Shutter-speed tester


Posted on Feb 24, 2013

The solar cell is connected across the input of the FET (field-effect transistor), Ql, so that it will produce positive dc voltage to the gate when activated by light shining through the open shutter, decreasing the negative gate-source bias already established by the source resistor, and causes an increase in drain current. The drain voltage goes more negative which causes a decrease in Q2's base current. Q2's collector current decreases, and its collector voltage becomes more positive.


Shutter-speed tester
Click here to download the full size of the above Circuit.

There is an amplified positive-going voltage output at the collector, and it's applied directly to the oscilloscope's vertical input, producing a waveform that is displaced vertically whenever light strikes the cell.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    PWM DC Motor Speed Control
    Auto poweroff for power supplies circuit
    bluetooth controlled relay
    Bias supply powers low power Geiger Mueller tube
    TDA1562Q Audio Amplifier Circuit
    Two Simple Thermistor-Controlled Relay Circuits



    Top