Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Simple RC circuit - SPICE simulation

Status
Not open for further replies.
C

cmb021

Newbie level 1
Joined
Oct 5, 2015
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
15
I created the simplest circuit I could think of, a DC source in parallel with a capacitor and a resistor. When I simulate, the transient analysis yields a constant current, nothing through the capacitor. What am I doing wrong?
 

Re: Simple SPICE circuit help

I guess that the simuation time scale is much higher than RC time constant.

cmb021 said:
What am I doing wrong?
Click to expand...
You're not providing much details.
 

cmb021 said:
I created the simplest circuit I could think of, a DC source in parallel with a capacitor and a resistor.
Click to expand...

This scheme ?

rc1.jpg

When I simulate, the transient analysis yields a constant current, nothing through the capacitor. What am I doing wrong?
Click to expand...

Nothing, that's what happens after a few picoseconds.
 

There is nothing to slow down the charging of the capacitor so it charges immediately. Then the SIM program shows you a load resistor and a fully charged capacitor drawing no more charging current.
 

cmb021 - I am afraid, you have performed a TRAN analysis with a dc source.
However, you need a time-varying source which is switched on at t=0 (Vpulse).
 

The capacitor will draw no current, as it will charge immediately to the potential of the DC source. The DC source is ideal, and can provide infinite current to the capacitor, so the capacitor will draw no current (i.e. fully charged at time 0). Thus, the only current path is through the resistor. The schematic provided by _Eduardo_ is how you described your circuit.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top