47Kohm Resistor reduces 5Volt battery by how much ?

Hi,
Im new to electronics and I have a lot of questions swimming around here's just a few.

Q. If a resistor has a value of 47Kohm then how much does it stop the battery down by and how do you figure this out. (Ohms Law maybe?)

Q. If I have a 9Volt battery going into a LM555 IC will the IC blow?
How do I findout the capacity of the IC ? Can I use a multimetter to test it ? and once I know that, how do I figure out what size resistor I need to go between the 9V battery and the IC ?

Thanks in advance..

Justin.

mettam said:

Q. If a resistor has a value of 47Kohm then how much does it stop the battery down by and how do you figure this out.

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The battery has an internal resistance that gets higher as the battery runs down. Then you simply have two resistors in series making a voltage divider. 47k draws such a low current that you won't notice the voltage drop with it connected to a new 9V battery.

Q. If I have a 9Volt battery going into a LM555 IC will the IC blow?

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Look at the datasheets for ICs. They show the max limits, spec's and which pin does what. I go to www.datasheetarchive.com and the absolute max supply voltage for an LM555 is 18V but a max of 15V is recommended.

how do I figure out what size resistor I need to go between the 9V battery and the IC ?

Click to expand...

A resistor is not required.

I can't really add anymore than AudioGuru has, but you may find these links interesting:

https://www.electro-tech-online.com/threads/ohms-law.430/

https://www.electro-tech-online.com/threads/voltage.32/

Brian

Before you even think about using a 555 you should make sure you understand ohms law properly, the fact you've asked such uninformed questions proves you don't.

https://www.the12volt.com/ohm/ohmslaw.asp
https://www.electronics-tutorials.com/basics/ohms-law.htm
**broken link removed**
https://www.hobbyprojects.com/dc_theory/ohms_law.html

audioguru said:

A resistor is not required.

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Not only it is not required, I guess it is a very bad Idea to put one for an IC. How do you know the current the IC is drawing at a given time? It can't be predicted. If the IC starts drawing more current (say when the PIN 3 goes high) the voltage drop across the IC would change and hence the reference voltage and disturb the timing cycle.