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Electronics => Beginners => Topic started by: MAntunes on November 30, 2015, 06:47:24 pm

Title: Getting symetrical voltages from single suppley for opamps
Post by: MAntunes on November 30, 2015, 06:47:24 pm
Hello, my name is Miguel and I am from Portugal. Sorry in advance for my english.
I was looking for the best way to get symetrical voltages from one single voltage to bias op amps. Getting -/+5V with a 10 or 12V supply for example.
First I thought of a voltage divider, with just two resistors. But than I realized that it could became instable.
Then it came to my mind that I could use linear regulators like 78xx and 79xx.
Can you help me in finding the best way?
Thank you in advance for your help.

Miguel
Title: Re: Getting symetrical voltages from single suppley for opamps
Post by: max666 on November 30, 2015, 07:00:54 pm
I don't know about the best one, but this might be a good start http://tangentsoft.net/elec/vgrounds.html (http://tangentsoft.net/elec/vgrounds.html)
(http://i.imgur.com/cp2sXeG.png) (http://tangentsoft.net/elec/vgrounds.html)[Sauce (http://tangentsoft.net/elec/vgrounds.html)]
Title: Re: Getting symetrical voltages from single suppley for opamps
Post by: 0xdeadbeef on November 30, 2015, 07:05:36 pm
http://www.circuitstoday.com/dual-power-supply-using-l165 (http://www.circuitstoday.com/dual-power-supply-using-l165)
http://www.goldpt.com/virtual_ground_circuit.html (http://www.goldpt.com/virtual_ground_circuit.html)
Title: Re: Getting symetrical voltages from single suppley for opamps
Post by: MarkL on November 30, 2015, 07:13:02 pm
There is a part that does exactly what you want, also known as a "rail splitter":

  http://www.ti.com/product/tle2426 (http://www.ti.com/product/tle2426)
Title: Re: Getting symetrical voltages from single suppley for opamps
Post by: MAntunes on December 02, 2015, 08:02:00 pm
Thank you all for you help!
The rail splitter seems like a good idea. But the problem is its output current (max 20mA), but maybe combining it with a buffer could help raising the output current. Will do some tests!