Tuesday, March 9, 2021

Adding the .startup command will cause the circuit to start with 0 volts.


I set the scan for 2 seconds so the circuit could stabilize.

So this is what happens while the capacitors are charging.

The battery resistance is at 0 ohm. When we add the battery resistance what effect will that have?

I saw a recent post that said the bigger the caps the better. This series of post will explore that idea. 

So the idea is to look at what we have and vary the circuit to get a better response.

I put this circuit on a board and it was quite sensitive and quite unstable.

We need to consider the battery resistance. A fresh 9 volt battery may have 2 Ohms internal resistance. As it ages that may go much higher. How to look at the battery resistance will be coming shortly.


  1. Hello Mr Reset. What was your reasons for powering the circuit on the left hand side of R7.

    Thanks, Amie.

  2. It is just how I draw circuits. If it was a high frequency circuit I would Set the power points so the currents would be unidirectional.