Sivananda Electronics Lam Road, Nashik, Maharashtra

LM358 BASED HEART BEAT SENSOR CIRCUIT: Heart beat is sensed by using a high intensity type LED and LDR. The finger is placed between the LED and LDR. As Sensor a photo diode or a photo transistor can be used. The skin may be illuminated with visible (red) using transmitted or reflected light for detection. The very small changes in reflectivity or in transmittance caused by the varying blood content of human tissue are almost invisible. Various noise sources may produce disturbance signals with amplitudes equal or even higher than the amplitude of the pulse signal. Valid pulse measurement therefore requires extensive preprocessing of the raw signal. The new signal processing approach presented here combines analog and digital signal processing in a way that both parts can be kept simple but in combination are very effective in suppressing disturbance signals. The setup described here uses a red LED for transmitted light illumination and a LDR as detector. With only slight changes in the preamplifier circuit the same hardware and software could be used with other illumination and detection concepts. The detectors photo current (AC Part) is converted to voltage and amplified by an operational amplifier (LM358). Output is given to another non-inverting input of the same LM358; here the second amplification is done. The value is preset in the inverting input, the amplified value is compared with preset value if any abnormal condition occurs it will generate an interrupt to the controller.

The Component Comparator Model LCO - 2 is specially designed for high speed sorting of resist ors, capacitors and inductors. The equipment is equally suitable for both component manufacturers and bulk consumers for production, inward inspection and quality assurance testing requirements. The Model LCO - 2 uses a low level, 1 KHz test signal and brid ge principle for measuring percentage deviation. In addition to percentage deviation a phase detector is used to measure tand for capacitors. Four ranges of 1%, 2.5%, 10% & 20% FSD for deviation and single range of 1% (0.01) FSD for tand is provided. The e lectronic go - no go system is the regular features of model LCO - 2. These features makes it a versatile, high speed component comparator. A speed of 1500 pieces per hour even by unskilled operator is normal. The equipment is immune to short circuits, wrong selection of ranges, voltage fluctuation and mishandling which is likely to occur during use by unskilled operator.

Digital Conductivity Meter Portable Conductivity Meter has been developed to facilitate easy determination of conductivity of non-ferrous metals based on eddy current principle. Instrument uses a probe which when placed on the surface of metal indicates conductivity on a linear scale panel meter. The instrument can be used to measure stressed conditions if they can be related to the electrical conductivity of the specimen. Whilst the accuracy claimed is 2% however, for high conductivity samples as accuracy of better than 1% is easily obtained. The users can also, if desired, use their own sample of known conductivity in the region of interest to enhance the accuracy. The instrument is supplied in a rugged carrying case which gives complete protection and has separate pocket for probe. The equipment can be used without removing it from the carrying case

Features of ATMEL AT89S52 Starter Kit: AT89S52 40 PIN DIP 16 X 2 ALPHANUMERIC LCD ON BOARD RTC 1307 ON BOARD EEPROM 24CXX ON BOARD ADC, MAX232 FOR RS232 SERIAL PORT COMMUNICATION 10 PIN IN-SYSTEM PROGRAMMING (ISP) CONNECTOR 4 PUSH PULL SWITCHES 2-BC547 TRANSISTORS. MCP3201 ADC UL2003 FOR STEPPER MOTDC MOTOR L293 FOR ROBOTIC APPLICATION ON BOARD REGULATED POWER SUPPLY RESET SWITCH 11.0592 MHZ CRYSTAL BELOW IC