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Bridge rectifier question

Started by Daku November 14, 2011
Maybe this a very stupid question. I have a SPICE model of a diode
bridge. When one of the nodes is grounded, correct rectification
occurs with a sine input. The sine input is with reference to ground.
Otherwise, if the sine input is floating, and correspondingly the
diode bridge's node that was previously grounded is connected to the
second node of the sine input, I get error messages. I am running with
TRAN option. Any hints, suggestions would be of immense help.
On Mon, 14 Nov 2011 07:34:51 -0800 (PST), Daku <dakupoto@gmail.com>
wrote:

>Maybe this a very stupid question. I have a SPICE model of a diode >bridge. When one of the nodes is grounded, correct rectification >occurs with a sine input. The sine input is with reference to ground. >Otherwise, if the sine input is floating, and correspondingly the >diode bridge's node that was previously grounded is connected to the >second node of the sine input, I get error messages. I am running with >TRAN option. Any hints, suggestions would be of immense help.
Post the circuit and the model. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
"Daku" <dakupoto@gmail.com> wrote in message 
news:0f2ecdaa-0d03-4b08-aa0d-7a3d3d73d64a@u24g2000pru.googlegroups.com...
> Maybe this a very stupid question. I have a SPICE model of a diode > bridge. When one of the nodes is grounded, correct rectification > occurs with a sine input. The sine input is with reference to ground. > Otherwise, if the sine input is floating, and correspondingly the > diode bridge's node that was previously grounded is connected to the > second node of the sine input, I get error messages. I am running with > TRAN option. Any hints, suggestions would be of immense help. >
I found your description a little tricky to follow, but you can put it in a nutshell by stating you can only ground one terminal of the bridge otherwise one or more of the diodes will shunt alternate half cycles. HTH.
On Mon, 14 Nov 2011 17:43:47 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

> >"Daku" <dakupoto@gmail.com> wrote in message >news:0f2ecdaa-0d03-4b08-aa0d-7a3d3d73d64a@u24g2000pru.googlegroups.com... >> Maybe this a very stupid question. I have a SPICE model of a diode >> bridge. When one of the nodes is grounded, correct rectification >> occurs with a sine input. The sine input is with reference to ground. >> Otherwise, if the sine input is floating, and correspondingly the >> diode bridge's node that was previously grounded is connected to the >> second node of the sine input, I get error messages. I am running with >> TRAN option. Any hints, suggestions would be of immense help. >> > >I found your description a little tricky to follow, but you can put it in a >nutshell by stating you can only ground one terminal of the bridge otherwise >one or more of the diodes will shunt alternate half cycles. > >HTH. >
Sounds like you need a ground somewhere in your design. Every node needs a DC path to ground. If you try to just have everything floating, then the simulation won't work... Charlie
On Mon, 14 Nov 2011 07:34:51 -0800 (PST), Daku <dakupoto@gmail.com>
wrote:

>Maybe this a very stupid question. I have a SPICE model of a diode >bridge. When one of the nodes is grounded, correct rectification >occurs with a sine input. The sine input is with reference to ground. >Otherwise, if the sine input is floating, and correspondingly the >diode bridge's node that was previously grounded is connected to the >second node of the sine input, I get error messages. I am running with >TRAN option. Any hints, suggestions would be of immense help.
Use a very large-valued resistance to un-float the nodes for SPICE. Version 4 SHEET 1 880 680 WIRE -1056 -32 -1072 -32 WIRE -960 -32 -976 -32 WIRE -752 -32 -816 -32 WIRE -656 -32 -752 -32 WIRE -336 -32 -352 -32 WIRE -240 -32 -256 -32 WIRE -32 -32 -96 -32 WIRE 64 -32 -32 -32 WIRE 464 -32 336 -32 WIRE 560 -32 464 -32 WIRE -752 16 -752 -32 WIRE -656 16 -656 -32 WIRE -32 16 -32 -32 WIRE 64 16 64 -32 WIRE 464 16 464 -32 WIRE 560 16 560 -32 WIRE -1072 128 -1072 -32 WIRE -960 128 -960 -32 WIRE -816 128 -816 -32 WIRE -656 128 -656 80 WIRE -528 128 -656 128 WIRE -352 128 -352 -32 WIRE -240 128 -240 -32 WIRE -96 128 -96 -32 WIRE 64 128 64 80 WIRE 192 128 64 128 WIRE 336 128 336 -32 WIRE 560 128 560 80 WIRE 688 128 560 128 WIRE -752 176 -752 80 WIRE -576 176 -752 176 WIRE -32 176 -32 80 WIRE 144 176 -32 176 WIRE 464 176 464 80 WIRE 640 176 464 176 WIRE -752 208 -752 176 WIRE -656 208 -656 128 WIRE -576 208 -576 176 WIRE -32 208 -32 176 WIRE 64 208 64 128 WIRE 144 208 144 176 WIRE 464 208 464 176 WIRE 560 208 560 128 WIRE 640 208 640 176 WIRE -1072 352 -1072 208 WIRE -960 352 -960 208 WIRE -960 352 -1072 352 WIRE -928 352 -960 352 WIRE -816 352 -816 208 WIRE -816 352 -848 352 WIRE -752 352 -752 272 WIRE -752 352 -816 352 WIRE -656 352 -656 272 WIRE -656 352 -752 352 WIRE -352 352 -352 208 WIRE -240 352 -240 208 WIRE -240 352 -352 352 WIRE -208 352 -240 352 WIRE -96 352 -96 208 WIRE -96 352 -128 352 WIRE -32 352 -32 272 WIRE -32 352 -96 352 WIRE 64 352 64 272 WIRE 64 352 -32 352 WIRE 336 352 336 208 WIRE 464 352 464 272 WIRE 464 352 336 352 WIRE 560 352 560 272 WIRE 560 352 464 352 WIRE -1072 416 -1072 352 WIRE 336 416 336 352 WIRE -1072 544 -1072 496 WIRE 336 544 336 496 FLAG 640 208 0 FLAG 144 208 0 FLAG 336 544 0 FLAG -576 208 0 FLAG -1072 544 0 SYMBOL voltage 336 112 R0 WINDOW 0 -81 36 Left 2 WINDOW 3 -77 71 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(0 10 60) SYMBOL diode 448 208 R0 WINDOW 0 -38 28 Left 2 WINDOW 3 -18 63 Left 2 SYMATTR InstName D1 SYMBOL diode 544 16 R0 WINDOW 0 40 29 Left 2 WINDOW 3 24 63 Left 2 SYMATTR InstName D2 SYMBOL diode 480 80 R180 WINDOW 0 41 33 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D3 SYMBOL diode 576 272 R180 WINDOW 0 -37 36 Left 2 WINDOW 3 -17 0 Left 2 SYMATTR InstName D4 SYMBOL ind2 -80 112 M0 SYMATTR InstName L2 SYMATTR Value 1 SYMATTR Type ind SYMBOL ind2 -256 112 R0 SYMATTR InstName L1 SYMATTR Value 1 SYMATTR Type ind SYMBOL voltage -352 112 R0 WINDOW 0 -81 36 Left 2 WINDOW 3 -77 71 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value SINE(0 10 60) SYMBOL diode -48 208 R0 WINDOW 0 -38 28 Left 2 WINDOW 3 -18 63 Left 2 SYMATTR InstName D5 SYMBOL diode 48 16 R0 WINDOW 0 40 29 Left 2 WINDOW 3 24 63 Left 2 SYMATTR InstName D6 SYMBOL diode -16 80 R180 WINDOW 0 41 33 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D7 SYMBOL diode 80 272 R180 WINDOW 0 -37 36 Left 2 WINDOW 3 -17 0 Left 2 SYMATTR InstName D8 SYMBOL res -240 -48 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value .1 SYMBOL res 320 400 R0 SYMATTR InstName R1 SYMATTR Value 1G SYMBOL res -112 336 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 1G SYMBOL ind2 -800 112 M0 SYMATTR InstName L3 SYMATTR Value 1 SYMATTR Type ind SYMBOL ind2 -976 112 R0 SYMATTR InstName L4 SYMATTR Value 1 SYMATTR Type ind SYMBOL voltage -1072 112 R0 WINDOW 0 -81 36 Left 2 WINDOW 3 -77 71 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value SINE(0 10 60) SYMBOL diode -768 208 R0 WINDOW 0 -38 28 Left 2 WINDOW 3 -18 63 Left 2 SYMATTR InstName D9 SYMBOL diode -672 16 R0 WINDOW 0 40 29 Left 2 WINDOW 3 24 63 Left 2 SYMATTR InstName D10 SYMBOL diode -736 80 R180 WINDOW 0 41 33 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D11 SYMBOL diode -640 272 R180 WINDOW 0 -37 36 Left 2 WINDOW 3 -17 0 Left 2 SYMATTR InstName D12 SYMBOL res -960 -48 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value .1 SYMBOL res -832 336 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 1G SYMBOL res -1088 400 R0 SYMATTR InstName R6 SYMATTR Value 1G TEXT -216 -48 Left 2 !K L1 L2 1 TEXT -210 -76 Left 2 !.tran .05 TEXT -936 -48 Left 2 !K L1 L2 1 TEXT -930 -76 Left 2 !.tran .05 -- JF
"Charlie E." <edmondson@ieee.org> wrote in message 
news:leq2c7tvl2mhamsop1oo409cbog3qmt1eq@4ax.com...
> On Mon, 14 Nov 2011 17:43:47 -0000, "Ian Field" > <gangprobing.alien@ntlworld.com> wrote: > >> >>"Daku" <dakupoto@gmail.com> wrote in message >>news:0f2ecdaa-0d03-4b08-aa0d-7a3d3d73d64a@u24g2000pru.googlegroups.com... >>> Maybe this a very stupid question. I have a SPICE model of a diode >>> bridge. When one of the nodes is grounded, correct rectification >>> occurs with a sine input. The sine input is with reference to ground. >>> Otherwise, if the sine input is floating, and correspondingly the >>> diode bridge's node that was previously grounded is connected to the >>> second node of the sine input, I get error messages. I am running with >>> TRAN option. Any hints, suggestions would be of immense help. >>> >> >>I found your description a little tricky to follow, but you can put it in >>a >>nutshell by stating you can only ground one terminal of the bridge >>otherwise >>one or more of the diodes will shunt alternate half cycles. >> >>HTH. >> > Sounds like you need a ground somewhere in your design. Every node > needs a DC path to ground. If you try to just have everything > floating, then the simulation won't work...
Who said it had to be floating - I didn't.
.OPTION RSHUNT 1E8

Tim

-- 
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Daku" <dakupoto@gmail.com> wrote in message 
news:0f2ecdaa-0d03-4b08-aa0d-7a3d3d73d64a@u24g2000pru.googlegroups.com...
> Maybe this a very stupid question. I have a SPICE model of a diode > bridge. When one of the nodes is grounded, correct rectification > occurs with a sine input. The sine input is with reference to ground. > Otherwise, if the sine input is floating, and correspondingly the > diode bridge's node that was previously grounded is connected to the > second node of the sine input, I get error messages. I am running with > TRAN option. Any hints, suggestions would be of immense help.
Daku wrote:

> Maybe this a very stupid question. I have a SPICE model of a diode > bridge. When one of the nodes is grounded, correct rectification > occurs with a sine input. The sine input is with reference to ground. > Otherwise, if the sine input is floating, and correspondingly the > diode bridge's node that was previously grounded is connected to the > second node of the sine input, I get error messages. I am running with > TRAN option. Any hints, suggestions would be of immense help.
Yes, we see your dilemma... :) The SINE signal is using a common ground and thus the bridge isn't going work as you wish.. What you're after is to simulate a secondary of a CT transformer. Use 2 SINE wave generators, place them in series with the CT as your common. Then use the lower (-) output as one feed and the upper (+) output as your other feed to the AC inputs of the bridge. The SINE gen will have its Common and the bridge will have the 2 sources it needs. Jamie
On Nov 14, 8:16=A0pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
> Daku wrote: > > Maybe this a very stupid question. I have a SPICE model of a diode > > bridge. When one of the nodes is grounded, correct rectification > > occurs with a sine input. The sine input is with reference to ground. > > Otherwise, if the sine input is floating, and correspondingly the > > diode bridge's node that was previously grounded is connected to the > > second node of the sine input, I get error messages. I am running with > > TRAN option. Any hints, suggestions would be of immense help. > > =A0 Yes, we see your dilemma... :) > > =A0 The SINE signal is using a common ground and thus the bridge > isn't going work as you wish.. > > =A0 =A0What you're after is to simulate a secondary of a CT transformer. > > =A0 Use 2 SINE wave generators, place them in series with the CT as your > common. Then use the lower (-) output as one feed and the upper (+) > output as your other feed to the AC inputs of the bridge. > > =A0 =A0The SINE gen will have its Common and the bridge will have the 2 > sources it needs. > > =A0 Jamie
I have already tried your suggestion, but the problem now is that the bridge output is in the range of 10e-15. The following is my simple SPICE file: Test Brg_rect .MODEL DI_1N5711W D(IS=3D315E-9 RS=3D2.80 BV=3D70.0 IBV=3D0.00085253 CJO=3D= 2.00p M=3D0.333 N=3D2.03 TT=3D1.44n ) VS0 1 0 DC 0.0 SIN(0, 5.0, 60.0, 0, 0, 0) VS1 2 0 DC 0.0 SIN(0, 5.0, 60.0, 0, 0, 0) C0 3 4 50.0uF D0 3 1 DI_1N5711W D1 1 4 DI_1N5711W D2 3 2 DI_1N5711W D3 2 4 DI_1N5711W .OPTIONS NOPAGE .IC V(3)=3D0.0 V(4)=3D0.0 .PROBE .TRAN 10MS 200MS 1MS UIC .PRINT TRAN V(1) V(2) V(3,4) .END
On Mon, 14 Nov 2011 21:06:16 -0800 (PST), Daku <dakupoto@gmail.com>
wrote:

>On Nov 14, 8:16&#2013266080;pm, Jamie ><jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote: >> Daku wrote: >> > Maybe this a very stupid question. I have a SPICE model of a diode >> > bridge. When one of the nodes is grounded, correct rectification >> > occurs with a sine input. The sine input is with reference to ground. >> > Otherwise, if the sine input is floating, and correspondingly the >> > diode bridge's node that was previously grounded is connected to the >> > second node of the sine input, I get error messages. I am running with >> > TRAN option. Any hints, suggestions would be of immense help. >> >> &#2013266080; Yes, we see your dilemma... :) >> >> &#2013266080; The SINE signal is using a common ground and thus the bridge >> isn't going work as you wish.. >> >> &#2013266080; &#2013266080;What you're after is to simulate a secondary of a CT transformer. >> >> &#2013266080; Use 2 SINE wave generators, place them in series with the CT as your >> common. Then use the lower (-) output as one feed and the upper (+) >> output as your other feed to the AC inputs of the bridge. >> >> &#2013266080; &#2013266080;The SINE gen will have its Common and the bridge will have the 2 >> sources it needs. >> >> &#2013266080; Jamie > >I have already tried your suggestion, but the problem now is that the >bridge output is in the range of 10e-15. The following is my simple >SPICE >file: >Test Brg_rect >.MODEL DI_1N5711W D(IS=315E-9 RS=2.80 BV=70.0 IBV=0.00085253 CJO=2.00p >M=0.333 N=2.03 TT=1.44n ) > > > >VS0 1 0 DC 0.0 SIN(0, 5.0, 60.0, 0, 0, 0) >VS1 2 0 DC 0.0 SIN(0, 5.0, 60.0, 0, 0, 0)
Aren't nodes 1 and 2 in phase? If so, V3:4 will be zero. John
> >C0 3 4 50.0uF >D0 3 1 DI_1N5711W >D1 1 4 DI_1N5711W >D2 3 2 DI_1N5711W >D3 2 4 DI_1N5711W > > >.OPTIONS NOPAGE >.IC V(3)=0.0 V(4)=0.0 >.PROBE >.TRAN 10MS 200MS 1MS UIC >.PRINT TRAN V(1) V(2) V(3,4) >.END