I have an important job interview and they will be quizzing me on these questions. I have a degree in electronics but its been years since I have done this. I have a great opportunity and need a little help. Any and all help is appreciated. There are 10 questions that I could be asked. I have attached them.



View attachment 71303

 

Did someone finally turn off google?

 

Did someone finally turn off google?

I am looking for some real time help. I have googled a few things. I thought maybe I could get some better understanding than reading through pages and pages.

 

The last page is up side down.

 

Which, in particular, do you need help with?

 

The last page is up side down.

Right side up now!

 

Which, in particular, do you need help with?

I mainly need help with the schematics. I have an idea of the output for the op amp. The solenoid driver I have really no idea. I have been going through my old school books and can't find anything about it.

 

Question 8 seems a bit unclear, but, you can at least get the input voltage required for a 50% duty cycle using linear interpolation on the two points you are given.

Use: y – y1 = m(x – x1), where (x,y) and (x1,y1) are your given data points.

 

Really you lost me.

 

Really you lost me.

Read the schematic note.

When voltage at Pin 3 is 3 volts, duty cycle is 30%.
When voltage at Pin 3 is 2.6 volts, the duty cycle is 40%.
So.
A reduction of voltage at Pin 3 by 0.4 volts produced an increase in duty cycle by 10%.
You need duty cycle of 50%. To me it seems that if I reduced the voltage at Pin 3 by another 0.4 volts, I would gain another 10% in the duty cycle. So. When voltage at Pin 3 is 2.2 volts, the duty cycle will be 50%. That is why they stuck the adjustable resistor at Pin 3, so that you can decrease the the voltage drop at Pin 3 and increase the duty cycle.
And.
Based on the two points that the note provided, you can derive the linear relationship between the voltage drop at Pin 3 and the length of the duty cycle.
y=mx+b
Duty Cycle=m*Pin 3 voltage+b
30%=m*3+b
40%=m*2.6+b
Can you do this middle school math and find slope m and y intercept b?

 

Read the schematic note.

When voltage at Pin 3 is 3 volts, duty cycle is 30%.
When voltage at Pin 3 is 2.6 volts, the duty cycle is 40%.
So.
A reduction of voltage at Pin 3 by 0.4 volts produced an increase in duty cycle by 10%.
You need duty cycle of 50%. To me it seems that if I reduced the voltage at Pin 3 by another 0.4 volts, I would gain another 10% in the duty cycle. So. When voltage at Pin 3 is 2.2 volts, the duty cycle will be 50%. That is why they stuck the adjustable resistor at Pin 3, so that you can decrease the the voltage drop at Pin 3 and increase the duty cycle.
And.
Based on the two points that the note provided, you can derive the linear relationship between the voltage drop at Pin 3 and the length of the duty cycle.
y=mx+b
Duty Cycle=m*Pin 3 voltage+b
30%=m*3+b
40%=m*2.6+b
Can you do this middle school math and find slope m and y intercept b?

Yes thank you. I guess I need glasses.