[Question] Monitor Super Capacitor Voltage

Hello All,

I am trying to implement a design for a Super Capacitor charger that will monitor the voltage on the super capacitors while they are charging using an Analog to Digital converter from an 8051 micro controller. The attached image shows what I am basically trying to do. I want to replace ?1 and ?2 with whatever will work, can be resistors, capacitors, transistors, op amps, etc.

Thanks for any help!!!

Edit:
Forgot to add, the input to the ADC must be proportional to the voltage across the capacitors. The voltage powering the uC can be static.
Thanks.

This seems to be an exam problem so really you should find the answers yourself.
However it is a bit odd so you will struggle.
I'm not sure if any 8051 runs at 3.3 volts, but I am sure no 8051 has a built in ADC.
There may members of the 8051 family with an ADC, but that is not what the question says.

I have no idea what ?2 is for !.
If the micro (whatever it is) is to control the charger it must have a connection to the charger.
None is shown in the diagram.

I can help with ?1.
Do a search for 8051 circuits.
See how the 8051 gets its 5 volt supply.

This is actually not for a test but for a project. The 8051 is optional and is only needed to measure the voltage and then turn on LED's as the voltage rises. For my design I am using an 8051F340 which has 1 ADC built in. It also runs on 3.1 volts. I know this for a fact as I am currently using the 8051 as programmed using assembly language and running it off of 3.1 volts. That being said, I am not trying to control the charge level of the capacitor using the 8051 I just want to monitor it.

At first I was thinking that the cap charger will output 14.5 amps but then I remember that it would be 14.5 amps if the circuit was S.C.'d. Now I am thinking about attaching an Op Amp to reduce the voltage read from the cap's to around 2.4v, using a 1kohm resistor to reduce the current should there be excess current going in that direction.

Think this would work?

This is actually not for a test but for a project. The 8051 is optional and is only needed to measure the voltage and then turn on LED's as the voltage rises. For my design I am using an 8051F340 which has 1 ADC built in. It also runs on 3.1 volts.
...
That being said, I am not trying to control the charge level of the capacitor using the 8051 I just want to monitor it.

Bweiss

Well that makes more sense.
An 8051F340 is a much better device than an 8051 and seems wasted on turning
indicators LEDs on or off.

Where is the diagram from ?

At first I was thinking that the cap charger will output 14.5 amps but then I remember that it would be 14.5 amps if the circuit was S.C.'d. Now I am thinking about attaching an Op Amp to reduce the voltage read from the cap's to around 2.4v, using a 1kohm resistor to reduce the current should there be excess current going in that direction.
Think this would work?

Bweiss

I'm not sure what you are asking.
Do you have a capacitor charger or do you need to build a charger circuit?

Use a simple voltage divider using two resistors to bring the capacitor voltage down to
suit the ADC input.