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PROTOTYPES #2,#3

A project log for Python Powered Scientific Instrumentation tool

A multi purpose lab tool accessible by simple Python functions, and capable of studying a wide range of physical phenomena.

jithinJithin 05/27/2015 at 08:210 Comments

The following changes were made

Yellow trace - DAC output to CCS circuit. Blue trace - Voltage drop across a 100 ohm load connected to CCS. The range of the constant current source is dependent on the load resistance since for higher loads, higher voltages need to provided to maintain the same current (I=V/R) , and there;s a limit to that.


testing an LM311 based tank circuit driver to use as an inductance meter.

Verifying that other function calls can be executed while the oscilloscope runs in the background. In this instance, The yellow and red traces are looking at the SPI clock and data pins, while the green is a square wave connected to a PGA. The data sent over the SPI bus is actually changing the gain of that particular PGA. One can see that once the last clock of each packet is sent to the PGA, its output(green trace) changes.

Vdd (Yellow) , AVdd (Blue) rising together since a diode was connected from Vdd to AVdd. No PIC oscillator failures have occured since.

Aluminium Capacitors can't seem to do the job for the charge pumps. They require low ESR Tantalum capacitors.

I monitored a capacitor's voltage while the CTMU was being used to estimate its capacitance using constant current charging. Q=CV => I*t = C*V [ Current, and charging time are both set by us. Voltage is measured at the end of the charging time, and therefore Capacitance can be calculated. ]

Monitoring this charging cycle using the LeCroy scope caused an increase of 13picoFarad in the measured capacitance. This value somehow tallies exactly with the 13pF capacitance specified on the LeCroy scope. No current source calibration was used.

Trying out a NanoAmmeter. The LED is used as an input source, and the output from the ammeter goes up by a few mV when I shine a light source onto the LED

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