Voice Modulator

Discussion in 'The Projects Forum' started by oodes, Oct 3, 2012.

  1. oodes

    Thread Starter New Member

    Apr 3, 2012
    12
    0
    Hey Guys ,

    Im looking to build this Voice Modulator as a Hobby project
    http://www.circuitstoday.com/voice-modulator-circuit

    However im finding it impossible to find the HT82V733
    240mA Audio Power Amp which is IC2(Can find it in SMD but i need through hole) . Any recommendations on what I can use instead and is readily available. I know this will be no problem for you whizzes out there :D

    Thanks in Advance

    Des
     
  2. vk6zgo

    Active Member

    Jul 21, 2012
    677
    85
    There are a lot of audio amplifier ICs that you could use in the IC2 position,but they may well have different pinouts,which may be a problem if you have a ready made PCB.
    Also some may not work on a 4.5volt supply.

    If you can get the SMD device,how about piggybacking it on a piece of
    Vero/vector board, & fit pins that will suit the DIL socket?
     
  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    A TDA2822 audio power amplifier works with a supply down to only 1.8V. It is in an 8-pins DIP package.
    But with a 4V supply (a battery?) the amount of power from any amplifier is extremely low.

    Who will hear it? Halloween kids at the door?

    If you make it loud enough to be heard then it will probably produce acoustical feedback howling since the microphone will also hear its own output.
     
  4. oodes

    Thread Starter New Member

    Apr 3, 2012
    12
    0
    Cheers Guys ,

    I managed to order some free samples from Texas Instruments of the LM386 and this will run of 4V. I also managed to locate a TDA2822 in my kit and I was unsure if I could use this but I can give it a go now.
    The piggybacking idea is great , I always wondered if this was possible so thanks also for this , I wont hesitate to try this in future projects.
    Cool the acoustic effect should be interesting.
    Thanks Lads , ill let u know I get on

    Regards

    Des
     
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Where will the 4V come from? No battery is 4V. Maybe a dead 4.5V battery?

    With a 4V supply, the output power at clipping of an LM386 amplifier into an 8 ohm speaker is only 0.075W which is almost nothing.

    A TDA2822 has 16 pins. When bridged with a 4V supply its output power at clipping into an 8 ohm speaker is 0.6W like a clock radio. A TDA2822M has 8 pins.
     
  6. oodes

    Thread Starter New Member

    Apr 3, 2012
    12
    0
    Was just gonna run it of a power supply to see if I could get it working first, yep the chip I have is a TDA2822M, this will work ok?
     
  7. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The TDA2822M will work fine when you connect it as the bridged amplifier shown on its datasheet.
     
    oodes likes this.
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