Circuit design for short-circuting outputs when needed

Discussion in 'Mini Quads & Racing' started by April155, Dec 13, 2016.

  1. April155

    April155 New Member

    I am working with two sensors with 4 pin as output.
    My question is simple: I want to make circuit that allows me to short circuit the output of either one of the sensors individually when needed.

    I am considering using quad 1:2 demux (AGD774a) and shorting either the pins on channel B together while measuring with channel A and vice versa.
    So when I want the channel for normal measurement I will use channel A and when I want output of sensor shorted I change the channel of the switch.

    So, my main question is whether using a demux to solve the requirement is a wise choice or there is some other way it can be achieved.

    Notes:

    • The sensor is an ultrasonic transducer which produces only millivolt level outputs.

      In use the sensor is placed in a heating chamber to increase its temperature.
      When the temperature of the transducer is varied, it produces spurious temperature-change related voltages.
      After heating we need to short the output pins to release all the residual voltage.
      The charge itself is small.

      May be I can do a worst case calculations and attach a resistance as well with it.

    • Temperature Sensors, Transducers Temperature Sensors, Transducers are in stock at Kynix Electronics. Kynix offers inventory, pricing, & datasheets for Temperature Sensors, Transducers. To know more, please view our large section of Temperature Sensors, Transducers below.
    • The voltage drop is small - in the mV range.
      I do not think that an electromechanical relay is required.

    • The sensor will not be connected to Micro-Controller.
      Shorting is needed to discharge the piezo in the sensor which occurs when the temperature is changed.
     
  2. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 @ 2ROPS Moderator

    Can't you just use two MOSFETS in series, or a Transistor to short it to ground (through a resistor if needed)?
     

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