"Dennis Monticelli" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- It appears to me that your PS has an undervoltage lockout feature. This is relatively common in today's supplies, but not so when the PS7 was built. Undervoltage lockout turns off the output when the input voltage is insufficient for the PS to work correctly. An incorrectly working supply is potentially dangerous to the load because the output voltage may actually go to a high output state (excessive output voltage) or oscillate. During PS startup, there is special circuitry to insure that the PS is able to ramp itself up rather than get trapped in the undervoltage lockout state. My guess is that the startup circuity in the PS7 is rate sensitive. When you apply full AC instantly, it starts up. When you apply AC input slowly, it does not. Rate sensitive startup (using a capacitor) is usually cheaper to implement than using logic to govern startup.
I don't have a PS7 schematic so I admit to some speculation regarding your problem. Dennis AE6C On 3/23/06, Ron Wagner <[EMAIL PROTECTED]> wrote: > > Ron Wagner <[EMAIL PROTECTED]> made an utterance to the drakelist gang > ---------------------------------------------------------------------- > Kevin, > If I understand you correctly, you were only feeding a percentage of the > design voltage to the PS7 because of the variac. > > Let me make a guess as to your problem. The regulator board needs a > specified minimum voltage to run correctly. If you were in fact > "starving" the regulator of the correct operating voltage, anything is > possible. Anything including the distruction of various components within > the regu;lator board, feedback loops in the regulator oscilating, and any > number of other strange things. > > So my guess would be the 723 had its "boxers in a bunch" and did whatever > it pleased and did not get reset until voltages got within specs for the > design. > > 73, > Ron > ---------------------------------------------------------------------- > Submissions: [email protected] > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > ---------------------------------------------------------------------- > ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
