PS 723 = NTE 923 George Afana Electronics Moreno Valley, CA grndmstrg@xxxxxxxxxxxx ----- Original Message ----- From: "George" <grndmstrg@xxxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Friday, August 01, 2003 8:09 AM Subject: [TechAssist] Re: Home made variable DC Power Supply > Warren, > > That IC is most likely a 723 (Ex: uA723) came in T03 can and DIP and was > made by several semiconductor companies. This IC was popular about 20-25 > years ago. Adjustable from 1.2 to 37 volts at about 150-200 ma or so. The > series bypass transistor provides the higher ampere current capacity and has > current limiting. I built several power supplies using this IC with good > results. > > George > Afana Electronics > Moreno Valley, CA > grndmstrg@xxxxxxxxxxxx > > ----- Original Message ----- > From: "Warren C." <warrenca@xxxxxxxxx> > To: "techassist" <techassist@xxxxxxxxxxxxx> > Sent: Thursday, July 31, 2003 9:52 PM > Subject: [TechAssist] Home made variable DC Power Supply > > > > Hi All > > > > My old DC PS finally Quit regulating, problem is it was built so many > > years ago > > that I no longer have the schem. > > It controls the Voltage output from 35 V down to about 1.5V > > The current can be adjusted from 2A down to about 5ma. > > > > I've found some bad caps and replaced them but it still does not > > regulate down below > > 10 V and it used to. > > The main problem (I think) is the reg. IC# is IC321 and I can't find it > > or cross it. > > It is a 5/16" can type with 8 legs on it. The IC controls a large heat > > sinked T O 3 trans. > > > > Does anyone have info on this IC?? > > I would welcome your schematics for similar home made PS's > > > > Secondly where in Canada can I buy a ESR cap tester. No insult but I > > had a bad experience > > years ago with an electronics company in the States. I sent down a mail > > order for about $350.00 > > It was cashed but never received any thing for it and no replies > > afterwards..! > > > > TIA > > > > Warren Campbell > > Campbell's TV & Appliances > > Cannington On > > Canada > > > > > **************************************************************************** > * > > Classifieds! Buy or Sell! > > http://sell.tech-assist.org > > The Tech Address Book: > > http://www.tech-assist.org/secure/tip/contact.htm > > Add a Repair Tip Here, or Change/Remove your Email Address: > > http://www.tech-assist.org/secure/tip/main.htm > > Lost Password: > > http://www.tech-assist.org and select "Lost your Login Info?". > > Email Archives: > > //www.freelists.org/archives/techassist/ > > > > > **************************************************************************** * > Classifieds! Buy or Sell! > http://sell.tech-assist.org > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.htm > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ > ***************************************************************************** Classifieds! Buy or Sell! http://sell.tech-assist.org The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.htm Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". Email Archives: //www.freelists.org/archives/techassist/