CONVERT from 15-0-15v to 9v

[polyal]

i have a mains powered 1khz test tone oscillator i need to
make portable
i need to convert it from 15-0-15 split rail to 9v ( battery )
this circuit generated 10v p/p
what modifications do i need to do to get about a 2v p/p sine wave
cheers reg

 

[danadak]

Single supply sine generators :

https://www.ti.com/lit/an/slyt164/slyt164.pdf?ts=1665140158285&ref_url=https%253A%252F%252Fduckduckgo.com%252F

Single supply considerations :

https://www.ti.com/lit/an/sloa030a/sloa030a.pdf

https://www.ti.com/lit/an/sboa059/sboa059.pdf?ts=1665104143826&ref_url=https%253A%252F%252Fwww.google.com%252Fsearch%253Fq%253Dhow%2Bto%2Bpower%2Ban%2Bopamp%2Bwith%2Bsigle%2Bchannel%2Bpower%2Bsupply%2526ie%253Dutf-8%2526oe%253Dutf-8%2526client%253Dfirefox-b-1-m

Regards, Dana.

 

[Alec_t]

This should do what you want :-

Note the new split supply with a virtual ground (4.5V), the addition of a 10k pot to give you an adjustable output amplitude, and that the non-inverting inputs of the op-amps connect to the virtual ground. The other component values are unchanged.

 

[polyal]

thanks . . i will try that
regards
reg

ps is the pot grounded at the battery negative or should it be at
the virtual earth ? ie is the signal relative to the batt negative

 

[Alec_t]

The pot can be grounded at either, since the output is capacitor-coupled. What will the pot output be feeding?

 

[polyal]

it works spot onwith either ground or -ve
i'm getting a 1v p/p sine wave ♪♪ ( at the op amp o/p )
is there anyway i can squeeze another 1volt gain out of it
it will be used for signal tracing through audio gear typically
at line level ( mixers etc )
the circuit is from a vintage soundcraft delta mixer
thanks
reg

 

[Alec_t]

i'm getting a 1v p/p sine wave ♪♪ ( at the op amp o/p )

Which op-amp? (Either should give at least 5V peak-to-peak output if all component values are as shown in the circuit I posted.)
Do you have both non-inverting inputs (pins 3 and 5) connected to the virtual earth?
Are you sure the battery is putting out 9V under load (~9mA or more)?
What load do you have on the pot wiper?
What is the virtual earth voltage relative to battery negative?

 

[polyal]

thanks for the reply
it turned out to be a build fault due to using recycled
strip board with cut track ( R10 was not connected to virtual earth )
it has now been rectified and giving a healthy 4v p/p sine wave
thanks for your help . . well chuffed
♪reg♪