Modifying DVD power supply for my other scope?

[Satamax]

Hi everybody!

Well, i have that broken DVD player with a power supply a bit like a computer supply, +12V -12V and +5V plus ground. Any idea on how i could make that +9V to be able to power my Tekmetter (metter+scope) instead of using LR06 batteries (6 of them and it's eating through them!)

Thanks.

Bye.

Max.

[Satamax]

Could i just do a voltage divider on the 12V rail????

[theelectic]

Try a simple 9V regulator. What's the current requirement of your scope? And how much can that power supply put out?

[Satamax]

I should know! But i don't! Basicaly the tekmetter takes 6 LR6 batteries. What you mean by try a simple 9v regulator? You mean i should make one? Or replace the regulator in the power supply from the DVD player to get 9 volts? Isn't an IRF or similar regulator tunable???

Bye.

Max.

[Enzo]

I doubt it even has to be regulated, after all the thing still works as the batteries fade.

By 9 volt regulator he means a three terminal regulator - a 7809. SImple as can be.

Before you go all the way though, look carefully at the scope. Is there a tap after three batteries? Part of the circuit might want split supply.

[Satamax]

Hi Enzo!

There's only two "tabs" connectors exiting the battery case to conect into the scope. Ok so a simple wall transformer with rectified 9V output should do the trick.

Thanks a lot

Max.