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Kill LED lamp flicker

Started by Mike Monett VE3BTI ●September 8, 2023
I recently changed the overhead fluorescent lamps for LED replacements. 

Very soon, I noticed they were flickering a lot more the the old 
fluorescents. 

They flicker on the slightest line disturbance, from someone turning on a 
microwave to who knows what outside the building. It turns out the 
bandwidth of LEDs is much higher than gas lamps. Good to know if you're in 
the spying business, but not good in the shop.

I studied various methods of supplying clean power, from LifePO4 batteries 
to my own solar array. Very expensive, and can't avoid batteries.

I settled on a brute force attack, using a dimmer and huge capacitors. The 
dimmer is needed as a PWM to reduce the rectified line voltage from 160 
volts down to 125 volts. The dimmer also allows to dim the LEDs to arrive 
at a more comfortable illumination. They are very bright.

The lED lamps contain their own bridge rectifier to convert the AC line 
voltage to DC to drive the lamps.

There is one trick in the circuit that is of note, and is why I am posting 
the circuit here.

It is necessary to break the dimmer AC line between the delay pot and the 
triac to insert a 10 ohm resistor. The resistor cuts down on the surge 
current during startup, but it causes a drop in line voltage. If this drop 
is applied to the delay pot, the circuit goes haywire during startup.

Note the 1N4007 diodes are replaced by a regular bridge rectifier with 
suitable ratings. It is easier to model using 1N4007s than trying to find a 
bridge rectifier in LTspice.

The circuit has been tested on LTspice IV and XII. I will never run QSpice 
since is requires MS 10-11 and 64 bits. I got off the Microsoft merry-go-
round at Win7, and I am perfectly content to stay there.

From past experience it may be necessary to fiddle with the Model 
statements to get the program to load in LTspice. The line wrap in the 
newsgroup creates havoc on LTspice.

Here's the ASC file:

Version 4
SHEET 1 1684 680
WIRE 176 16 -16 16
WIRE 224 16 176 16
WIRE 368 16 304 16
WIRE 432 16 368 16
WIRE 480 16 432 16
WIRE 592 16 544 16
WIRE 368 32 368 16
WIRE 176 64 176 16
WIRE -16 112 -16 16
WIRE 368 128 368 112
WIRE 464 128 368 128
WIRE 480 128 464 128
WIRE 592 128 592 16
WIRE 592 128 544 128
WIRE 624 128 592 128
WIRE 640 128 624 128
WIRE 656 128 640 128
WIRE 752 128 736 128
WIRE 864 128 752 128
WIRE 368 144 368 128
WIRE 640 160 640 128
WIRE 864 160 864 128
WIRE 752 176 752 128
WIRE 176 208 176 144
WIRE 224 208 176 208
WIRE 256 208 224 208
WIRE 176 224 176 208
WIRE 432 272 432 16
WIRE 480 272 432 272
WIRE 592 272 544 272
WIRE 640 272 640 240
WIRE 640 272 592 272
WIRE 720 272 640 272
WIRE 752 272 752 240
WIRE 752 272 720 272
WIRE 864 272 864 240
WIRE 864 272 752 272
WIRE -16 304 -16 192
WIRE 176 304 176 288
WIRE 176 304 -16 304
WIRE 368 304 368 208
WIRE 368 304 176 304
WIRE -16 320 -16 304
WIRE 464 352 464 128
WIRE 480 352 464 352
WIRE 592 352 592 272
WIRE 592 352 544 352
FLAG -16 320 0
FLAG 368 16 A
FLAG 224 208 VC1
FLAG 752 128 C
FLAG 720 272 D
FLAG 368 128 B
FLAG 624 128 E
SYMBOL misc\\DIAC 320 176 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 64 32 VTop 2
WINDOW 123 92 32 VTop 2
SYMATTR InstName Q1
SYMATTR Value2 VK=30
SYMBOL voltage -16 96 R0
WINDOW 0 10 -1 Left 2
WINDOW 3 -65 137 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value SINE(0 166 60 0 0 0 20)
SYMBOL res 160 160 M180
WINDOW 0 36 76 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName R1
SYMATTR Value 200k
SYMBOL cap 160 224 R0
SYMATTR InstName C1
SYMATTR Value .062u
SYMBOL misc\\TRIAC 336 144 R0
SYMATTR InstName U1
SYMBOL diode 544 0 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D1
SYMATTR Value 1N4007
SYMBOL diode 544 112 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D2
SYMATTR Value 1N4007
SYMBOL diode 480 288 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D3
SYMATTR Value 1N4007
SYMBOL diode 480 368 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D4
SYMATTR Value 1N4007
SYMBOL res 624 144 R0
SYMATTR InstName R2
SYMATTR Value 230
SYMBOL cap 736 176 R0
SYMATTR InstName C2
SYMATTR Value 1640uf
SYMBOL res 752 112 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 0.1
SYMBOL res 352 16 R0
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL res 320 0 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 10
SYMBOL res 848 144 R0
SYMATTR InstName R6
SYMATTR Value 100k
TEXT 40 -48 Left 2 !.tran 0 500ms 0 10u
TEXT -376 280 Left 2 !.subckt DIAC T1 T2\n* default parameters\n.param RS=
10 ; series resistance\n.param VK=20 ; breakdown voltage\nQ1 N002 N001 T2 0 
PN\nQ2 N001 N002 N005 0 NP\nR1 N002 N004 {20K*(VK-1)}\nR2 N004 T2 9.5K\nR3 
N002 N005 9.5K\nQ3 N004 N003 N005 0 PN\nQ4 N003 N004 T2 0 NP\nR4 T1 N005 
{RS}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP Cjc=10p Cje=10p\n.ends 
DIAC
TEXT -376 16 Left 2 !.subckt TRIAC MT2 G MT1\n.param R=10K\nQ1 N001 G MT1 0 
NP\nQ2 N001 N002 MT2 0 NP\nQ3 N002 N001 MT1 0 PN\nQ4 G N001 MT2 0 PN\nR1 
MT2 N002 {R}\nR2 G MT1 {R}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP 
Cjc=10p Cje=10p\n.ends TRIAC
TEXT 40 -80 Left 2 ;'DIAC TRIAC Light Dimmer Step RDim
TEXT 64 336 Left 2 ;200e3*.062e-6 = 0.0124 seconds
TEXT -56 432 Left 2 !.model 1N4007 D(Is=14.11n N=1.984 Rs=33.89m Ikf=94.81 
Xti=3 Eg=1.11 Cjo=25.89p \n+M=.44 Vj=.3245 Fc=.5 Bv=1500 Ibv=10u Tt=5.7u 
Iave=1A Vpk=1500 mfg=Motorola type=silicon)
TEXT 632 312 Left 2 ;100e3*1540e-6= 154 seconds

The PLT file

[Transient Analysis]
{
   Npanes: 2
   Active Pane: 1
   {
      traces: 3 {524293,0,"V(d,c)"} {524294,0,"V(d,e)"} {34603012,1,"I
(R3)"}
      X: ('m',0,0,0.05,0.5)
      Y[0]: (' ',0,0,10,130)
      Y[1]: (' ',0,-4,2,22)
      Volts: (' ',0,0,0,0,10,130)
      Amps: (' ',0,0,0,-4,2,22)
      Log: 0 0 0
      GridStyle: 1
   },
   {
      traces: 2 {524291,0,"V(b)"} {524290,0,"V(a)"}
      X: ('m',0,0,0.05,0.5)
      Y[0]: (' ',0,-180,30,180)
      Y[1]: (' ',0,1e+308,3,-1e+308)
      Volts: (' ',0,0,0,-180,30,180)
      Log: 0 0 0
      GridStyle: 1
   }
}


-- 
MRM
Reply by piglet ●September 8, 20232023-09-08
On 08/09/2023 9:10 am, Mike Monett VE3BTI wrote:

> I recently changed the overhead fluorescent lamps for LED replacements.
> 
> Very soon, I noticed they were flickering a lot more the the old
> fluorescents.
> 
> They flicker on the slightest line disturbance, from someone turning on a
> microwave to who knows what outside the building. It turns out the
> bandwidth of LEDs is much higher than gas lamps. Good to know if you're in
> the spying business, but not good in the shop.
> 
> I studied various methods of supplying clean power, from LifePO4 batteries
> to my own solar array. Very expensive, and can't avoid batteries.
> 
> I settled on a brute force attack, using a dimmer and huge capacitors. The
> dimmer is needed as a PWM to reduce the rectified line voltage from 160
> volts down to 125 volts. The dimmer also allows to dim the LEDs to arrive
> at a more comfortable illumination. They are very bright.
> 
> The lED lamps contain their own bridge rectifier to convert the AC line
> voltage to DC to drive the lamps.
> 
> There is one trick in the circuit that is of note, and is why I am posting
> the circuit here.
> 
> It is necessary to break the dimmer AC line between the delay pot and the
> triac to insert a 10 ohm resistor. The resistor cuts down on the surge
> current during startup, but it causes a drop in line voltage. If this drop
> is applied to the delay pot, the circuit goes haywire during startup.
> 
> Note the 1N4007 diodes are replaced by a regular bridge rectifier with
> suitable ratings. It is easier to model using 1N4007s than trying to find a
> bridge rectifier in LTspice.
> 
> The circuit has been tested on LTspice IV and XII. I will never run QSpice
> since is requires MS 10-11 and 64 bits. I got off the Microsoft merry-go-
> round at Win7, and I am perfectly content to stay there.
> 
>  From past experience it may be necessary to fiddle with the Model
> statements to get the program to load in LTspice. The line wrap in the
> newsgroup creates havoc on LTspice.
> 
> Here's the ASC file:
> 
> Version 4
> SHEET 1 1684 680
> WIRE 176 16 -16 16
> WIRE 224 16 176 16
> WIRE 368 16 304 16
> WIRE 432 16 368 16
> WIRE 480 16 432 16
> WIRE 592 16 544 16
> WIRE 368 32 368 16
> WIRE 176 64 176 16
> WIRE -16 112 -16 16
> WIRE 368 128 368 112
> WIRE 464 128 368 128
> WIRE 480 128 464 128
> WIRE 592 128 592 16
> WIRE 592 128 544 128
> WIRE 624 128 592 128
> WIRE 640 128 624 128
> WIRE 656 128 640 128
> WIRE 752 128 736 128
> WIRE 864 128 752 128
> WIRE 368 144 368 128
> WIRE 640 160 640 128
> WIRE 864 160 864 128
> WIRE 752 176 752 128
> WIRE 176 208 176 144
> WIRE 224 208 176 208
> WIRE 256 208 224 208
> WIRE 176 224 176 208
> WIRE 432 272 432 16
> WIRE 480 272 432 272
> WIRE 592 272 544 272
> WIRE 640 272 640 240
> WIRE 640 272 592 272
> WIRE 720 272 640 272
> WIRE 752 272 752 240
> WIRE 752 272 720 272
> WIRE 864 272 864 240
> WIRE 864 272 752 272
> WIRE -16 304 -16 192
> WIRE 176 304 176 288
> WIRE 176 304 -16 304
> WIRE 368 304 368 208
> WIRE 368 304 176 304
> WIRE -16 320 -16 304
> WIRE 464 352 464 128
> WIRE 480 352 464 352
> WIRE 592 352 592 272
> WIRE 592 352 544 352
> FLAG -16 320 0
> FLAG 368 16 A
> FLAG 224 208 VC1
> FLAG 752 128 C
> FLAG 720 272 D
> FLAG 368 128 B
> FLAG 624 128 E
> SYMBOL misc\\DIAC 320 176 R90
> WINDOW 0 0 32 VBottom 2
> WINDOW 3 64 32 VTop 2
> WINDOW 123 92 32 VTop 2
> SYMATTR InstName Q1
> SYMATTR Value2 VK=30
> SYMBOL voltage -16 96 R0
> WINDOW 0 10 -1 Left 2
> WINDOW 3 -65 137 Left 2
> WINDOW 123 0 0 Left 2
> WINDOW 39 0 0 Left 2
> SYMATTR InstName V1
> SYMATTR Value SINE(0 166 60 0 0 0 20)
> SYMBOL res 160 160 M180
> WINDOW 0 36 76 Left 2
> WINDOW 3 36 40 Left 2
> SYMATTR InstName R1
> SYMATTR Value 200k
> SYMBOL cap 160 224 R0
> SYMATTR InstName C1
> SYMATTR Value .062u
> SYMBOL misc\\TRIAC 336 144 R0
> SYMATTR InstName U1
> SYMBOL diode 544 0 R90
> WINDOW 0 0 32 VBottom 2
> WINDOW 3 32 32 VTop 2
> SYMATTR InstName D1
> SYMATTR Value 1N4007
> SYMBOL diode 544 112 R90
> WINDOW 0 0 32 VBottom 2
> WINDOW 3 32 32 VTop 2
> SYMATTR InstName D2
> SYMATTR Value 1N4007
> SYMBOL diode 480 288 R270
> WINDOW 0 32 32 VTop 2
> WINDOW 3 0 32 VBottom 2
> SYMATTR InstName D3
> SYMATTR Value 1N4007
> SYMBOL diode 480 368 R270
> WINDOW 0 32 32 VTop 2
> WINDOW 3 0 32 VBottom 2
> SYMATTR InstName D4
> SYMATTR Value 1N4007
> SYMBOL res 624 144 R0
> SYMATTR InstName R2
> SYMATTR Value 230
> SYMBOL cap 736 176 R0
> SYMATTR InstName C2
> SYMATTR Value 1640uf
> SYMBOL res 752 112 R90
> WINDOW 0 0 56 VBottom 2
> WINDOW 3 32 56 VTop 2
> SYMATTR InstName R3
> SYMATTR Value 0.1
> SYMBOL res 352 16 R0
> SYMATTR InstName R4
> SYMATTR Value 1k
> SYMBOL res 320 0 R90
> WINDOW 0 0 56 VBottom 2
> WINDOW 3 32 56 VTop 2
> SYMATTR InstName R5
> SYMATTR Value 10
> SYMBOL res 848 144 R0
> SYMATTR InstName R6
> SYMATTR Value 100k
> TEXT 40 -48 Left 2 !.tran 0 500ms 0 10u
> TEXT -376 280 Left 2 !.subckt DIAC T1 T2\n* default parameters\n.param RS=
> 10 ; series resistance\n.param VK=20 ; breakdown voltage\nQ1 N002 N001 T2 0
> PN\nQ2 N001 N002 N005 0 NP\nR1 N002 N004 {20K*(VK-1)}\nR2 N004 T2 9.5K\nR3
> N002 N005 9.5K\nQ3 N004 N003 N005 0 PN\nQ4 N003 N004 T2 0 NP\nR4 T1 N005
> {RS}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP Cjc=10p Cje=10p\n.ends
> DIAC
> TEXT -376 16 Left 2 !.subckt TRIAC MT2 G MT1\n.param R=10K\nQ1 N001 G MT1 0
> NP\nQ2 N001 N002 MT2 0 NP\nQ3 N002 N001 MT1 0 PN\nQ4 G N001 MT2 0 PN\nR1
> MT2 N002 {R}\nR2 G MT1 {R}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP
> Cjc=10p Cje=10p\n.ends TRIAC
> TEXT 40 -80 Left 2 ;'DIAC TRIAC Light Dimmer Step RDim
> TEXT 64 336 Left 2 ;200e3*.062e-6 = 0.0124 seconds
> TEXT -56 432 Left 2 !.model 1N4007 D(Is=14.11n N=1.984 Rs=33.89m Ikf=94.81
> Xti=3 Eg=1.11 Cjo=25.89p \n+M=.44 Vj=.3245 Fc=.5 Bv=1500 Ibv=10u Tt=5.7u
> Iave=1A Vpk=1500 mfg=Motorola type=silicon)
> TEXT 632 312 Left 2 ;100e3*1540e-6= 154 seconds
> 
> The PLT file
> 
> [Transient Analysis]
> {
>     Npanes: 2
>     Active Pane: 1
>     {
>        traces: 3 {524293,0,"V(d,c)"} {524294,0,"V(d,e)"} {34603012,1,"I
> (R3)"}
>        X: ('m',0,0,0.05,0.5)
>        Y[0]: (' ',0,0,10,130)
>        Y[1]: (' ',0,-4,2,22)
>        Volts: (' ',0,0,0,0,10,130)
>        Amps: (' ',0,0,0,-4,2,22)
>        Log: 0 0 0
>        GridStyle: 1
>     },
>     {
>        traces: 2 {524291,0,"V(b)"} {524290,0,"V(a)"}
>        X: ('m',0,0,0.05,0.5)
>        Y[0]: (' ',0,-180,30,180)
>        Y[1]: (' ',0,1e+308,3,-1e+308)
>        Volts: (' ',0,0,0,-180,30,180)
>        Log: 0 0 0
>        GridStyle: 1
>     }
> }
> 
> 


What do you use the waste heat in R5 for, boiling water for tea?

piglet
Reply by piglet ●September 8, 20232023-09-08
On 08/09/2023 11:18 am, piglet wrote:

> On 08/09/2023 9:10 am, Mike Monett VE3BTI wrote:
>> I recently changed the overhead fluorescent lamps for LED replacements.
>>
>> Very soon, I noticed they were flickering a lot more the the old
>> fluorescents.
>>
>> They flicker on the slightest line disturbance, from someone turning on a
>> microwave to who knows what outside the building. It turns out the
>> bandwidth of LEDs is much higher than gas lamps. Good to know if 
>> you're in
>> the spying business, but not good in the shop.
>>
>> I studied various methods of supplying clean power, from LifePO4 
>> batteries
>> to my own solar array. Very expensive, and can't avoid batteries.
>>
>> I settled on a brute force attack, using a dimmer and huge capacitors. 
>> The
>> dimmer is needed as a PWM to reduce the rectified line voltage from 160
>> volts down to 125 volts. The dimmer also allows to dim the LEDs to arrive
>> at a more comfortable illumination. They are very bright.
>>
>> The lED lamps contain their own bridge rectifier to convert the AC line
>> voltage to DC to drive the lamps.
>>
>> There is one trick in the circuit that is of note, and is why I am 
>> posting
>> the circuit here.
>>
>> It is necessary to break the dimmer AC line between the delay pot and the
>> triac to insert a 10 ohm resistor. The resistor cuts down on the surge
>> current during startup, but it causes a drop in line voltage. If this 
>> drop
>> is applied to the delay pot, the circuit goes haywire during startup.
>>
>> Note the 1N4007 diodes are replaced by a regular bridge rectifier with
>> suitable ratings. It is easier to model using 1N4007s than trying to 
>> find a
>> bridge rectifier in LTspice.
>>
>> The circuit has been tested on LTspice IV and XII. I will never run 
>> QSpice
>> since is requires MS 10-11 and 64 bits. I got off the Microsoft merry-go-
>> round at Win7, and I am perfectly content to stay there.
>>
>>  From past experience it may be necessary to fiddle with the Model
>> statements to get the program to load in LTspice. The line wrap in the
>> newsgroup creates havoc on LTspice.
>>
>> Here's the ASC file:
>>
>> Version 4
>> SHEET 1 1684 680
>> WIRE 176 16 -16 16
>> WIRE 224 16 176 16
>> WIRE 368 16 304 16
>> WIRE 432 16 368 16
>> WIRE 480 16 432 16
>> WIRE 592 16 544 16
>> WIRE 368 32 368 16
>> WIRE 176 64 176 16
>> WIRE -16 112 -16 16
>> WIRE 368 128 368 112
>> WIRE 464 128 368 128
>> WIRE 480 128 464 128
>> WIRE 592 128 592 16
>> WIRE 592 128 544 128
>> WIRE 624 128 592 128
>> WIRE 640 128 624 128
>> WIRE 656 128 640 128
>> WIRE 752 128 736 128
>> WIRE 864 128 752 128
>> WIRE 368 144 368 128
>> WIRE 640 160 640 128
>> WIRE 864 160 864 128
>> WIRE 752 176 752 128
>> WIRE 176 208 176 144
>> WIRE 224 208 176 208
>> WIRE 256 208 224 208
>> WIRE 176 224 176 208
>> WIRE 432 272 432 16
>> WIRE 480 272 432 272
>> WIRE 592 272 544 272
>> WIRE 640 272 640 240
>> WIRE 640 272 592 272
>> WIRE 720 272 640 272
>> WIRE 752 272 752 240
>> WIRE 752 272 720 272
>> WIRE 864 272 864 240
>> WIRE 864 272 752 272
>> WIRE -16 304 -16 192
>> WIRE 176 304 176 288
>> WIRE 176 304 -16 304
>> WIRE 368 304 368 208
>> WIRE 368 304 176 304
>> WIRE -16 320 -16 304
>> WIRE 464 352 464 128
>> WIRE 480 352 464 352
>> WIRE 592 352 592 272
>> WIRE 592 352 544 352
>> FLAG -16 320 0
>> FLAG 368 16 A
>> FLAG 224 208 VC1
>> FLAG 752 128 C
>> FLAG 720 272 D
>> FLAG 368 128 B
>> FLAG 624 128 E
>> SYMBOL misc\\DIAC 320 176 R90
>> WINDOW 0 0 32 VBottom 2
>> WINDOW 3 64 32 VTop 2
>> WINDOW 123 92 32 VTop 2
>> SYMATTR InstName Q1
>> SYMATTR Value2 VK=30
>> SYMBOL voltage -16 96 R0
>> WINDOW 0 10 -1 Left 2
>> WINDOW 3 -65 137 Left 2
>> WINDOW 123 0 0 Left 2
>> WINDOW 39 0 0 Left 2
>> SYMATTR InstName V1
>> SYMATTR Value SINE(0 166 60 0 0 0 20)
>> SYMBOL res 160 160 M180
>> WINDOW 0 36 76 Left 2
>> WINDOW 3 36 40 Left 2
>> SYMATTR InstName R1
>> SYMATTR Value 200k
>> SYMBOL cap 160 224 R0
>> SYMATTR InstName C1
>> SYMATTR Value .062u
>> SYMBOL misc\\TRIAC 336 144 R0
>> SYMATTR InstName U1
>> SYMBOL diode 544 0 R90
>> WINDOW 0 0 32 VBottom 2
>> WINDOW 3 32 32 VTop 2
>> SYMATTR InstName D1
>> SYMATTR Value 1N4007
>> SYMBOL diode 544 112 R90
>> WINDOW 0 0 32 VBottom 2
>> WINDOW 3 32 32 VTop 2
>> SYMATTR InstName D2
>> SYMATTR Value 1N4007
>> SYMBOL diode 480 288 R270
>> WINDOW 0 32 32 VTop 2
>> WINDOW 3 0 32 VBottom 2
>> SYMATTR InstName D3
>> SYMATTR Value 1N4007
>> SYMBOL diode 480 368 R270
>> WINDOW 0 32 32 VTop 2
>> WINDOW 3 0 32 VBottom 2
>> SYMATTR InstName D4
>> SYMATTR Value 1N4007
>> SYMBOL res 624 144 R0
>> SYMATTR InstName R2
>> SYMATTR Value 230
>> SYMBOL cap 736 176 R0
>> SYMATTR InstName C2
>> SYMATTR Value 1640uf
>> SYMBOL res 752 112 R90
>> WINDOW 0 0 56 VBottom 2
>> WINDOW 3 32 56 VTop 2
>> SYMATTR InstName R3
>> SYMATTR Value 0.1
>> SYMBOL res 352 16 R0
>> SYMATTR InstName R4
>> SYMATTR Value 1k
>> SYMBOL res 320 0 R90
>> WINDOW 0 0 56 VBottom 2
>> WINDOW 3 32 56 VTop 2
>> SYMATTR InstName R5
>> SYMATTR Value 10
>> SYMBOL res 848 144 R0
>> SYMATTR InstName R6
>> SYMATTR Value 100k
>> TEXT 40 -48 Left 2 !.tran 0 500ms 0 10u
>> TEXT -376 280 Left 2 !.subckt DIAC T1 T2\n* default parameters\n.param 
>> RS=
>> 10 ; series resistance\n.param VK=20 ; breakdown voltage\nQ1 N002 N001 
>> T2 0
>> PN\nQ2 N001 N002 N005 0 NP\nR1 N002 N004 {20K*(VK-1)}\nR2 N004 T2 
>> 9.5K\nR3
>> N002 N005 9.5K\nQ3 N004 N003 N005 0 PN\nQ4 N003 N004 T2 0 NP\nR4 T1 N005
>> {RS}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP Cjc=10p Cje=10p\n.ends
>> DIAC
>> TEXT -376 16 Left 2 !.subckt TRIAC MT2 G MT1\n.param R=10K\nQ1 N001 G 
>> MT1 0
>> NP\nQ2 N001 N002 MT2 0 NP\nQ3 N002 N001 MT1 0 PN\nQ4 G N001 MT2 0 PN\nR1
>> MT2 N002 {R}\nR2 G MT1 {R}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP
>> Cjc=10p Cje=10p\n.ends TRIAC
>> TEXT 40 -80 Left 2 ;'DIAC TRIAC Light Dimmer Step RDim
>> TEXT 64 336 Left 2 ;200e3*.062e-6 = 0.0124 seconds
>> TEXT -56 432 Left 2 !.model 1N4007 D(Is=14.11n N=1.984 Rs=33.89m 
>> Ikf=94.81
>> Xti=3 Eg=1.11 Cjo=25.89p \n+M=.44 Vj=.3245 Fc=.5 Bv=1500 Ibv=10u Tt=5.7u
>> Iave=1A Vpk=1500 mfg=Motorola type=silicon)
>> TEXT 632 312 Left 2 ;100e3*1540e-6= 154 seconds
>>
>> The PLT file
>>
>> [Transient Analysis]
>> {
>>     Npanes: 2
>>     Active Pane: 1
>>     {
>>        traces: 3 {524293,0,"V(d,c)"} {524294,0,"V(d,e)"} {34603012,1,"I
>> (R3)"}
>>        X: ('m',0,0,0.05,0.5)
>>        Y[0]: (' ',0,0,10,130)
>>        Y[1]: (' ',0,-4,2,22)
>>        Volts: (' ',0,0,0,0,10,130)
>>        Amps: (' ',0,0,0,-4,2,22)
>>        Log: 0 0 0
>>        GridStyle: 1
>>     },
>>     {
>>        traces: 2 {524291,0,"V(b)"} {524290,0,"V(a)"}
>>        X: ('m',0,0,0.05,0.5)
>>        Y[0]: (' ',0,-180,30,180)
>>        Y[1]: (' ',0,1e+308,3,-1e+308)
>>        Volts: (' ',0,0,0,-180,30,180)
>>        Log: 0 0 0
>>        GridStyle: 1
>>     }
>> }
>>
>>
> 
> What do you use the waste heat in R5 for, boiling water for tea?
> 
> piglet
> 


The model you used for 1N4007 has something very wrong - if I replace 
with one of the 600V types included with LTSpice then the crazy currents 
disappear and the circuit does more as you describe. Have you checked 
Pdiss in R4?

piglet
Reply by Don Y ●September 8, 20232023-09-08
On 9/8/2023 1:10 AM, Mike Monett VE3BTI wrote:

> I recently changed the overhead fluorescent lamps for LED replacements.
> 
> Very soon, I noticed they were flickering a lot more the the old
> fluorescents.


Use a dimmer designed for LED lighting.  They will typically
also have a "dimmer low end" than conventional dimmers.
LEDs that flicker on a simple switched line are probably of
poor quality.


> They flicker on the slightest line disturbance, from someone turning on a
> microwave to who knows what outside the building. It turns out the
> bandwidth of LEDs is much higher than gas lamps. Good to know if you're in
> the spying business, but not good in the shop.
> 
> I studied various methods of supplying clean power, from LifePO4 batteries
> to my own solar array. Very expensive, and can't avoid batteries.
> 
> I settled on a brute force attack, using a dimmer and huge capacitors. The
> dimmer is needed as a PWM to reduce the rectified line voltage from 160
> volts down to 125 volts. The dimmer also allows to dim the LEDs to arrive
> at a more comfortable illumination. They are very bright.
> 
> The lED lamps contain their own bridge rectifier to convert the AC line
> voltage to DC to drive the lamps.
Reply by Ricky ●September 8, 20232023-09-08
On Friday, September 8, 2023 at 6:56:39 AM UTC-4, Don Y wrote:

> On 9/8/2023 1:10 AM, Mike Monett VE3BTI wrote: 
> > I recently changed the overhead fluorescent lamps for LED replacements. 
> > 
> > Very soon, I noticed they were flickering a lot more the the old 
> > fluorescents.
> Use a dimmer designed for LED lighting. They will typically 
> also have a "dimmer low end" than conventional dimmers. 
> LEDs that flicker on a simple switched line are probably of 
> poor quality.


I bought an LED lighting fixture and the dimmer specified on the package as compatible.  It wasn't.  It was all crap. I contacted the manufacturer and their response was to return the product.  They don't care.  They sell you gold on the box, but crap in it. 

-- 

  Rick C.

  - Get 1,000 miles of free Supercharging
  - Tesla referral code - https://ts.la/richard11209
Reply by John Larkin ●September 8, 20232023-09-08
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
<spamme@not.com> wrote:


>I recently changed the overhead fluorescent lamps for LED replacements. 
>
>Very soon, I noticed they were flickering a lot more the the old 
>fluorescents. 
>
>They flicker on the slightest line disturbance, from someone turning on a 
>microwave to who knows what outside the building. It turns out the 
>bandwidth of LEDs is much higher than gas lamps. Good to know if you're in 
>the spying business, but not good in the shop.


I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.

Maybe you have cheap flourescent-replacement tubes. 


>
>I studied various methods of supplying clean power, from LifePO4 batteries 
>to my own solar array. Very expensive, and can't avoid batteries.
>
>I settled on a brute force attack, using a dimmer and huge capacitors. The 
>dimmer is needed as a PWM to reduce the rectified line voltage from 160 
>volts down to 125 volts. The dimmer also allows to dim the LEDs to arrive 
>at a more comfortable illumination. They are very bright.
>
>The lED lamps contain their own bridge rectifier to convert the AC line 
>voltage to DC to drive the lamps.
>
>There is one trick in the circuit that is of note, and is why I am posting 
>the circuit here.
>
>It is necessary to break the dimmer AC line between the delay pot and the 
>triac to insert a 10 ohm resistor. The resistor cuts down on the surge 
>current during startup, but it causes a drop in line voltage. If this drop 
>is applied to the delay pot, the circuit goes haywire during startup.
>
>Note the 1N4007 diodes are replaced by a regular bridge rectifier with 
>suitable ratings. It is easier to model using 1N4007s than trying to find a 
>bridge rectifier in LTspice.
>
>The circuit has been tested on LTspice IV and XII. I will never run QSpice 
>since is requires MS 10-11 and 64 bits. I got off the Microsoft merry-go-
>round at Win7, and I am perfectly content to stay there.
>
>From past experience it may be necessary to fiddle with the Model 
>statements to get the program to load in LTspice. The line wrap in the 
>newsgroup creates havoc on LTspice.
>
>Here's the ASC file:
>
>Version 4
>SHEET 1 1684 680
>WIRE 176 16 -16 16
>WIRE 224 16 176 16
>WIRE 368 16 304 16
>WIRE 432 16 368 16
>WIRE 480 16 432 16
>WIRE 592 16 544 16
>WIRE 368 32 368 16
>WIRE 176 64 176 16
>WIRE -16 112 -16 16
>WIRE 368 128 368 112
>WIRE 464 128 368 128
>WIRE 480 128 464 128
>WIRE 592 128 592 16
>WIRE 592 128 544 128
>WIRE 624 128 592 128
>WIRE 640 128 624 128
>WIRE 656 128 640 128
>WIRE 752 128 736 128
>WIRE 864 128 752 128
>WIRE 368 144 368 128
>WIRE 640 160 640 128
>WIRE 864 160 864 128
>WIRE 752 176 752 128
>WIRE 176 208 176 144
>WIRE 224 208 176 208
>WIRE 256 208 224 208
>WIRE 176 224 176 208
>WIRE 432 272 432 16
>WIRE 480 272 432 272
>WIRE 592 272 544 272
>WIRE 640 272 640 240
>WIRE 640 272 592 272
>WIRE 720 272 640 272
>WIRE 752 272 752 240
>WIRE 752 272 720 272
>WIRE 864 272 864 240
>WIRE 864 272 752 272
>WIRE -16 304 -16 192
>WIRE 176 304 176 288
>WIRE 176 304 -16 304
>WIRE 368 304 368 208
>WIRE 368 304 176 304
>WIRE -16 320 -16 304
>WIRE 464 352 464 128
>WIRE 480 352 464 352
>WIRE 592 352 592 272
>WIRE 592 352 544 352
>FLAG -16 320 0
>FLAG 368 16 A
>FLAG 224 208 VC1
>FLAG 752 128 C
>FLAG 720 272 D
>FLAG 368 128 B
>FLAG 624 128 E
>SYMBOL misc\\DIAC 320 176 R90
>WINDOW 0 0 32 VBottom 2
>WINDOW 3 64 32 VTop 2
>WINDOW 123 92 32 VTop 2
>SYMATTR InstName Q1
>SYMATTR Value2 VK=30
>SYMBOL voltage -16 96 R0
>WINDOW 0 10 -1 Left 2
>WINDOW 3 -65 137 Left 2
>WINDOW 123 0 0 Left 2
>WINDOW 39 0 0 Left 2
>SYMATTR InstName V1
>SYMATTR Value SINE(0 166 60 0 0 0 20)
>SYMBOL res 160 160 M180
>WINDOW 0 36 76 Left 2
>WINDOW 3 36 40 Left 2
>SYMATTR InstName R1
>SYMATTR Value 200k
>SYMBOL cap 160 224 R0
>SYMATTR InstName C1
>SYMATTR Value .062u
>SYMBOL misc\\TRIAC 336 144 R0
>SYMATTR InstName U1
>SYMBOL diode 544 0 R90
>WINDOW 0 0 32 VBottom 2
>WINDOW 3 32 32 VTop 2
>SYMATTR InstName D1
>SYMATTR Value 1N4007
>SYMBOL diode 544 112 R90
>WINDOW 0 0 32 VBottom 2
>WINDOW 3 32 32 VTop 2
>SYMATTR InstName D2
>SYMATTR Value 1N4007
>SYMBOL diode 480 288 R270
>WINDOW 0 32 32 VTop 2
>WINDOW 3 0 32 VBottom 2
>SYMATTR InstName D3
>SYMATTR Value 1N4007
>SYMBOL diode 480 368 R270
>WINDOW 0 32 32 VTop 2
>WINDOW 3 0 32 VBottom 2
>SYMATTR InstName D4
>SYMATTR Value 1N4007
>SYMBOL res 624 144 R0
>SYMATTR InstName R2
>SYMATTR Value 230
>SYMBOL cap 736 176 R0
>SYMATTR InstName C2
>SYMATTR Value 1640uf
>SYMBOL res 752 112 R90
>WINDOW 0 0 56 VBottom 2
>WINDOW 3 32 56 VTop 2
>SYMATTR InstName R3
>SYMATTR Value 0.1
>SYMBOL res 352 16 R0
>SYMATTR InstName R4
>SYMATTR Value 1k
>SYMBOL res 320 0 R90
>WINDOW 0 0 56 VBottom 2
>WINDOW 3 32 56 VTop 2
>SYMATTR InstName R5
>SYMATTR Value 10
>SYMBOL res 848 144 R0
>SYMATTR InstName R6
>SYMATTR Value 100k
>TEXT 40 -48 Left 2 !.tran 0 500ms 0 10u
>TEXT -376 280 Left 2 !.subckt DIAC T1 T2\n* default parameters\n.param RS=
>10 ; series resistance\n.param VK=20 ; breakdown voltage\nQ1 N002 N001 T2 0 
>PN\nQ2 N001 N002 N005 0 NP\nR1 N002 N004 {20K*(VK-1)}\nR2 N004 T2 9.5K\nR3 
>N002 N005 9.5K\nQ3 N004 N003 N005 0 PN\nQ4 N003 N004 T2 0 NP\nR4 T1 N005 
>{RS}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP Cjc=10p Cje=10p\n.ends 
>DIAC
>TEXT -376 16 Left 2 !.subckt TRIAC MT2 G MT1\n.param R=10K\nQ1 N001 G MT1 0 
>NP\nQ2 N001 N002 MT2 0 NP\nQ3 N002 N001 MT1 0 PN\nQ4 G N001 MT2 0 PN\nR1 
>MT2 N002 {R}\nR2 G MT1 {R}\n.model PN NPN Cjc=10p Cje=10p\n.model NP PNP 
>Cjc=10p Cje=10p\n.ends TRIAC
>TEXT 40 -80 Left 2 ;'DIAC TRIAC Light Dimmer Step RDim
>TEXT 64 336 Left 2 ;200e3*.062e-6 = 0.0124 seconds
>TEXT -56 432 Left 2 !.model 1N4007 D(Is=14.11n N=1.984 Rs=33.89m Ikf=94.81 
>Xti=3 Eg=1.11 Cjo=25.89p \n+M=.44 Vj=.3245 Fc=.5 Bv=1500 Ibv=10u Tt=5.7u 
>Iave=1A Vpk=1500 mfg=Motorola type=silicon)
>TEXT 632 312 Left 2 ;100e3*1540e-6= 154 seconds
>
>The PLT file
>
>[Transient Analysis]
>{
>   Npanes: 2
>   Active Pane: 1
>   {
>      traces: 3 {524293,0,"V(d,c)"} {524294,0,"V(d,e)"} {34603012,1,"I
>(R3)"}
>      X: ('m',0,0,0.05,0.5)
>      Y[0]: (' ',0,0,10,130)
>      Y[1]: (' ',0,-4,2,22)
>      Volts: (' ',0,0,0,0,10,130)
>      Amps: (' ',0,0,0,-4,2,22)
>      Log: 0 0 0
>      GridStyle: 1
>   },
>   {
>      traces: 2 {524291,0,"V(b)"} {524290,0,"V(a)"}
>      X: ('m',0,0,0.05,0.5)
>      Y[0]: (' ',0,-180,30,180)
>      Y[1]: (' ',0,1e+308,3,-1e+308)
>      Volts: (' ',0,0,0,-180,30,180)
>      Log: 0 0 0
>      GridStyle: 1
>   }
>}
Reply by legg ●September 8, 20232023-09-08
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
<spamme@not.com> wrote:


>I recently changed the overhead fluorescent lamps for LED replacements. 
>
>Very soon, I noticed they were flickering a lot more the the old 
>fluorescents. 
>

<snip>

>The lED lamps contain their own bridge rectifier to convert the AC line 
>voltage to DC to drive the lamps.
>

<snip>

Mike, there are many fluorescent replacement types of LED lamp.
At this low (and usually fixed) power level, it's possible to 
skin this cat any number of ways.

If you use a variac to evaluate brightness vs line voltage on 
the lamps you are using, you'll see the range of voltages 
required to perform the dimming function.

I think you'll be surprised at just how low these voltage 
values can be and how narrow the adjustment range is. 
Only types that are designed for dimming, or dimmers 
designed for LEDs can give you satisfactory performance.

R4 . . . . this is one cat that isn't skinned properly.

RL
Reply by Mike Monett VE3BTI ●September 8, 20232023-09-08
legg <legg@nospam.magma.ca> wrote:


> <snip>
>>The lED lamps contain their own bridge rectifier to convert the AC line 
>>voltage to DC to drive the lamps.
>>
> <snip>
> 
> Mike, there are many fluorescent replacement types of LED lamp.
> At this low (and usually fixed) power level, it's possible to 
> skin this cat any number of ways.
> 
> If you use a variac to evaluate brightness vs line voltage on 
> the lamps you are using, you'll see the range of voltages 
> required to perform the dimming function.
> 
> I think you'll be surprised at just how low these voltage 
> values can be and how narrow the adjustment range is. 
> Only types that are designed for dimming, or dimmers 
> designed for LEDs can give you satisfactory performance.
> 
> R4 . . . . this is one cat that isn't skinned properly.
> 
> RL


Thanks for your message.

I am interested in eliminating flicker due to line transients. A capacitor 
stores energy and supplies it to the LED during a transient. 

Ordinary dimmers are not intended to drive capacitors. This will be the 
first time. I will have to see how they perform but I am pretty confident 
they will work in this application.
 
I am not interested in actually dimming the light. I have a 0 - 300v supply 
that I can use to see how the LED lamps perform with DC. I understand they 
operate over a narrow range, much like a diode, as they are basically 
current driven.

I agree with you. R4 may not be needed. I included it as I didn't know how 
it would affect the operation of the circuit. Changing it to 1e6 ohms made 
no difference.



-- 
MRM
Reply by Lasse Langwadt Christensen ●September 8, 20232023-09-08
fredag den 8. september 2023 kl. 20.49.57 UTC+2 skrev Mike Monett VE3BTI:

> legg <le...@nospam.magma.ca> wrote: 
> 
> > <snip> 
> >>The lED lamps contain their own bridge rectifier to convert the AC line 
> >>voltage to DC to drive the lamps. 
> >> 
> > <snip> 
> > 
> > Mike, there are many fluorescent replacement types of LED lamp. 
> > At this low (and usually fixed) power level, it's possible to 
> > skin this cat any number of ways. 
> > 
> > If you use a variac to evaluate brightness vs line voltage on 
> > the lamps you are using, you'll see the range of voltages 
> > required to perform the dimming function. 
> > 
> > I think you'll be surprised at just how low these voltage 
> > values can be and how narrow the adjustment range is. 
> > Only types that are designed for dimming, or dimmers 
> > designed for LEDs can give you satisfactory performance. 
> > 
> > R4 . . . . this is one cat that isn't skinned properly. 
> > 
> > RL
> Thanks for your message. 
> 
> I am interested in eliminating flicker due to line transients. A capacitor 
> stores energy and supplies it to the LED during a transient. 
> 
> Ordinary dimmers are not intended to drive capacitors. This will be the 
> first time. I will have to see how they perform but I am pretty confident 
> they will work in this application. 
> 
> I am not interested in actually dimming the light. I have a 0 - 300v supply 
> that I can use to see how the LED lamps perform with DC. I understand they 
> operate over a narrow range, much like a diode, as they are basically 
> current driven. 
> 
> I agree with you. R4 may not be needed. I included it as I didn't know how 
> it would affect the operation of the circuit. Changing it to 1e6 ohms made 
> no difference. 
> 


most LED lamps have a build in constant current driver so they will be the same 
brightness at any voltage high enough for the LEDs and regulation

or that they have a capacitive dropper that will only work on DC and have a terrible power factor
Reply by Mike Monett VE3BTI ●September 8, 20232023-09-08
piglet <erichpwagner@hotmail.com> wrote:


> 
> The model you used for 1N4007 has something very wrong - if I replace 
> with one of the 600V types included with LTSpice then the crazy currents 
> disappear and the circuit does more as you describe. Have you checked 
> Pdiss in R4?
> 
> piglet

 
VII doesn't have the 1N4007, so I got the model from LTspice IV. It shows a 
PIV of 1,500 v. There are no 600 V versions in IV.

I see no crazy currents in IV or VII. Can you tell me more about what you are 
seeing?

I tried to plot the power in R4 but had no luck in IV or VII. I tried to 
calculate pwr(V(x), V(a)) but got 9.65e+307 with no units. So I have to 
guess. I'll try a 2W wirewound.



-- 
MRM