comp wont start unluess I unplug / replug it into the wall

[malagash]

running win 2k fully updated and scanned for everything on an ibm P3 866mhz, 256 meg.
computer won't start unluess I unplug / replug it into the wall. I get the "operting system not found" message.
when i unplug it and reinsert the power cord to the wall it starts normally...
TIA

 

[DTracy]

An SCR has only two states when used with straight line DC and that is full on or full off. When used with ocillating DC (square wave) or AC the output is variable much as a TRIAC but with polaized results such as a diode. The SCR was used with DC as a gated switch and with AC as a lightduty variable speed controller for AC/DC motors. I have used it myself in both applications.

Whether an SCR or TRIAC is applicible in this case is unknown to me.

Regards,
David.

 

[LawnBoy]

much as a TRIAC but with polaized results

Polarized, as in one direction only, as in Direct Current.

Ok, this is a dead horse and I'll stop beating it now, Greg.

 

[CobolKid]

I'll beat it one more time.

LawnBoy,

The definition of a diode is an electrical device that allows current to move through it in one direction with far greater ease than in the other. A forward biased diode allows current to pass through with some (usually minor) loss, a reverse-biased diode prevents current from passing through, however a very small amount of current can and does pass through. This current is called the leakage current.

Now, a diode, and a gated diode (scr) does what? Both allow electron flow in one direction and for the most part block electron flow in the opposite direction. Additionally, a gated diode has a "trigger." Both function with electron flow in both directions;
function 1 == allow,
function 2 == block.

Yes, it is a polarized junction, it only passes electrons in one direction, or direct current, but the device is intended to operate in an alternating current environment. That makes it an A.C. device.

I DID NOT mean triac. A triac actually consists of two gated junctions that share a common bond, and triacs have their own particular characteristics, which are close, but different than two scr’s wired back to back. An alternistor consists of two scr’s wired back to back in a common housing.

DTracy; A triac is not required in the application I described, because the need is to conduct in one direction only. One could argue that a triac could be used at that point to provide reverse polarity protection, however that is accomplished in a simpler and more economical fashion by the use of diodes as clamps.



Steve