Rb2 Kickbox Piezo

Discussion in 'The Projects Forum' started by Interitus, Nov 8, 2009.

  1. Interitus

    Thread Starter Member

    Nov 8, 2009
    Alright, so I made a custom rockband 2 drum kit. Seen here:

    Each pad is a Piezo, and is directly connected to the Rb2 wireless controller. Its hacked together right now because I dont want to sacrifice my wireless controller, the rb1 controller I picked up didnt work and I dont have the funds to buy a second. All the pads work directly connected except for the kick pad. The kick pedal for rockband kits simply momentarily closes the circuit, using a magnet and a magnetic switch. There were kickbox circuits on the rockband mod forum, some complicated, some easy. I tried one of the easier ones to no avail.

    What I need, is a simple circuit that will close the main circuit when the millivolts from the piezo are applied. The circuit I tried used a 2N4401 transistor, with a 10Mohm resistor to do this.
  2. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    using a 'bare' Piezo disc transducer, a light tap should give several volts but at a very high impedance.

    Try using a FET of some sort, with a gate to source resistor of about 100K in parallel with 12V zener to protect the gate from overvoltage and a bridge rectifier of 1N4148 diodes between the piezo and the source/gate of the FET so either polarity from the piezo gives + to the gate.

    You may also need a small capacitor on the gate to maintain the voltage (1nF - 10nF?), so you get a cleaner on/off for the duration of the hit, rather than every cycle of oscillation from the piezo giving a separate output pulse.
  3. bertus


    Apr 5, 2008
  4. rjenkins

    AAC Fanatic!

    Nov 6, 2005