Pulse Width Modulation and Demodulation

Mounted on transparent covered box. Diagram provide with three different color four mm sockets for easy identification of terminals.

A common anode seven segment module is fitted on a board with 8 bit dip switch to control the each segment of seven segment LED display. The inputs A-D of a display driver are connected to the binary coded decimal (BCD) outputs from a decade counter. A network of logic gates inside the display driver makes its outputs a-g become high or low as appropriate to light the required segments a-g of a seven segment display. A resistor is required in series with each segment to protect the LEDs

Complete with Regulated power supply of + 5V/500 mA. Provided with 4 Logic input switches (bounceless) 4 LED Indicators (Buffered) Functional diagram of :- 1. 3 Input NAND – 6 No. 2. 4 Input NAND – 4 No. 3. 1 Input NOT Gates – 4 No. is printed on board. 4. 12 Interconnection Leads and User’s Manual is provided.

Objective: To construct an optical transmitter and transmission of signal through Fiber Optics Cable. To construct an Optical Receiver and study the Attenuation of Signal when transmitted from Transmitter to Receiver end. Analog and Digital link can also be studied as this unit is complete with Sine and Square Waves. Bending losses can also be studied. Features: Instrument comprises of Microphone Preamplifier stages consists of MIC (Microphone), Preamplifier and Amplifier (Voice is converted to electrical signal and then amplified) and fed to LED (Transmitter) and then through fibre cable, signal is sent to Photodetector (Transistor) and again amplifier and output is sent to Speaker Unit. Power Supply of +6 VDC is used in Amplifier ckt. 2 No. Fiber Optics cables are provided (one of them is 50 cm long and the other is 100 cm long). One more fiber cable of 50mm length having connector at one end is also provided. Connectors a both end of fiber cable are provided for insertion in sockets provided on the front panel. Bending losses can also be studied in long wire. Standard: MIC with 2 meter long lead and a Speaker 4”, 4 ohm are mounted in a vertical box. Accuracy: with 1 meter long connecting leads. 2 No. Fiber optic cable having length of 50 cm and 100 cm are provided. Optional : Digital multimeter (3 1/2 Digit, Big size Display) This model also include Digital Multimeter and wooden frame for measurement of Numerical aperture i.e. complete in all respect including facility for measurement of numerical aperture.