hi
Pleased to hear it is finally working as you expect.

Good luck with the project.
E

 

Thank you.
Now it works perfectly, with S4025L.
SCR Gate is switched at the Zero crossing of the Mains signal, as expected.

I have downloaded BTW69 model from ST website, it seems this model has issue.

Thank you again.
View attachment 287668

@ericgibbs

Hello Eric,

I have assembled real circuit with BTW69. The circuit operates perfectly, but the issue is that BTW69 dissipates heat, so I need huge heat sink for two SCR components. Could you please introduce substitute component with less heat dissipation. Also are you able to offer another modern approach to control electrical heater of 2000W-2500W range.

Thank you.

Thank you.
Now it works perfectly, with S4025L.
SCR Gate is switched at the Zero crossing of the Mains signal, as expected.

I have downloaded BTW69 model from ST website, it seems this model has issue.

Thank you again.
View attachment 287668

 

Hi i99,
I will look the circuit over and reply.
E

 

Hi i99,
The BTW68 SCR seems to have a problem in displaying the correct results when simulating into a 15R Load?

For comparison, I have used the S6020L SCR which shows a 15R load has a peak current of approx 19.4Amps from a 220V RMS supply, which is approx 311Vpeak, ie: 311V/15R =19.44Amps.

Compare that figure with 1.8Amps when using a BTW68 SCR.

Note the dissipation Wattage for the two SCR types.

Can you confirm that the Rload is 15R and the local Voltage RMS is 220v?

E

 

Hi ericgibbs,

Thank you for your reply.
Yes, Rload is 15R and local line voltage RMS is 220V.

Best regards,
Lhagva

Hi i99,
The BTW68 SCR seems to have a problem in displaying the correct results when simulating into a 15R Load?

For comparison, I have used the S6020L SCR which shows a 15R load has a peak current of approx 19.4Amps from a 220V RMS supply, which is approx 311Vpeak, ie: 311V/15R =19.44Amps.

Compare that figure with 1.8Amps when using a BTW68 SCR.

Note the dissipation Wattage for the two SCR types.

Can you confirm that the Rload is 15R and the local Voltage RMS is 220v?

E
View attachment 306093

 

H i99,
The avg dissipation in each SCR should be approx 7Watts as per this simulation.
For 220Vac RMS, with a 15R +1R Load that is approx 13.6Amps.

How are you driving the opto-coupler input?

E