RE: Hot Swappable Power Supplies ?

2001-06-20 Thread Richardson, William G
There must be a bleeder resistor (across the X caps) to make the AC input pins safe to touch once the supply is removed from the cabinet. If there are exposed voltage or energy hazards with the supply removed, there must be a restriction such that only trained personnel are instructed to do this

RE: AC Power Primer?

2001-05-04 Thread Richardson, William G
The important thing to note is that a good amount of the utility load is not constant power. It is light bulbs, toasters, coffeemakers, hairdryers and electric heaters and so on. So lowering the voltage 10 % is the first step - the so-called brown-outs. Power is a square function, so the new pow

FW: Do not dial 9, 0, #, then hang up when requested.

2001-03-19 Thread Richardson, William G
It may sound like an Urban Legend, but it has a basis in fact. It only applies to some PBX systems where you dial 9 to get an outside line. http://www.att.com/features/0398/90pound.html Bill Richardson Unisys Corp. -Original Message- From: Jacob Schanker [mailto:j.schan...@worldnet.

RE: Ce versus FCC

1998-07-07 Thread Richardson, William G
Typically, the range switch on the cost-sensitive (cheap) power supplies changes the front-end topology from conventional capacitor input to a voltage -doubled one. Since the power load stays the same, the current will double. But the nature of the input current to these supplies is gulps of cur