TRIAC Phase Firing Circuit

Thread Starter

swsean

Joined Jul 8, 2019
22
Hey, I need help with my assignment.
I was required too build a Phase Firing Circuit for a aquarium heater that I am going to use in a PCB Etching Tank.
However, I wasn't able to simulate it properly using LTSpice. I am not sure where i did wrong.
Attached below is the Phase Firing circuit in LTSpice and the output.

1591015328102.png
The green line shows the 240V AC mains, red showing the pulse that I send to the optocoupler (MOC3021) and blue line shows the output (voltage across the 100Ω resistor)

The MOC3021 optocoupler and Q8004L4 TRIAC was imported.

Library File for MOC3021 Optocoupler:
* OPTO TRIAC
* Helmut Sennewald 8/10/2004
* MOC3021 I_trig=8mA
* D+ D- MT2 MT1
.SUBCKT MOC3021 AN CT T2 T1
.PARAM Itrig=8m
.PARAM RH1=20k
.PARAM RH2=20k
.PARAM RH3=16.7k
Q2 vb1 vb1p vd1 0 PNP1
Q1 vb1p vb1 4 0 NPN1
R3 vb1 4 {RH2}
D1 1 2 DL
R1 ctrl1 4 1
C1 ctrl1 4 10
R2 ctrl1 vb1 {RH1}
R4 vd1 vb1p {RH3}
B1 ctrl1 4 I=-500*I(D1)*3m/Itrig
R6 vd2 vb2 {RH2}
D3 vd2 3 D1
Q3 vb2 vb2p 4 0 PNP1
Q4 vb2p vb2 vd2 0 NPN1
E1 vd2 N001 ctrl1 4 -1
R5 N001 vb2 {RH1}
R7 vb2p 4 {RH3}
D2 3 vd1 D1
R34 3 4 100MEG
.MODEL PNP1 PNP(Is=1e-15 BF=10 Cjc=10p Cje=20p Tf=0.1u Ise=1e-12)
.MODEL NPN1 NPN(Is=1e-15 BF=10 Cjc=10p Cje=20p Tf=0.1u Ise=1e-12)
.MODEL D1 D(Is=0.1u Rs=2 Cj0=50p) .MODEL DL D(Is=1e-20 Rs=5)
.ENDS
Library File for Q8004L4 TRIAC:
*SRC=Q8004L4;Q8004L4;TRIACS;TECCOR;800V 4A
*SYM=TRIAC
.SUBCKT Q8004L4   T2 G  T1
*     TERMINALS: MT2 G MT1
QN1  5 4 3  NOUT OFF
QN2 11 6 7  NOUT OFF
QP1 6 11 3  POUT OFF
QP2  4 5 7  POUT OFF
DF  4  5  DZ OFF
DR  6 11  DZ OFF
RF  4 6  16MEG
RT2 1 7  0.123
RH  7 6  17.5
RGP 8 3  24
RG  2 8  11.6
RS  8 4  2.4
DN  9 2  DIN OFF
RN  9 3  12.2
GNN  6 7 9 3 0.166
GNP  4 5 9 3 0.352
DP 2 10  DIP OFF
RP 10 3  7.12
GP  7 6 10 3 0.112
.MODEL DIN  D (IS=229F)
.MODEL DIP  D (IS=229F N=1.19)
.MODEL DZ   D (IS=229F N=1.5 IBV=50U BV=800)
.MODEL POUT PNP (IS=229F BF=5 CJE=1.68N TF=76.5U)
.MODEL NOUT NPN (IS=229F BF=20 CJE=1.68N CJC=335P TF=5.1U)
.ENDS
Please help me
 

Thread Starter

swsean

Joined Jul 8, 2019
22
hi sean,
You seem to have a problem with your opto coupler.
For comparison this is your circuit with different Opto and Triac
E
Does that mean that the library for the MOC3021 is incorrect?
Or that the MOC3021 optocoupler is unsuitable?
 

Thread Starter

swsean

Joined Jul 8, 2019
22
I've tried the MOC3023 but the same results appears again
May I know where you downloaded the Library for the TRIACs?
hi sean,
You seem to have a problem with your opto coupler.
For comparison this is your circuit with different Opto and Triac
E
 
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