help with op amp

[mybad]

hi

i'm prety new here and their is somting i would like to ask

i need op amp that can provide me outpot of minimum 30v , 15A (or 30-50v and 20-25A or higer )
i serched the net but it was difficult to me to find one of those op amp

im sorry if i have a lot of mistekes with my english

10x

 

[geraldfryjr]

Basically what you need is 1000watt power amp that can drive 1 ohm loads !!!!!

jer

 

[cowboybob]

Welcome, mybad!

Don't know of an opamp with those power level tolerances (doesn't mean they don't exist).

Much easier (and no doubt cheaper) to use any old opamp (741 for example) to then drive some manner of power amp (as geraldfryjr suggests).

What sort of signal do you wish to amplify? AC (what frequencies), DC, something else?

What is your load?

 

[MikeMl]

30V @ 15A means that the load resistance is E/I = 2Ω

30V at 15A means that the peak power into the load is E*I = 30*15 = 450W, so you will need a 30V 450W power supply.

If you do this with a linear power amp, it will produce a maximum power dissipation when its output is at the mid point where the load current is E/R = (30-15)/2 = 7.5A. The maximum dissipation in the power amp is 15*7.5 = 112.5W.

Linear power amps do exist, or can be built with a few components; however at this power level they require a HUGE heatsink (more than a square meter of aluminum).

The component you seek is a "servo amplifier". A modern one uses Switch-Mode to eliminate most of the power dissipation in the amplifier. However, I predict you will be back asking how to build a linear amp after you determine how much a servo amp costs...

 

[simonbramble]

Do you actually need to amplify a signal or just generate a stable DC voltage? Very rarely would you need to have an op amp with such high output power. It can be done, but not in one component. Tell us what you are trying to do and we will try to figure out a way of doing it.

 

[unclejed613]

there is a company that does make high power op amps, but at several hundred dollars each, plus the cost of the power supply components you will need, it's better to build your own. most standard class AB audio amplifiers are just a big op amp. if you're looking for a DC output, however, an amplifier is overkill. a regulated power supply is a less expensive way to do it. are you looking for DC out, or AC?

 

[ronsimpson]

Tell us what you are trying to build. That will help us help you.