Power Supply design

[col_implant]

Hi,

I'm designing a power supply and there seems to be a infinite number of power management components out there. I'm wondering if someone might be able to help narrow my search.

Im using a standard plug 9V DC input. I need to generate analogue supplies of +/-15V, +/-5V, +/-2.5V a digital supply of +5V My current requirement on these supplies is an average of 50mA sourcing and sinking which will never peak above 100mA)

I need another supply which is adjustible from +/-2.5V to +/-5V and which can provide higher current (maybe 100mA average but 200mA peak)

Does anybody know a single device which can provide a range of supplies? I would have thought this is a pretty standard problem. I'm wondering if I would be wasting a whole load of time by doing my own boost conversion, inversion, regulation of each supply on its own..... Surely there is some device/design out there I could use?

Any help or advice is greatly appreciated

C

 

[MikeMl]

Peruse all of the surplus electronics dealers like Maplin, MJPA, Allelectronics, EBay, etc. They will frequently have something ready made which comes close... I have lacked lots of pre-made supplies to make them variable, or tailor their output to what I need...

 

[RadioRon]

Hi,

I'm designing a power supply and there seems to be a infinite number of power management components out there. I'm wondering if someone might be able to help narrow my search.

Im using a standard plug 9V DC input. I need to generate analogue supplies of +/-15V, +/-5V, +/-2.5V a digital supply of +5V My current requirement on these supplies is an average of 50mA sourcing and sinking which will never peak above 100mA)

I need another supply which is adjustible from +/-2.5V to +/-5V and which can provide higher current (maybe 100mA average but 200mA peak)

Does anybody know a single device which can provide a range of supplies? I would have thought this is a pretty standard problem. I'm wondering if I would be wasting a whole load of time by doing my own boost conversion, inversion, regulation of each supply on its own..... Surely there is some device/design out there I could use?

Any help or advice is greatly appreciated

C

Yes, you seem to have chosen a very complex and awkward path using switching regulators and converters and I think it could be an awful lot simpler. Your current requirements are quite modest for a power supply, so it makes sense to me to start with a transformer that is suited to delivering the highest voltage, that is +/- 15 V (using a center tapped transformer or one with two secondarys) then use simpler linear regulators to drop down to +/- 5V and +/-2.5V. Better still, if I were you I would design a supply with several positive and negative outputs and make them all adjustable over a range of 1 to 15Volts. If it is for bench use, this would be the most flexible arrangement, and is easily done with the right design.

Is this a one-off for your own use, or a production item? Is it for supplying a specific load, or general use as a supply for experiments and projects?

 

[tcmtech]

Most likely you will need to make multiple converters to handle each +- voltage level if you going for any degree of efficiency or if each voltage range needs a reasonable level of regulation.

There are many basic and small switching type driver IC's that can be configured to provide equal +- voltages at the outputs. But still to get all the different voltages you require you may need to have an individual one for each range. Or to have one that is the critical regulated range and the others are secondary and can have slightly higher or lower variations in their voltages as the primary range is loaded and unloaded.

 

[MrDEB]

mighjt give you some direction?

**broken link removed**

 

[col_implant]

Your current requirements are quite modest for a power supply, so it makes sense to me to start with a transformer that is suited to delivering the highest voltage, that is +/- 15 V (using a center tapped transformer or one with two secondarys) then use simpler linear regulators to drop down to +/- 5V and +/-2.5V.

This sounds like a nice solution. But isnt the transformer an inherently AC device? Do you propose that I step down AC mains (230V) and rectify to get the +/- 15V?

Is this a one-off for your own use, or a production item? Is it for supplying a specific load, or general use as a supply for experiments and projects?

This is for my own use right now, it is for a research project and commercialisation is down the line, so for now I'm looking for the simplest solution. I'm designing for a specific load, but this load may evolve.

Thanks for the help

C