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+ 15 /-15 and +5 volt power supply


diablojoy

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Jaycar in oz sell a regulated power supply providing +15/-15 /+5 in kit form

from Aud $17.95 each for board and components cat. no.kc5418

and a suitable toroidal transformer cat. no. MT2086 from Aud $21.95 with a better price on multiples

as far as i can tell they will ship outside australia if ordering online

and considering the state of the aussie dollar at the moment

it could be worth checking out.

http://www.jaycar.com.au

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I don't think you would need to do even that the regs used for the +15 / -15 are adjustable

you only need to change 2 resistors on each side i haven't checked it out fully yet but i think i may

be able to add a couple of trimmers to adjust the outputs  so exact voltages can be obtained

they specify at the moment the standard cct to be within +-5%  I want to see if i can improve on that

I will look into the data sheets of the regs and see what i can come up with they are

LM317 and LM337.  any input would be very much appreciated  :)

4140_power_supply_jpg6a8b257895538f11235

4140_power_supply_jpg6a8b257895538f11235

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yes modify with 2k trimpots in place of the 1.1k resistors

then adjust to your requirements roughly 3 volts up to about 25 volts usefully

I guess. current supply will drop off at higher volts and heat becomes an issue

at lower volts however between 10 and 18 volts should be good for about 1 amp

you do need to recheck and adjust once you have connected up whatever you are powering

as the voltage will drop roughly by 1 volt once a load is connected .

cheers  :)

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  • 1 month later...
  • 2 months later...

I have built +15/-15 from +12 using two MC34063A. Inductors are a little bit noisy and I can hear sound, when they have load, but this DC-DC changer works perfectly. Online calculator that also draws schematic can be found here: http://www.nomad.ee/micros/mc34063a/index.shtml

Used these values:

Vin:12V

Vout:-15V

Iout:200mA

Vripple:5mV

Fmin:30kHz

Sorry for mistakes :)

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Inductors are quiet noisy

Quiet Noisy?? Sounds a  bit confusing. :-)

Switchers are great for efficiency, but they can create electrical noise that might be heard in an audio signal.

Since most of the bipolar supplies needed around here are for audio, I prefer to use linear regulators.

But that's just my opinion. I'm really glad it works for you.

One thing I really like about 7815/7915 or 7812/7912 is that they are not adjustable, so there's a few less things that need to be adjusted. I just like to keep it simple when I can.

Have Fun,

LyleHaze

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