Showing posts with label Discrete-Passive. Show all posts
Showing posts with label Discrete-Passive. Show all posts

Monday, September 15, 2014

Circuits using only discrete devices

Here are circuits made of Resistors, Capacitors and Inductors which are passive components. Crystals, Thermistors, Varistors, Variable Passive RLC are also Passive Parts.

Circuits using only discrete devices

Zeners, Diodes, NPN-PNP Transistors, FET, MOSFET, SCR, Triacs are all discrete active devices. ICs and Hybrid Modules are made of many discrete and passive components. In the Integrated Circuits or ASICs, all parts even passives are derived on the Silicon Wafer. In Hybrid Modules the construction uses SMD or Tiny Chip components interconnected in a small ceramic PCB and Hermetically Sealed if needed.

Parts or Components in Electronics

Parts like Switches, Connectors, Relays and PCBs are ElectroMechanical parts. Nuts, Bolts, Screws, Cabinets and enclosures are Mechanical parts.

For a Systems Integrator or Control Panel Designer, the Timers, Controllers, PLC which are Electronic Products become Components or Modules along with Contacters, Current Transformers, AC-DC Drives etc.

Tuesday, April 22, 2014

Reliability in Axial and Radial Plastic Capacitors

The Axial capacitors like Metalized Polypropylene MPP are more reliable in comparison of their radial counterparts of same voltage rating.

Also note 440V AC Continuous rating reads and translates differently than 630V DC Max. Overrating is an important step in reliability for engineers.

High Energy Circuits

Radial plastic caps, in mass production, due to various inconsistencies in production or quality measurement, are not recommended for high voltage unless its is a Manufacturer known for long term reliability and quality track record.

Reliability in Axial and Radial Plastic Capacitors

The radial caps when being wound, stretches the film/dielectric or weakens the dielectric at some areas as the turn is sharp, top/bot. This is possible unless the winding machine relaxes strain around the turns. In a Axial that may not be a problem as the film has more uniform stretch. The other reason could be that the Film is wrapped a little on corners or compressed on epoxy impregnation. It could also be low quality non-uniform PP material.

Power Electronics & Solar Energy

Components Manufacturers have to spruce up a Raw-Material and Component Quality, not by red-tape but by actually improving the manufacturing and procurement processes, as the quantities involved are huge.