Problem with input waveform (voltage) while using PSpice

[[email protected]]

I am constructing and simulating a full-wave rectifier circuit using
the PSpice software. The circuit consists of an ac source, 4 BJTs in a
bridge design, and a resistor and capacitor connected in parallel
after the bridge. An input probe is placed near the ac source, and an
output probe is placed at the junction between the resistor and the
capacitor. The output waveform shows a desired dc voltage. However,
the input waveform fluctuates between +9.2011V and -835.622mV, and not
the required +/-10V. How can I get an input waveform of +/-10V? When I
connect the ac source to a separate (and simpler) circuit, the input
waveform shows +/-10V. Why is it that the input waveform can change
with different circuits?

 

[qrk]

I am constructing and simulating a full-wave rectifier circuit using
the PSpice software. The circuit consists of an ac source, 4 BJTs in a
bridge design, and a resistor and capacitor connected in parallel
after the bridge. An input probe is placed near the ac source, and an
output probe is placed at the junction between the resistor and the
capacitor. The output waveform shows a desired dc voltage. However,
the input waveform fluctuates between +9.2011V and -835.622mV, and not
the required +/-10V. How can I get an input waveform of +/-10V? When I
connect the ac source to a separate (and simpler) circuit, the input
waveform shows +/-10V. Why is it that the input waveform can change
with different circuits?

Post your Spice netlist (I think thats the .out file) if it's not too
long. Sounds like you have your source configured wrong or connected
wrong.

 

[Marra]

If I couldnt work out if a simple bridge worked without using spice I
would seriously give up electronics.

If spice cant even get that right then god help us !

 

[Jim Thompson]

If I couldnt work out if a simple bridge worked without using spice I
would seriously give up electronics.

If spice cant even get that right then god help us !

Thus speaks the village idiot ;-)

...Jim Thompson

 

[Helmut Sennewald]

I am constructing and simulating a full-wave rectifier circuit using
the PSpice software. The circuit consists of an ac source, 4 BJTs in a
bridge design, and a resistor and capacitor connected in parallel
after the bridge. An input probe is placed near the ac source, and an
output probe is placed at the junction between the resistor and the
capacitor. The output waveform shows a desired dc voltage. However,
the input waveform fluctuates between +9.2011V and -835.622mV, and not
the required +/-10V. How can I get an input waveform of +/-10V? When I
connect the ac source to a separate (and simpler) circuit, the input
waveform shows +/-10V. Why is it that the input waveform can change
with different circuits?

Hello,

Your observed waveform (+9.2V,-0.8V) referenced
to GND is correct.

If you probe directly across the voltage source,
you will see the +/-10V.

Best regards,
Helmut


Netlist version for every SPICE, test.cir


* Rectifier
D2 vb out 1N914
D3 0 va 1N914
D4 0 vb 1N914
V1 va vb SINE(0 10 50)
R1 out 0 100
C1 out 0 1m
..lib C:\Programme\LTC\SwCADIII\lib\cmp\standard.dio
..tran 100m
..end


Schematic version for LTspice, test.asc

Version 4
SHEET 1 880 680
WIRE 64 96 -96 96
WIRE 144 96 64 96
WIRE 192 96 144 96
WIRE 384 96 256 96
WIRE -96 160 -96 96
WIRE 208 208 96 208
WIRE 384 208 384 96
WIRE 384 208 272 208
WIRE 448 208 384 208
WIRE 496 208 448 208
WIRE 384 224 384 208
WIRE 496 224 496 208
WIRE -96 320 -96 240
WIRE 64 320 -96 320
WIRE 96 320 96 208
WIRE 96 320 64 320
WIRE 144 352 144 96
WIRE 208 352 144 352
WIRE 304 352 272 352
WIRE 384 352 384 304
WIRE 384 352 304 352
WIRE 496 352 496 288
WIRE 496 352 384 352
WIRE 496 384 496 352
WIRE 96 448 96 320
WIRE 208 448 96 448
WIRE 304 448 304 352
WIRE 304 448 272 448
FLAG 496 384 0
FLAG 448 208 out
FLAG 64 96 va
FLAG 64 320 vb
SYMBOL diode 192 112 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode 208 224 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D2
SYMATTR Value 1N914
SYMBOL diode 272 336 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D3
SYMATTR Value 1N914
SYMBOL diode 272 432 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D4
SYMATTR Value 1N914
SYMBOL voltage -96 144 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 10 50)
SYMBOL res 368 208 R0
SYMATTR InstName R1
SYMATTR Value 100
SYMBOL cap 480 224 R0
SYMATTR InstName C1
SYMATTR Value 1m
TEXT -104 8 Left 0 !.tran 100m
TEXT -104 32 Left 0 !.options plotwinsize=0

 

[Jamie]

I am constructing and simulating a full-wave rectifier circuit using
the PSpice software. The circuit consists of an ac source, 4 BJTs in a
bridge design, and a resistor and capacitor connected in parallel
after the bridge. An input probe is placed near the ac source, and an
output probe is placed at the junction between the resistor and the
capacitor. The output waveform shows a desired dc voltage. However,
the input waveform fluctuates between +9.2011V and -835.622mV, and not
the required +/-10V. How can I get an input waveform of +/-10V? When I
connect the ac source to a separate (and simpler) circuit, the input
waveform shows +/-10V. Why is it that the input waveform can change
with different circuits?

Load!