I'm glad to hear that Tom will replace the unit for you. I've worked with Asian multivoltage switching supplies for years, and what the manufacturer usually won't tell you is that their primary output (usually the +5) of a multivoltage PS needs at least a 10 - 20 percent (or so) minimum load in order for the whole unit to meet spec and be stable. I would never leave one of these operating unloaded for any length of time... The result is usually what you saw, or a secondary voltage that goes way out of spec and burns out the attached device or itself. I usually just tag an appropriate 5 watt cement resistor on this particular output just to be safe, even though I contribute 2 more watts to global warming.
This is not just an issue with Asian supplies, either. One of my favorite domestic supplies (from Red Rocket/EOS) has such a restraint, only they tell you about it explicitly in the specification. I have one of my EOS units going on my Tbolt, as I hear I will be a proud owner soon. The EOS units are whisper-quiet and are about the size of a RAZR cell phone. -Dave Date: Thu, 11 Sep 2008 06:06:34 -0400 From: [EMAIL PROTECTED] Subject: Re: [time-nuts] Trimble GPSDO power suply unit. To: [email protected] Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii"; format=flowed My Trimble GPSDO just arrive but I have a problem with the POWER Supply Unit. After connecting all wires to the Trimble plug and made a check if all voltage is correct and left the PS unit to run on the table without load/connecting to the GPSDO, about 15min got a big bang and the Power Supply Unit blow-up. Opening the box found Q1 transistor / BUZ78 / blown and seems to me that it was a short around R1, R2 and C11 area, namely the two resistor had short to each-other...../ factory bad installation??? / Anybody having a circuit diagram ????? I am trying to repair..... Please help, I just do not want to throw the unit to the garbage can. _____________________________________________________________ Are you a Techie? Get Your Free Tech Email Address Now! Visit http://www.TechEmail.com _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
