socket of 2 mm inner diameter which are press fit by special techniques on bakelite panel. Complete functional diagram of each gate is engraved nicely so that the students can make interconnections themselves and verify the truth table. Hence they can realise Demorgan's theorum and boolean expressions. User's Manual for performing various experiments is provided with the instrument.

Features :
a) Regulated Power Supply of ± 5 V/0.5 Amp.
b) Logic Input Switches - 2 Nos.
c) 2-Input AND Gate - 1 No.
d) 2-Input OR Gate - 1 No.
e) 1-Input NOT Gate - 2 No.
f) 2-Input NAND Gate - 1 No.
g) 2-Input NOR Gate - 1 No.
h) LED Indicator - 1 No.

Features :
a) Solderless Breadboard with 1 terminal strip and 2 distribution strips.
b) Regulated Power Supply of ± 5/0.5
c) Logic Input Switches - 4 Nos.
d) LED Indicators - 4 Nos.
e) P-N Junction silicon Diodes - 2 Nos.
f) Two 1 KW and one 10 KW resistance.
g) One N-P-N transistor.
h) Interconnection leads - 4 no.
i) Hook up wire of 20 cm length - 10 No.

Features :
a) Regulated DC Power supply of 5 V/0.5 Amp.
b) 2-Input AND Gate - 4 No.
c) 2-Input OR Gate - 4 No.
d) 1-Input NOT Gate - 6 No.
e) 2-Input NAND Gates - 4 No.
f) 2-Input NOR Gates - 4 No.
g) 2-Input XOR Gate - 4 No.
h) Logic Input switches (Bounceless) - 8 No.
i) LED Indicators (Buffered) - 10 No.
j) Clock Generator of 1 Hz, 100 Hz & 1 KHz.
k) R-S Flip-Flop - 1 No.
l) D Flip-Flop - 1 No.
m) J.K. Flip-Flops - 2 No.
n) Specially designed Gold Plated IC base of 14 pin - 1 No.
o) Inter-connection leads - 10 Nos.

General (Components of Front Panel)
a) Quad 2-Input AND Gate
b) Quad 2-Input OR Gate
c) Hex Inverters (NOT Gate)
d) Quad 2-Input NAND Gate
e) Quad 2-Input NOR Gate
f) Quad 2-Input XOR Gate
g) One Shot
h) 8-Input Multiplexer
i) RS Flip-Flop
j) Dual Flip-Flop
k) Dual J-K Flip-Flop
l) Decade Counter
m) Binary Counter
n) Shift Register
o) 4P/Down Counter
p) 4-bit Binary Adder
q) 4-bit Magnitude Comparator
r) Priority Encoder
s) Seven Segment Display
t) Binary to 7 Segment Decoder
u) Seven segment display with decoder
v) Special IC Base of 14 Pin
w) Special IC Base of 16 Pin
x) Logic Input Switches (Bounceless) - 10 No.
y) LED Indicators (Buffered) - 10 No.

102.36 Set of 4 Electronic Trainer Panels :

(a) Semiconductor diode and applications : To examine Diode Characteristics, to test a diode; to examine the diode behaviour as a switch; half wave rectifier, full-wave rectifier, study the bridge type full wave rectifier. Zener regulated simple DC power supply, full wave rectifier with capacitor filter, to examine a zener DC voltage regulator.

(b) Bipolar transistor and applications : To test a transistor; to measure the lc/lb characteristics of a common emmiter transistor; to measure the common emmiter DC current gain, b. To examine the transistor switch and DC bias conductors of a common emmiter transistors amplifier; to examine the voltage amplification and the band-width of the amplifier.

(c) Operational amplifier : OP-Amp as a switch. OP-Amp as an amplifier; to examine the inverting amplifier; to observe the inverter; to examine the non-inverting amplifier.

(d) Logic Gate : To examine the invertor or the NOT gate, the AND gate, the OR gate, the NAND gate, the NOR gate, the XOR gate and their truth tables using TTL ICs.

The pannels are of size 28 cm x 20 cm fitted 4 mm dia sockets for easy connections. The circuit is able to withstand 30V DC. Each pannel is provided with manual in English.

A box of spare components for the four pannels is provided. Which includes 2 nos. of each of the following items. 

Diode	Bridge Rectifiers	Zener Diode	Transistor
OP-Amp	NOT Gate	AND Gate	OR Gate
XOR Gate	NAND Gate	TTL ICs

Accessories :
Universal Power Supply
0 to 30 V visible, 1 Amp
± 5 V, ± 12 V DC, 1 Amp
± 15 V AC

102.38 Electronic Kit Senior : This kit is designed keeping in view the requirement of todays student who is very enthusiest regarding electronic projects. with this kit, one can make number of electronic circuits such as decade counter, shift regisger, display, uses of various gates in differnt applications, flip-flops, application of various operational amplifiers etc. housed in a very rugged easy carry housing. It is self contained bit as it provides all the components required for performing experiments as per illustrations of the comprehensive manual.

102.39 Diode Characteristics Apparatus : It is designed to work on 230 volts A.C. with built in power supply, fitted with diode valve 6H6 on the front panel. Two meters are provided to read voltage and current. This apparatus is very useful for plotting the characteristic curve of a Diode valve. Instrument is built in painted steel box.

Output
H.T. : 0-250 volts at 25 mA continuously variable
L.T. : 6.3 volts A.C. built in rheostat for filament current control.

102.41 Triode Characteristics Apparatus : It is designed to ork on 230 volts A.C. with built in power supply, fitted with triode valve 6J5 on the front panel. One dual range meter is provided for HT volts/current and one for Bios volts.

Output :
H.T. : 0-300 volts D.C. at 30 mA continuously variable
Base : 0-15 volts D.C. at 5mA continuously variable (Floating)
L.T. : 6.3 Volts A.C.

102.42 Triode Characteristics Apparatus : Same as above (102.41) but with stabilized power supply.

102.43 L.V. Power Supply AC/DC : Suitable to provide 2 to 12 volts in step of 2 volts. Four 4mm socket terminals for AC and DC output separately with fuse and indicator in ventilated painted steel cabinet.

a) 4 Amp.
b) 5 Amp.

102.45 H.T. Power Supply Unit : Provides output 0 to 300 volts A.C./D.C. Continuously variable at 6 Amps with dual range voltmeter for AC/DC and double range for AC/DC ammeter of high quality output is provided at 4mm terminal separate for A.C./D.C. output ON/OFF switch, main indicator/overload Indicator built in, adjustable handle. The unit is enclosed in rugged steel cabinet well painted operation 220 V, 50 Hz detachable mains lead.

102.46 H.T. Power Supply Unit : Provides output H.T. 0-500 volts at 100 mA, L.T. 2.5 volts, 4.2 volts and 6.3 volts and 12.6 volts at 4 Amps. Bias supply 50-0-50 volts, floating with one meter for H.T. Volts AC and DC with overload and short circuit protection. The unit is housed in nicely painted metal case with carrying handle. Complete with mains switch, fuse, indicator lamp and main cable etc. Power required 220 Volts A.C. 50 Hz.

102.47 5 KV EHT Supply : Output 100 to 5 KV at 3 mA continuous. Fully floating EHT circuits suitable for operation of spart, counters, discharge tubes etc. Provided variable output upto 5 KV. The EHT circuit are fully floating so that certain experiments the positive or negative terminals may be safely connected to earth.
The EHT output are taken from 4mm sockets and displayed on a 0 to 5 KV meter. Also on the front panel are a mains switch and indicator lamp. The main fuse is mounted on the back panel. In a robust metal case with feet, mains cable fitted by moulded connector. Cable and connector removable for storage. Workable on 220V 50 Hz.

102.48 L.T. Power Supply Unit : Provides output 0-50 volts D.C. At 4 Amp, with dual range voltmeter for AC/DC and double range for AC/DC ammeter of high quality output is provided at 4 mm terminal separate for A.C./D.C. output ON/OFF switch, main indicator/overload indicator built in, adjustable handle. The unit is enclosed in rugged steel cabinet well painted operation 220 V, 50 Hz detachable mains lead.

102.49 L.T. Power Supply Unit (D.C. Power Supply) : Provides output 0-15 volts D.C. At 1 Amp. ± 10% A.C. line variation and noise less than 2 mV RMS with 2 meters with overload and short circuit protection. The unit is housed in nicely painted metal case with carrying handle. Complete with main switch, fuse, indicator lamp and main cable etc. Power require 220 volts A.C. Hz.

102.50 A.C./D.C. Power Supply Unit : Provides output 0-20 volts D.C. And 0-25 volts A.C. continuously variable at 10 Amps. With dual scale. Deluxe meter to read volts AC/DC. Output is provided at 4 mm socket terminals separate for A.C. and D.C. ON/OFF switch, indicator and two output safety fuse. The unit is enclosed in ventilated steel painted cabinet.

102.51 A.C./D.C. Power Supply Unit : Same as above (102.50) but output 0-25 volts. A.C. and 20 volts D.C. at 5 Amps.

102.52 Multi Tap Transformer : Voltage output 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12 V A.C. selectable from 2, 4, 6, 8, 12 volts tappings. Current output 6A continuous, 8A maximum upto 1 hour. Output is taken from central common and indivisual 2, 4, 6, 8, 12 volts AC sockets. Also mounted on the front panel are a mains switch, indicator lamp and fuse. In robust metal case 250 x 160 x 110 mm high with mains cable fitted by moulded connector.

102.53 Signal Generator, 1 Hz to 100 KHz : Sine, square and triangular waveform short circuit protection. High input impedance amplifier. Output 0-20 volts pk-pk at 50 ohms.
A high power, robust, wide range signal generator providing sine, square and triangular waveforms. An instrument designed for a wide range of applications, with clear front panel layout for easy use.

Technical Data
Frequency range 1 Hz to 100 KHz in five decades and read on linearly calibrated scale.
Accuracy ± 2% on all ranges.
Output sine, square and triangular waveforms.
Amplitude control continuously variable from zero to maximum output.
Attenuator 0.2, 2, 20 Volts.

Output Frequency Range Output : 1 Hz to 110 KHz. 5 switched ranges. Sine, Triangular and Square waveforms.
Outputs : High impedance with 600 ohms constant impedance attenuator.
Low Impedance : Both outputs paired colour coded 4 mm sockets at 19 mm pitch. power 6 W rms into 8 ohms at low impedance output.
Maximum Output : Voltage 14 volts pk-pk typical at high impedance output. Rise time of square wave 1 ms (both outputs). All outputs are fully floating and short circuit proof.
Input : Pair of colour coded 4 mm sockets and coaxial socket. Amplifier input impedance 1 Mohm.
Attenuator : 0-20 dB with constant impedance at 600 ohms output.
Controls : Mains switch on amplitude control.
Frequency Control Dial : Range selection 5 positions switch. Attenuator three position switch.
Electrical Protection : Internal 20 mm fuse.