power supply

Thanks for the replies, much appreciated. I havn't been doing electronics for a long time, only two years. The current at the input is continuous current, 12V'CC'. It wasnt specified to me what the currents should be at the output voltages. Thanks for the information.

Thanks Chris, that website is very helpful. Cheers. Thanks for the other replies too. Appreciate your time.

As described, the question is basically 'unanswerable'. You need to know the stability/accuracy required on the outputs, whether isolation is required, what currents are involved, and what the input voltage range really is (for example, if the incoming 12v, is already stable, and accurate, it can directly provide the output 12v - if it can only ever go 'below' 12v, and isolation is not required, you can use a 'boost' inverter - if the -12v, only requires a 'nominal' voltage, and current is low, a switched capacitor inverter may meet the requirements, etc. etc.).

Best Wishes

___ | | Astech AA05E-012L-050S + 12V ---+----| |------------------------------- +5V | | | | |___| | | | GND | | ___ | | | Astech AA05E-012L-120D `----| |------------------------------- +12V | | | |------------------------------- -12V |___| | GND

Please See:

You may paypal me my design fee. ;-P

Cheers! Rich

Ken, don't you think we can be a little more helpful than that?

5V OUT .----------------- | 5V --- - | o-----------o---------------- | | | === --- === GND 12V - GND | | | | -12V OUT '---------------- (created by AACircuit v1.28.5 beta 02/06/05

Here, if you don't need much current then this should run solidly for a few years. Finding the 5V battery is left as an exercise for the student.

Now might I ask why it is that you're required to build something that needs to meet no useful specifications?

I read in sci.electronics.design that snipped-for-privacy@gmail.com wrote (in ) about 'power supply', on Thu, 28 Apr 2005:

This is hardly a job for someone who hasn't been doing electronics for a long time. What currents do you need at each voltage? And the schematic is only about 20% of the project.

Have a look at

scroll down to the bottom for your circuit.

Cheers.

I read in sci.electronics.design that snipped-for-privacy@gmail.com wrote (in ) about 'power supply', on Thu, 28 Apr 2005:

Then tell whoever is 'requiring' you to do an impossible task that he may be god but you aren't.

Here: --------------- ! !

Just cut an paste this in.