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:

New Circuits

.

 


Popular Circuits

9-Bit-cmos-converter
80M-amateur-radio-transmitter
Analog Delay Line (Echo And Reverb)
USB powered device with multiple Decoupling Capacitors
Connection Tester
PIC Stepper Motor Tester
Car Alarm Simulator
Monostable circuit diagram of the use of video amplifiers and comparators



Top