TRIAC Control by PWM firing signal

Version 4
SHEET 1 2956 904
WIRE 400 64 288 64
WIRE 672 64 624 64
WIRE 1008 64 672 64
WIRE 288 80 288 64
WIRE 1008 128 1008 64
WIRE 400 144 352 144
WIRE 704 144 624 144
WIRE 864 144 704 144
WIRE 704 160 704 144
WIRE 288 176 288 160
WIRE 352 176 352 144
WIRE 864 176 864 144
WIRE 240 224 208 224
WIRE 352 224 320 224
WIRE 400 224 352 224
WIRE 656 224 624 224
WIRE 208 256 208 224
WIRE 656 256 656 224
WIRE 704 256 704 240
WIRE 704 256 656 256
WIRE 352 272 352 224
WIRE 704 272 704 256
WIRE 864 288 864 256
WIRE 1008 288 1008 208
WIRE 208 368 208 336
WIRE 352 368 352 352
WIRE 704 368 704 352
FLAG 352 176 0
FLAG 704 368 0
FLAG 672 64 VOUT
FLAG 864 288 0
FLAG 352 368 0
FLAG 288 176 0
FLAG 208 368 0
FLAG 1008 288 0
SYMBOL res 336 256 R0
SYMATTR InstName RSET
SYMATTR Value 10.2
SYMBOL res 688 144 R0
SYMATTR InstName R1
SYMATTR Value 976k
SYMBOL res 688 256 R0
SYMATTR InstName R2
SYMATTR Value 102k
SYMBOL voltage 864 160 R0
SYMATTR InstName V+
SYMATTR Value 5.0
SYMBOL SpecialFunctions\\LTC6993-1 512 144 R0
SYMATTR InstName U1
SYMBOL res 336 208 R90
WINDOW 0 -2 125 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName RVCO
SYMATTR Value 10.2
SYMBOL voltage 208 240 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
WINDOW 3 24 96 Invisible 2
WINDOW 0 40 58 Left 2
SYMATTR Value 0.5
SYMATTR InstName VC
SYMBOL voltage 288 64 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
WINDOW 3 24 96 Invisible 2
WINDOW 0 41 39 Left 2
SYMATTR Value PWL(0 0.00 9.0m 0 10m 5 11m 0 19m 0 20m 5 21m 0)
SYMATTR InstName TRIG1
SYMBOL res 992 112 R0
SYMATTR InstName R3
SYMATTR Value 1k
TEXT 480 304 Left 2 !.tran 50m
TEXT -272 40 Left 2 ;Ideal
TEXT -88 40 Left 2 ;Actual
TEXT -448 80 Left 2 ;TPULSE
TEXT -272 80 Left 2 ;1.00m to 10.0m
TEXT -88 80 Left 2 ; to
TEXT -448 120 Left 2 ;VC
TEXT -272 120 Left 2 ;0.00 to 1.00
TEXT -88 120 Left 2 ;0.00 to 1.00
TEXT -448 152 Left 2 ;RSET
TEXT -88 152 Left 2 ;10.2
TEXT -448 184 Left 2 ;RVCO
TEXT -88 184 Left 2 ;10.2
TEXT -448 224 Left 2 ;DIVCODE
TEXT -88 224 Left 2 ;NaN
TEXT -448 256 Left 2 ;NDIV
TEXT -88 256 Left 2 ;NaN
TEXT -448 288 Left 2 ;FMASTER
TEXT -88 288 Left 2 ; to Hz
TEXT -448 328 Left 2 ;ISET
TEXT -88 328 Left 2 ;98.0m to 196mA
TEXT -448 360 Left 2 ;TSTARTUP
TEXT -88 360 Left 2 ; to s
TEXT 608 672 Left 2 ;LINEAR TECHNOLOGY CORPORATION
TEXT 608 720 Left 2 ;LTC6993 Low Frequency Silicon Oscillator
TEXT 608 840 Left 1 ;Generated By LTC6993 Web Tool\nTue Jun 09 2020 15:07:11 GMT+0200 (Mitteleuropäische Sommerzeit)\nCopyright (C) 2020 Linear Technology Corporation
TEXT 128 672 Left 2 ;CUSTOMER NOTICE
TEXT 128 704 Left 1 ;If a symbol is not found, please update the symbols by selecting\nthe Sync Release command from the Tools menu in the Windows\nversion, or by clicking the Model Update button in the Operation\nTab in the Control Panel in the Mac version.\nIt remains the customer's responsibility to verify proper and\nreliable operation in the actual application. Component\nsubstitution and printed circuit board layout may significantly\naffect circuit performance or reliability.\nContact your local sales representative for assistance.
TEXT -496 672 Left 2 ;INSTRUCTIONS
TEXT -496 704 Left 2 ;Run the transient simulation, then plot VOUT and VCO\nto verify the the frequency.\n
TEXT 208 480 Left 2 ;The LTC6993-1/ LTC6993-3 will ignore additional trigger inputs \nuntil the output pulse has terminated.
TEXT 1168 -176 Left 2 ;we are developing a driver stage for feeder. ( device: 230 VAC;50 Hz )\nthis should be performed by cutting  a leading or trailing edge of the ac power.\nFurthermore a TRIAC and the zero detect signal is used. The procedure ist as following:\nThe zero signal is detected => the voltage controlled PWM will be started to fire the triac.\nI have done a LTSPICE simulation with the LTC6993-1 (non retriggered ) and expect the start of tehe PWM after the rising edge of the zerro detect signal.\nBut the signal is  not as expected. !\nkinds regard \n                   bernd\nis there a possibility to send the LTSPICE asc file
LINE Normal 320 144 320 144 2
LINE Normal 336 272 336 272 2
LINE Normal -270 58 -170 58
LINE Normal -90 58 10 58
LINE Normal 160 144 160 144 2
RECTANGLE Normal -500 -228 1100 900
RECTANGLE Normal 1100 820 596 692
RECTANGLE Normal 1100 692 596 644
RECTANGLE Normal 596 900 108 644
RECTANGLE Normal 108 900 -500 644
we are developing a driver stage for feeder. ( device: 230 VAC;50 Hz )
this should be performed by cutting  a leading or trailing edge of the ac power.
Furthermore a TRIAC and the zero detect signal is used. The procedure ist as following:
The zero signal is detected => the voltage controlled PWM will be started to fire the triac.
I have done a LTSPICE simulation with the LTC6993-1 (non retriggered ) and expect the start of tehe PWM after the rising edge of the zerro detect signal.
But the signal is  not as expected. !
kinds regard
                   bernd

attached the LTSPICE asc file

  • 0
    •  Analog Employees 
    on Jun 9, 2020 11:09 PM 5 months ago

    Bernd,

    It is not clear to me exactly what you are trying to achieve here. It does appear that you are looking for a voltage tunable one-shot with a range of 1ms to 10ms. Unfortunately, this range does not quite work with the LTC6993-1. Each DIVCODE allows for a 16 to 1 tuning range, but there is not a range that fits your requirement right. This is why the webtool gave an odd result in the "actual" column. The closest that this part can cover with simple voltage tuning is with DIVCODE=3 (or 12) which covers 512us to 8.192ms. See Table 1 on page 13 of the data sheet. To cover a wider range of pulse widths requires changing the DIVCODE by changing R1 or R2 to shift to a new range of pulse widths. If you need complete analog voltage tunable pulse width solution the LTC6993-1 can not quite achieve this exact range.