Activities/Turtle Art/Using Turtle Art Sensors: Difference between revisions

Tonyforster (talk | contribs)
Tonyforster (talk | contribs)
Line 11: Line 11:
Standard 3.5mm 2-pin switched mono microphone jack; selectable 2V DC bias; selectable sensor-input mode (DC or AC coupled); selectable +20dB boost.
Standard 3.5mm 2-pin switched mono microphone jack; selectable 2V DC bias; selectable sensor-input mode (DC or AC coupled); selectable +20dB boost.


If using a stereo plug it is the tip (usually the red wire) plus the earth.
On the XO-1, mono data is measured, the left channel, the tip (usually the red wire). The XO-1.5 and the XO-1.75 can read both the left and right channel.


The XO1 is protected at the input by a 5V zener diode. The allowable input is -0.5V to 5V. Inputs outside this range will cause excessive current and damage. Even a single 1.5V battery can cause damage if connected reverse polarity.
The XO-1 is protected at the input by a 5V zener diode. The allowable input is -0.5V to 5V. Inputs outside this range will cause excessive current and damage. Even a single 1.5V battery can cause damage if connected reverse polarity.


The XO1.5 is protected by a resistor,(1/16W 470 ohm SMD0402) and a pair of diodes to ground and to +3.3V which should protect -6V to +9V continuously, and up to higher voltages for shorter periods of time. Similar protection is planned for the XO1.75.
The XO-1.5 is protected by a resistor,(1/16W 470 ohm SMD0402) and a pair of diodes to ground and to +3.3V which should protect -6V to +9V continuously, and up to higher voltages for shorter periods of time. Similar protection is planned for the XO-1.75.


For the XO1, the addition of a 150k ohm series resistor would (I expect, no guarantee) give a reduced sensitivity in voltage mode (0-4V) but allow inputs to +- 100V without damage. Input impedance in resistance, volume and pitch modes is much lower but a 1k ohm series resistor should still allow inputs to +-12V.  
For the XO-1, the addition of a 150k ohm series resistor would (I expect, no guarantee) give a reduced sensitivity in voltage mode (0-4V) but allow inputs to +- 100V without damage. Input impedance in resistance, volume and pitch modes is much lower but a 1k ohm series resistor should still allow inputs to +-12V.  


<b>If applying an external voltage to the XO1, it is highly recommended that test leads be made up with a microphone plug and an inbuilt series resistor. 680 ohms is the suggested resistor value, it gives a reasonable input range while still allowing the use of the full resistance range of the XO1.</b>
<b>If applying an external voltage to the XO1, it is highly recommended that test leads be made up with a microphone plug and an inbuilt series resistor. 680 ohms is the suggested resistor value, it gives a reasonable input range while still allowing the use of the full resistance range of the XO1.</b>