This was done in a lab setting where we increased the supplied voltage in increments of 0.25 v and measured the voltage drop across the diode each increase.Welcome to AAC!
There could be multiple reasons. We need more context.
Since this is homework, why do you think it was done?
I was not given that information.What is the maximum current through the diode?
Based on the lack of relevant information, I see no reason to use two parallel resistors.I was not given that information.
As has already been stated, we need more context/information. Could be any of a number of reasons, none of which are obvious. Maybe the lab instructor just has a thing for 470 ohm resistors?The question I need help with is simply, "Why are two 470 ohm resistors used in parallel when a standard value 240 ohm resistor is available and could easily be obtained? (Ignoring the 5 ohm difference)"
What was your supply voltage, at its maximum? At that voltage (minus whatever the diode drop was), what would be the power dissipation of a 240 ohm resistor? What is the maximum power the resistor is rated for? With a pair of 470 ohm resistors in parallel, how much power is each resistor dissipating at that voltage?This was done in a lab setting where we increased the supplied voltage in increments of 0.25 v and measured the voltage drop across the diode each increase.
Hi,View attachment 200156
Here's my crudely drawn circuit. The question I need help with is simply, "Why are two 470 ohm resistors used in parallel when a standard value 240 ohm resistor is available and could easily be obtained? (Ignoring the 5 ohm difference)"
Thanks in advance.
From post #3.Is this a real life experiment or are you supposed to do this in spice?
This was done in a lab setting where we increased the supplied voltage in increments of 0.25 v and measured the voltage drop across the diode each increase.
I don't think he is using two power supplies. He stated that the drawing was crude. Note that, as drawn, the total output across the supplies is always zero. I'm guessing that he is using one output of a multi-output bench supply or perhaps using a dual output supply and either only adjusting one of them or that it is a tracking supply. The details would depend on their lab bench setup.But if you are going to ask this question, then why not ask why there are two voltage sources as well. Do you understand why they are using two voltage sources one positive and one negative?
What was the highest voltage you applied to your circuit?This was done in a lab setting where we increased the supplied voltage in increments of 0.25 v and measured the voltage drop across the diode each increase.
The reason I am asking this question is that I really don't know the answer. I can try and guess that it has something to do with the voltage being dropped over two simultaneous resistors before reaching the diode but beyond that, I am lost. I really don't understand why you wouldn't just be able to replace it with a 240 ohm resistor in series...
Thanks for your response.
by Aaron Carman
by Aaron Carman
by Aaron Carman
by Aaron Carman