Components: 1x Diode, 1x LED
I used my multimeter on the diode test function to identify the anode and cathode of the diode and LED:
The Led gave a reading of OL in forward biased and returned a reading of OL in reversed biased. The OL reading tells me that it is the LED has to have current running through it to pick up a reading.
The diode gave a reading of 521mv in the forward biased direction which i know is the anode already, however the giveaway was when I tested the diode in reversed biased and obtained a reading of OL (overload). This is because voltage only flows through a diode one way resulting in OL when reversed biased voltage is measured.
The anode and cathode of a diode can be identified without an ohmeter by the marking on the diode at the cathode (negative) end.
Experiment No. 2 Cont.
Components: 1x Resistor, 1x Diode, 1x LED
Vs=5v, R=1KΩ, D= 1N4007
I have been asked to calculate the current flowing through the diode and then to check it by measuring with an ammeter.
- Calculated current = I=V/R
= I= 0.005A
= I=3.2mA
- Measured Current = 6.2mA
Now I am to calculate the Potential Difference across the diode. I know from general specifications that the PD of a diode is 0.6-0.7v and when I measured to check my answer with my voltmeter I obtained a reading of 0.63v which was expected.
The maximum current that can flow through the diode 1N4007 is 1A.
For the 1KΩ resistor used the maximum value of Vs which can flow through the diode and still have it operating safely is 1000v.
In the previous circuit I will now replace the diode with a Light-Emitting Diode (LED) and calculate the current, followed by measuring it with my ammeter.
- Calculated current = I=V/R
= I=0.005A
= I=5mA
- Measured current = Too small of a current to pick up on my ammeter, as shown by the low calculated result that I obtained.
