On Mar 17, 2009, at 9:50 PM, Ernest L. Gunerius wrote:
> >> Hi Jeff, >> I have been in the electronic service business since 1954 & in my >> judgment, you should buy a Volt-ohm-milliamp meter & learn how to >> use it. >> It will be a lot more versatile. >> Regards Wm. >> >> >> --- On Tue, 3/17/09, MacGuy <[email protected]> wrote: >> >>> From: MacGuy <[email protected]> >>> Subject: Power supply tester >>> To: [email protected] >>> Date: Tuesday, March 17, 2009, 9:29 PM >>> Would this little guy work for Apple OEM power supplies? and >>> if not, >>> anybody seen one out there for macs? >>> >>> http://www.directron.com/pst03.html#caption >>> >>> Jeff Engle >>> Kamiah Idaho 83536 >>> > > Hi Jeff; > > I agree with Wm. > I spent many years designing, building and testing power supplies. I > have designed and built several power supply testers. Since the > 1950's also. From a 12KW Supply for a Vacuum Tube Room Size Computer > to small on PC Board single voltage supply to power one Dual in-line > Logic chip. > > For general trouble-shooting a Volt-Ohm-Ammeter / Milliamp meter is > the most economical approach. The device shown in the Web-Link seems > to be only a Connector, Case and a switch to select which outputs to > read. They do not say at what current load the power supply is > tested; it is probably set to be just enough to ensure stable > operation of an ATX Supply in good condition. If the Power Supply is > tested installed. I don't see that as being switchable in the picture. > > If all you want to know is : "Does it work?" a Volt Ohm Meter is > adequate since you would be testing with the Power Supple installed > and loaded by the Computer circuity at the load for all outputs set > at the normal for that Computer. In that case: "Does the fan run or > the Lights light?" > > No one fixes computer power supplies and if they did a more complete > line of Instruments would be needed. You would be looking at > thousands of dollars. > > If you are testing a stand alone power supply you will need to know > if it is spec'ed to run at no load on all outputs or if not you will > need to know what loads on what outputs will guarantee proper > operation. This applies to all some Switch Mode Topologies but not > all. Linear supplies are another story. > > On stand alone's a variable AC Transformer might be helpful. You can > gradually increase the input AC to avoid nasty smoke and exploding > Capacitors. > > Spring Clips to Banana Plug test leads long enough to reach into the > computer from the meter can help avoid slipping test prods that can > really ruin your day. > > I hope this is not to confusing. It's past my bed time. > HTH, > ErnieG > > > The one thing I've always liked about you, Ernie, is that I always get a "complete" answer to my questions. Thanks:-) Jeff --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
