Chopper drive circuits Chopper drive circuits are also referred to as constant current drives because they generate a somewhat constant current in each winding rather than applying a constant voltage. On each new step, a very high voltage is applied to the winding initially. This causes the current in the winding to rise quickly since [...]

Short notes about Circuit troubleshooting. – Check the circuit for mechanical failures, like disconnected wire, broken vias on the board, and connections between two adjacent vias which are not to be connected. – You should compare values of components and their connections with values and connections between components on the schematic. – Measuring DC voltages [...]

The Light Emitting Diode (LED), finds its place in many applications in this modern electronic fields. One of them is the Seven Segment Display. Seven-segment displays contains the arrangement of the LEDs in “Eight” (8) passion, and a Dot (.) with a common electrode, lead (Anode or Cathode). The purpose of arranging it in that [...]

Applications: In monitoring & controlling of power systems such as Transformers, Generators, Motors etc. To analyze the performance of electrical machines. Can be used as a safety device to protect machines from over loading, excessive voltage etc. To make the power distribution system efficient. Recording device/Line parameters. Introduction This unit is used to protect heavy [...]

GSM – AN OVERVIEW GSM, Global System for Mobile communications, is today the most successful digital mobile telecommunication system. This second-generation (2G) system provides voice and limited data services and uses digital modulation with improved audio quality. The different versions of GSM are: GSM 900 band (850-915MHz up-link frequency and 935-960MHz downlink frequency) GSM 1800 [...]

GPS – AN OVERVIEW The GPS (Global Positioning System) is a “constellation” of 24 well-spaced satellites that orbit the earth and make it possible for people with ground receivers to pinpoint their geographic location. The location accuracy is anywhere from 100 to 10 meters for most equipment. Accuracy can be pinpointed to within 1 meter [...]

The RF section consists of an RF transmitter and an RF receiver.  The RF transmitter mainly consists of a remote key that contains a code hopping encoder, HCS301 along with 2 buttons and two LEDs. The RF receiver section consists of a Low Power ASK receiver IC. The key encoder will generate the company specific [...]

The term PIC, or Peripheral Interface Controller, has been coined by Microchip technology to identify its single chip microcontrollers. PIC microcontrollers possess an array of features that make them attractive for a wide range of applications. Furthermore these microcontrollers are available with a range of capabilities, packaged in both dual-in-line(DIP) packages and surface-mount packages. Factors [...]

The Light Emitting Diode (LED), finds its place in many applications in this modern electronic fields. One of them is the Seven Segment Display. Seven-segment displays contains the arrangement of the LEDs in “Eight” (8) passion, and a Dot (.) with a common electrode, lead (Anode or Cathode).

There are four ports P0, P1, P2  and  P3 each  use  8 pins,  making  them 8-bit  ports. All the ports upon  RESET are configured as output, ready to be used as output ports. To use any of these ports as an input port, it must be programmed. Pin configuration of 8051/8031 microcontroller. Port 0: Port [...]