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Showing posts with the label LM393

Universal logic probe

These days good quality oscilloscope is not an expensive instrument and, we can see it in most workbenches. With the advancement of oscilloscopes, simple testing tools such as logic probes are not as popular these days. However, if the oscilloscope or logic analyzer was out of reach, the logic probe is a handy instrument to check digital circuits.  Also, in some cases, a logic probe is an easy option to check the functionality of low-speed logic circuits because it provides a real-time visual indication of the logic state without adjustments or calibrations. Prototype version of the logic probe. The logic probe design described in this post uses common and inexpensive ICs, including the popular NE555 timer and LM393 low voltage comparator IC. At the time of this writing, both ICs were prevalent in the market and cost less than LKR50 (US$ 0.25). This circuit design using SMD components to minimize the board size. The dimensions of the soldered PCB are around 70mm × 14mm × 6.6mm, ...

Low cost Carbon Monoxide meter

Today Carbon Monoxide ( CO ) meters are available in different forms. Overall, Carbon Monoxide meters sense CO fast and display the amount to the user and trigger alarm if it reaches a critical level. Compare with most of the DIY Carbon Monoxide meters, the project which we described in this article does not need any development platform or MCU / firmware. The Carbon Monoxide meter in this project design around using general-purpose ICs, such as NE556 and LM3914 . Prototype version of Carbon Monoxide meter The main component of this meter is the FC-22 CO Gas sensor module . This module consists of the MQ-7 sensor and can use to detect CO gas concentrations, anywhere from 10 to 10,000ppm. Apart from the sensor, this module consists of the LM393 comparator to detect the trigger level. In this design, we use both analog and digital output of the sensor module. The analog output use by the LM3914 LED driver and alarm system is drive using the digital output. Home made PCB with align...

Electric Fence with Automated Monitoring System

Electric Fences are designed to create an electrical circuit when touched by person (or animal). The circuits proposed in this article release 10kV electrical pulses to the fence-line and monitor the line status. This entire system is design to drive using 25V (5A) single-rail DC power source (using 5A power supply unit or pair of 12.6V Lead-Acid batteries). Main controller of this system is Microchip PIC12F675 – 8bit microcontroller. All the line monitoring, pulse generation and alarm system controlling is performed by this microcontroller. Some of the most notable features of this system are built-in audible alarm system, contactless fence line monitoring system, Support for wide range of step-up transformers (up to maximum of 10kV) and compact 10cm × 10cm PCB design. This system use standard electronic components (through-hole components) and SMD components in this provided PCB layout. All the project documents, schematics, PCB designs and firmware source codes are available...