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Bd 241c VU meter from a 100 mA ammeter? Answered

I want to make a VU meter from my 100 mA ammeter with my bd 241 c transistor. Is it possible in an easy way, or I 'm just spending my free time with my doing nothing? :D Please take into consideration that I'm a really beginner, so explain like this.


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8 years ago

Normally you can convert a 50 uA meter to any kind of other meter.

To make a VU meter ( 0-15VDC @ FS full scale ) from a 0-100mA FS.
  • Measure the resistance with your multimeter = Rm ohms.
  • We assume your audio amp can deliver 100ma at 15v
  • Rt = 15/o.1 = 150 ohms
  • IF Rt = > Rm we can simply add a resistor Ra
  • Such that  Ra = Rt - Rm  easy-peasy  = 150 - Rm
  • But  IF Rm is greater then 150 you will have to use a power Op-Amp.
  • It is better to buy a VU kit then too try making the 100ma work !


8 years ago

Probably not.

What kind of Ammeter is it and what components does it use?

have you tried looking up schematics for various DIY VU meters to see what you may need to complete this project?