Jean-Paul, Accepted. That is very true and I don't use the -5 or the + and =20 -12 very often any more. But you have to understand that I built this=20 supply more than 20 years ago and 741s are still good for some quick and=20 dirty circuits. I am also very limited when it comes to disposable income. SSD=20 doesn't go very far. The adjustable supply is very useful for testing=20 different types of test circuits. It gives me from just under 3 volts to=20 over 30 volts. If you look at the picture you will see a white wire=20 sticking up in the air. That is a 35 volt ac line. So I actually have=20 six different busses available coming off of three different=20 transformers. The supply is very flexible which is what I wanted. It has=20 also been very reliable, especially when you consider that it is all=20 built from used parts. Once in a while I have to replace the main filter=20 caps. Thanks, rich! On 7/25/2014 11:43 AM, Jean-Paul Louis wrote: > Richard, > I did not mean disrespect, my surprise was at the need for 4 dual rail po= wer supplies. > > With the technology available now, you can do with a single rail even for= analog signals. > A lot of op amps now can run rail to rail output with 5V or even 3.3V. > I suppose your project has more stuff than just a counter and display. > Unless you really need a DC component on your measurements, a single rail= op amp with AC coupling and bias at midpoint will do the job. > > Jean-Paul > AC9GH > > > On Jul 25, 2014, at 12:07 PM, Richard R. Pope wr= ote: > >> Jean-Paul, >> Thanks, for the complement. Please watch the language. The pictures >> are posted here: >> https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/147414244 >> Because I do circuit designs with op-amps. >> rich! >> >> On 7/25/2014 10:59 AM, Jean-Paul Louis wrote: >> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .