build a power supply! please help!!!

[auto_mitch]

hi!
could u help me to built a power supply at 33Vdc / 16A????
i thought to use a LM317T for the voltage but the output is only 1.5Amp how can i increase it at 16Amp??
one good solution is to use transistors as amplifiers but i dont know how many!!!
thanks anyway

 

[udi_hakim]

For what do you need such high ratings?
you may want to drop the regulation and use just a transformer and a big table diode bridge it could give you a nice DC signal.

if the regulation is so important You can parallel the regulators for higher currents, but the 317 is not a good choise as you will need at least 12 in parallel...

You can also search for a DC/DC converters that will give you such high ratings.

 

[bmcculla]

At that current you wil probably want to use a switching regulator. 16A is a lot of continuous current.

Parelleling regulators is a bad idea as one invariably will be supplying more current than the others and blow up causing the others to blow up too.

You might be able to build your own regulator with an op amp and a couple pass transistors (you can parallel tranistors because they have a positive temperature coefficient. So as they heat up the supply less current) You'll need a very large heat sink though.

Brent

 

[udi_hakim]

Parelleling regulators is a bad idea as one invariably will be supplying more current than the others and blow up causing the others to blow up too.

Why is that?
I parlleled regulators several times and never had any problems...

Also you can look at the regulators datasheets and a lot of manufactors recommends paralleling for high currents.

 

[Roff]

At that current you wil probably want to use a switching regulator. 16A is a lot of continuous current.

Parelleling regulators is a bad idea as one invariably will be supplying more current than the others and blow up causing the others to blow up too.

You might be able to build your own regulator with an op amp and a couple pass transistors (you can parallel tranistors because they have a positive temperature coefficient. So as they heat up the supply less current) You'll need a very large heat sink though.

Brent

MOSFETs have positive tempco's, and you can safely parallel them as regulator pass elements. Bipolar transistors have negative Vbe tempco's, and current hogging / thermal runaway may occur if you put them in parallel unless you add small emitter resistors to balance the current sharing.

 

[Roff]

Parelleling regulators is a bad idea as one invariably will be supplying more current than the others and blow up causing the others to blow up too.

Why is that?
I parlleled regulators several times and never had any problems...

Also you can look at the regulators datasheets and a lot of manufactors recommends paralleling for high currents.

Can you supply URLs of these datasheets?

 

[gerty]

Do you have a transformer picked out yet??If not the small industrial electric pallet trucks and golf carts use a 36v 30 amp battery charger..Variacs (variable transformers) are getting cheaper all time also.

 

[ukeee]

Most regulator datahseets suggest using a pass transistor to increase the current rating of the power supply. It's usually quite simple to add one and many manufacturers will suggest circuits for doing so.

 

[TKS]

mhhh cant

you just 2 more for shure..??

than you cant stress no one...

Parelleling regulators is a bad idea as one invariably will be supplying more current than the others and blow up causing the others to blow up too.

greetz,


TKS