I think your attached file is an Altium file (kindly correct me if I'm wrong) so I won't be able to open it. I am going to try downloading Altium though

This file ( 555+Triac.asc ) produced in LTspice simulator.
You can download LTspice for free here:
https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html

 

This file ( 555+Triac.asc ) produced in LTspice simulator.
You can download LTspice for free here:
https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html

Thank you. I will try it out. This is the implementation of your design on with Proteus. Not sure if you can pick up what I have done incorrectly? The 555 Timer is not producing any output for me

View attachment allabout.jpg

 

Thank you. I will try it out. This is the implementation of your design on with Proteus. Not sure if you can pick up what I have done incorrectly? The 555 Timer is not producing any output for me

Zip and send your .pdsprj file

 

Zip and send your .pdsprj file

Thank you for your help

 

I used R3 to complete the astable configuration as suggested in # 22 of U4.

Sorry, I should have been more clear. I was referring to R3 in post #29, where U4 is configured as a monostable.

ak

 

Done:

 

Sorry, I should have been more clear. I was referring to R3 in post #29, where U4 is configured as a monostable.

ak

No worries. I should have been more concise. I intended for U4 to be configured as astable because #22 suggested this

 

Done
View attachment 267528

Thank you again, I see where I went wrong. I'm having a hard time understanding your zero crossing detector design. Do you mind giving a brief explanation?

 

I'm having a hard time understanding your zero crossing detector design. Do you mind giving a brief explanation?

Simple circuit.
Q1 is turned ON during almost all time of every half-period because of current from line through resistors R1, R2, R3 and B-E of Q1.
Turned ON Q1 shunts "gate" of "SCR". Transistors Q2+Q3 are very sensitive (small part of 1μA) analog of SCR.
Capacitor C1 is charging during 1/2 of every half-period through diode D1 up to 13V.
When line voltage becomes 0V, transistor Q1 turns OFF for short (about 20 microseconds) time, so current from 13V goes through R5 in "gate" of "SCR" (base of NPN transistor).
"SCR" turns ON, capacitor C1 instantly discharges through "SCR", resistor R6 and LED of opto-couple.
Amplitude of LED's current is 40 - 45 mA, duration of current pulse is about 8μs at level 0.5.
More see here.

 

Simple circuit.
Q1 is turned ON during almost all time of every half-period because of current from line through resistors R1, R2, R3 and B-E of Q1.
Turned ON Q1 shunts "gate" of "SCR". Transistors Q2+Q3 are very sensitive (small part of 1μA) analog of SCR.
Capacitor C1 is charging during 1/2 of every half-period through diode D1 up to 13V.
When line voltage becomes 0V, transistor Q1 turns OFF for short (about 20 microseconds) time, so current from 13V goes through R5 in "gate" of "SCR" (base of NPN transistor).
"SCR" turns ON, capacitor C1 instantly discharges through "SCR", resistor R6 and LED of opto-couple.
Amplitude of LED's current is 40 - 45 mA, duration of current pulse is about 8μs at level 0.5.
More see here.

Hi Danko. Just want to check something. So I can't open your Proteus file as I have the older 8.9 version but from what I could see from your screenshot, you changed from a power rail to a 12V DC Generator. So I did the same in my file but I don't know if there's an error on my side. The voltage across the lamp when the whole sine wave is driving it is capped at 160V, similar to my previous circuit in #23. Should it not be at 230V or am I completely missing something?

 

Hi Danko. Just want to check something. So I can't open your Proteus file as I have the older 8.9 version but from what I could see from your screenshot, you changed from a power rail to a 12V DC Generator. So I did the same in my file but I don't know if there's an error on my side. The voltage across the lamp when the whole sine wave is driving it is capped at 160V, similar to my previous circuit in #23. Should it not be at 230V or am I completely missing something?

Follow these instructions:
1. Open file from your archive test1.zip in Proteus.
2. Change voltage of VCC from 5V to 12V.
3. Change voltage of INPUT from 8V to 5V.
4. Change photocoupler from 4N25 to PC817.
5. Change voltage of V1 from VA=230 to VA=325 (if you want 230V to be measured).
6. Connect oscilloscope to circuit, run animation, and see curves.

 

Follow these instructions:
1. Open file from your archive test1.zip in Proteus.
2. Change voltage of VCC from 5V to 12V.
3. Change voltage of INPUT from 8V to 5V.
4. Change photocoupler from 4N25 to PC817.
5. Change voltage of V1 from VA=230 to VA=325 (if you want 230V to be measured).
6. Connect oscilloscope to circuit, run animation, and see curves.
View attachment 267689

Thank you. I implemented 1-4 and I forgot to mention that I also changed to PC817 in #50. Is there a way to keep VA at 230V as I am building this using mains voltage and I don't have access to a transformer?

 

Thank you. I implemented 1-4 and I forgot to mention that I also changed to PC817 in #50. Is there a way to keep VA at 230V as I am building this using mains voltage and I don't have access to a transformer?

Your mains RMS voltage is 230 V. Amplitude voltage VA of your mains is Vrms*√2 = 230*1.414 ≈ 325 V.

 

Your mains RMS voltage is 230 V. Amplitude voltage VA of your mains is Vrms*√2 = 230*1.414 ≈ 325 V.

Thank you once again. I am new to Proteus and didn't realize the VSINE uses the Peak Voltage. Sorry for going silent for so long, I was trying to figure out how to adapt the control signal from a 5V range to 8V range. I managed to this and it works perfectly now. However, do mind explaining your use for R9 and C3? I am finding it difficult to understand the effect on the duty cycle as the produced waveform (yellow) is something I have never seen before.

 

However, do mind explaining your use for R9 and C3? I am finding it difficult to understand the effect on the duty cycle as the produced waveform (yellow) is something I have never seen before.

R9 limits current through LED of U3. LED will damaged without R9.
C3 decreases duration of U3 LED current pulse (see diagram below). That dramatically increases lifetime of LED and lowers current consuming from 12V source.
Yellow waveform (here is green) represents forward voltages of U3 LED (above 0V) and D6 (below 0V).
Duty cycle equals ("Lamp ON" time) / ("Zero - Zero" time). In this example duty cycle = 5ms / 10ms = 0.5.
_____