Notes:
This circuit is the result of Andy Collinson research. He
has used a photodiode, SFH2030 as an infra red sensor. A MOSFET
opamp, CA3140 is used in the differential mode to amplify
the pulses of current from the photodiode. LED1 is an
ordinary coloured led which will light when IR radiation is
being received. The output of the opamp, pin 6 may be
connected to a multimeter set to read DC volts. Infra red
remote control strengths can be compared by the meter
reading, the higher the reading, the stronger the infra red
light. He aimed different remote control at the sensor from
about 1 meter away when comparing results. For every microamp of current through the photodiode, about 1 volt is
produced at the output. A 741 or LF351 will not work in this
circuit. Although he has used a 12 volt power supply, a 9
volt battery will also work here. |
