Voltage division doesn't 'accept' piezo speaker

Discussion in 'General Electronics Chat' started by Emil Skovgaard, Nov 9, 2015.

  1. Emil Skovgaard

    Thread Starter Member

    Jun 6, 2015
    As i had good experience receiving help last time i asked a question i will try again,

    I have attached the circuit down below.

    I'm supplying the circuit with 3.0V. I'm using a voltage divider because i want a precise value for my piezo speaker. I want my piezo speaker to receive 0.88V (is going to be fitted in a bigger circuit). My R1 is set to 100 Ohms, and my R2 to 42 Ohms. By doing this, i can measure 0.88V at the pin going to the speaker (when the speaker is NOT there). But when i insert my piezo speaker, and measure the voltage, it drops to around 0.546V.

    How can this be? Has it something to do with the piezo speaker having a inner resistance or something like that?
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009