delabs Technologies News

These are Electro Mechanical Points which i noted from my past experience, in my Amps-n-Volts Newsletter.

• The tracks or components on a PCB should not be near the mounting holes, the tracks may form electrical connections with the cabinet earth if they touch the pillar, washer or nut-bolt.
• When you tighten the screws-nuts-bolt limit torque by feeling or with torque limit screwdrivers, or thread will slip or PCB-Cabinet break, or CRT-Glass-Plastic will crack-shatter.
• After assembly and testing is over on a board, do not drill-file it, it should have been done before. Else components crack or tracks break or small metal pieces will form shorts.
• The Mechanical and electro-mechanical must be streamlined before production, for example when fitting the board the screwdriver may slip and break a zener. The product should be engineered in such a way that it fits easily and the testing and quality checks need not be repeated.
• Some mechanical failures may not be visible but may show up as a field failure after even 3 months. this will make you lose further orders and ruin the reputation. Hence design engineering is vital.
• Sparking at the high voltage mains supply power contacts like a plug can cause electronic gadgets to fail. When you drive nails into walls ensure that that part of the wall is free of mains, telephone or any wiring.
• Some pcbs can have hairline cuts or hairline shorts which will make troubleshooting difficult.
• Never ‘put or remove’ ICs, cards or plug-in modules when the power to that system is on, power off system wait for some time for caps to discharge, then insert ICs or cards, applies to PCs too, USB and Firewire ports are exceptions as they are hotplug, anyway even in this, take a bit of care as some peripherals may cause some problems.
• Teflon tape can be used to make leak proof pneumatic or hydraulic connections if junctions are leaking.