You could just add an emitter-follower onto the opamp if you wanted.
http://forums.parallax.com/attachmen...chmentid=64757
http://hyperphysics.phy-astr.gsu.edu...c/emitfol.html
Most opamps aren't really designed as drivers. But in your application, a very simple transistor circuit is all that's needed. An emitter-follower doesn't amplify voltage, the emitter simply "follows" the base voltage. This will move the heat-generating part of the circuit to a drive transistor, and still give you that same voltage sweep from the amp. Bolt the drive transistor to a heatsink.
Does a chip like this exist? (similar to L272M)
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28th February 2012 05:13 PM #1Neon_cloud
Does a chip like this exist? (similar to L272M)
Hi
I am doing a project in which I need a Power amp (wired as a voltage follower) to power a 12v 6w bulb.
I have tried using this L272M chip, but it gets very hot, and after a while of the bulb being on, the output voltage and current of the chip both drop (The input of the chip comes from a D-A converter op amp with max output 13ish volts and an inverting op amp to keep the voltage positive)
The pin diagram I found of the chip recommends powering the L272M to +5 and -5V, but this was not suitable due to the large 13V input voltage it needs, so I tried it 0v and +15v, and it got very hot and the current and voltage output drop. Is there a chip that could pump out enough current to power this bulb and not get hot/lose output voltage/current..
Thanks
http://www.electro-tech-online.com/c...CD00000054.pdf
(The L272M chip)Last edited by Neon_cloud; 28th February 2012 at 05:15 PM.
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28th February 2012 10:16 PM #2duffy
0
Last edited by duffy; 28th February 2012 at 10:25 PM.
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