Changing a VU circuit

[carbon dude oxide]

Hello i have a small VU meter project going at the moment, and i have modified this circuit so far so that it is able to vary the brightness of the LED strip acording to the loudness



However i have run into a problem currently all 3 transistors on there are: BC547B 's and the amount of LED's i want to drive from this is a little bit too high unfortunatly

I would like to replace T3 to a mosfet to be able to handel about 8-10A (12m of RGB LED strip)

How would i go about modifying this circuit so that it uses a mosfet? Or can i put several of the BC547B in parralel with ballast resistors?

[madires]

If you would PWM the LEDs then it would make sense to use a MOSFET. I'd go for a darlington configuration with a BD135 and some 2N3055.

[dannyf]

I would like to replace T3 to a mosfet to be able to handel about 8-10A (12m of RGB LED strip)

A (non-practical) solution would be to use T3's output to drive a (linear) mosfet driver / mosfet.

The only practical solution is to to use T3's output to modulate a pwm driver that drives the mosfet. One example would be to use a simplified version of your existing circuit to drive a 555 and then a mosfet, either directly or through a driver, depending on the mosfet used.