Ummm, turn the regulator upside down?, is there any provision on top, or you have to cut the legs, and put them on the top |^^^|^^^|. plz be more specific with this. The idea of the zener diode is great, I think,.. Yesterday looking for a 9.1v zener, I found 2 on the s video input of a sony board, with 2 cathodes, never saw any of those before, but in the Sam schematic they are like regular diodes.?? pete Miami,Fl E-mail message Sender: techassist-bounce@xxxxxxxxxxxxx From: pbader@xxxxxxxxxxxxxxx(Philip=A0Bader) Date: Fri, Dec 30, 2005, 11:16am To: techassist@xxxxxxxxxxxxx Subject: [TechAssist] Re: good sub 78m05a Reply=A0to: techassist@xxxxxxxxxxxxx And that ground leg zener trick opens up a way to make a variable regulated DC power supply source.I imagine with a pot in the ground leg,or some such arrangement? Now, if you need a negative polarity output from a positive output reg IC,just turn the reg upside down. ;-) Phil Philip Bader Polk County School Board Electronics Shop Bartow,Fl. (former owner, Jan Phyl TV INc., Winter Haven, Fl. from 1976-2006) email: pbader@xxxxxxxxxxxxxxx ----- Original Message ----- From: "Gary McCartney" <gary@xxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Friday, December 30, 2005 11:11 AM Subject: [TechAssist] Re: good sub 78m05a Yes, certainly a 78M05 can be subbed with a 7805. 78M05 is rated 0.5 amps and a 7805 is rated 1 Amp. There is no reason to even stock the 78M05, just have a few 7805's on hand. Same goes for any other regulator in the family- 7812, 7808, etc. Generally speaking, over the years reading these tech emails, I am amazed at the lack of knowlege about these IC's, they are basic fundamental electronic components like a diode or a transistor. Any reasonings? --Did you know that you can raise the output voltage of a 78xx series regulator, by inserting a zener diode from the ground pin of the IC to ground? If you want an 8V regulator but only have a 5V regulator 7805 in stock, you can insert a 3V zener from pin 2 of the reg to ground and get an 8V reg. (as long as the back plane of the regulator IC is not connected to ground itself because it is common with pin 2, unless of course we are talking about a plastic backed IC) Gary McCartney McCartney Electronics Guelph Ontario Canada Est. 1984 email: gary (at) number63.ca pete wrote: can i use a 7805a to sub a 78m05a anyone has done this before? its a 5 volt regulator from a sony power supply model is kv35v35 Perdomo Tv Inc Since 1972 Miami.Fl ---------------------------------------------- This Email List is accessible to the general public through search engines. Remove: http://www.tech-assist.org/remove.htm Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=3Dset%20techassist%20vacation Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: http://www.freelists.org/archives/techassist/ ---------------------------------------------- This Email List is accessible to the general public through search engines. Remove: http://www.tech-assist.org/remove.htm Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=3Dset%20techassist%20vacation Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: http://www.freelists.org/archives/techassist/ ---------------------------------------------- This Email List is accessible to the general public through search engines. Remove: http://www.tech-assist.org/remove.htm Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=3Dset%20techassist%20vacation Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: http://www.freelists.org/archives/techassist/ ----------------------------------------------------------------------------- This Email List is accessible to the general public through search engines. Remove: http://www.tech-assist.org/remove.htm Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: http://www.freelists.org/archives/techassist/