Electronics 101 experiments :Diodes, BJTs , Op-Amps, FETs...

A project log for SEELablet : Instrument Cluster For Laboratories

Minimal, yet powerful combination of control and measurement tools integrated with an SBC running Python based UIs for science & Engg. Expts

JithinJithin 07/11/2016 at 16:340 Comments

Armed with a few odd basic instruments such as power supplies, voltmeters, and maybe a scope , there's quite a bit of electronic behaviour one can study.

Some simple schematics

Slightly more advanced topics

Sample Code for measuring a transistor's common emitter output characteristics

from SEEL import interface

#PVx are power supplies with various output ranges.
#set_pvx sets a voltage, and returns the actual set voltage ( corrected for least count )

pv2 = I.set_pv2( 1.0)   #  Bias the base via a 200K resistor.
base_voltage = I.get_voltage('CH3')
base_current = (pv2-base_voltage)/200e3 # Use Ohm's law to determine current
CollectorCurrent = []
CollectorVoltage = []
for a in np.linspace(0,5,100):
  pv1 = I.set_pv1(a)
  CollectorCurrent .append( (pv1 - I.get_voltage('CH1') )/1e3 )

from pylab import *
plot(CollectorVoltage,CollectorCurrent ) #Plot and try a different base current

Halfwave rectification using an LED.
The high forward threshold voltage of the LED causes the output voltage to be very low for an input waveform of 3.3V

Example results :