I need help with L200 and boost it for more amps

[DigiSoft]

Ok, so I want to build regulated PSU with current regulation and voltage regulation. I was searching goolge for this kind of schematic and I desided to go with L200 Regulator and boost it with x5 2n3055 connected in parallel. I want to get maximum 16V and 10A regulated power suply.

So my question is this...
I know that L200 itself can controll about 2 Amps of power. So what if I boost it with x5 2n3055 NPN transistors? Can it controll those 10 Amps or am I missing somethink??

Thanks.

 

[Hero999]

Whilst is will work, it isn't a great idea as you'll need a huge heat sink you get rid of >160W of heat when it's running at 3V.

Have you built a power supply before?

I'd recommend building one with an LM317 for a current of about 1.5A before you attempt something like this.

 

[DigiSoft]

Yes I have build power supply before. I've always used power transistors for voltage regulation. But I am talking about 2A supplies. I've build 24V 10A static PSU but it is static!

I don't like LM317 because it can't controll the current or am I wrong?

Yes I know that there will be alot of heat and I will put big heatsinks and big FANs.
I think that L200 is powerfull enought to drive x5 2n3055 but i dont know if it will controll those 10 amps or so.
Can I use standard L200 voltage/current regulator schematic and add x5 2n3055 transistors, so L200 should work normal exept it would controll 10 amps. Is this possible?

 

[Hero999]

There is a circuit to control the current on the LM317's datasheet.

I would recommend a switch mode power supply for something like this, the amount you'll save in fans and heat a large sink will save you more money than the additional cost of the semiconductors, even if you power it from a mains transformer.

 

[DigiSoft]

Well I don't want switch mode power supply because it uses much more components and it is harder to build. Plus I have spare 18V 25A transformer so I want to use it for universal power supply.

I apriciate any help...

 

[Hero999]

You can use the transormer in the switch mode power supply, you don't have to build one that runs directly off the rectified mains, in fact I wouldn't recommend that. Just connect the usual bridge rectifier and filer capacitor to your transformer and stick a switching regulator on the output.

Although it will use more components, it'll still work out cheaper as big heatsinks and fans are very expensive and will outweight the cost of the extra smaller components. Building switchng power supply will also give you more experiance than just building yet another linear power supply.

 

[DigiSoft]

Ok thanks for the reply but can you help me little by showing me some schematic examples or link for this kind of supply?

Thanks again...

 

[k7elp60]

Ok thanks for the reply but can you help me little by showing me some schematic examples or link for this kind of supply?

Thanks again...

I would suggest the use of the LM723 regulator IC and a NTE251 npn darlington transistor. The 723 can be set up for current limit and will drive the NTE251 transistor, all else you would need is the rectifier the filter, heatsink and a few components.
I have designed and built many power supplys, so if you give the range of output voltages and current you want I'll help you with the design.

 

[Hero999]

The following manufacturers all sell products that will be able to do what you want. Some will even do the design work for you if you provide them with the input and output voltage/current you require.

http://www.linear.com/pc/viewCategory.jsp?navId=H0,C1,C1003,C1042,C1031
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