Timeline for Struggling to understand zero cross detecting circuit
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 23, 2021 at 19:27 | comment | added | D.A.S. | I once designed a simple offline ZCS using an XOR Gate for an 8 Channel Triac 1kW lamp sequencer chaser back in the 70's that looked somthing like this with 1% duty cycle 1% after the ZCS for adequate Triac gate current yet very close to 0V. I used a tiny pulse transformer to trigger the Triacs rather than RC. using this ZCS to enable a sequencer. tinyurl.com/ydossxve | |
| Oct 23, 2021 at 18:17 | comment | added | D.A.S. | However C2 < 5nF lightly reduces PW50 pulse width with value of ZCS output negative pulse, yet not enough to call it precise. | |
| Oct 23, 2021 at 17:58 | comment | added | D.A.S. | I agree with; IncreasingR1/R2 which reduces Pwr 50% especially for 240V 50Hz from 1/4W. Some differences in PW50 of ZCS pulse exist between 120V/60Hz and 240/50Hz. R3 is OK and R4 is OK only if using a Darlington but in any case does not reduce Pwr at all, due to low duty cycle. So original is OK. However C2 = 1nF or less has no effect on ZCS being centred or lagging, but > 6n8 will lag on 60Hz 120V+560K(2) enough to start ZCS after 0Vac and shift with increasing values while duty cycle is 10%. tinyurl.com/yhubcfvm | |
| Oct 23, 2021 at 17:49 | comment | added | D.A.S. | For future historical reference, I verified your design choices and agree with most except two. | |
| May 11, 2020 at 14:27 | review | Late answers | |||
| May 11, 2020 at 15:21 | |||||
| May 11, 2020 at 14:16 | review | First posts | |||
| May 12, 2020 at 19:36 | |||||
| May 11, 2020 at 14:12 | history | answered | Wolfgang | CC BY-SA 4.0 |