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a schematic - Tpower.gif
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a schematic - Tpower.gif
John Larkin a écrit :
What do you do with your 24V? Referencing C68 and C73 to GND will couple less 12V noise to the 24V output. OK there's the filter and zener, but it's easy and you're not doing kVs. -- Thanks, Fred. |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin
wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson
wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 19:10:36 +0200, Fred Bartoli
r_AndThisToo wrote: John Larkin a écrit : What do you do with your 24V? It powers some little logic-level shifters, which I posted about a couple of weeks ago. They take a 3.3 volt FPGA output and shift it up about 0.8 volts to drive some 5-volt CMOS logic. Without the shift, the cmos gadgets have asymmetric prop delays and high static power dissipation. Current required is only about 50 uA per shifter. Referencing C68 and C73 to GND will couple less 12V noise to the 24V output. OK there's the filter and zener, but it's easy and you're not doing kVs. But we get a free extra 12 volts out of the C-W this way, which we need for decent zener regulation. If we grounded the low side, we'd need another multiplier section. Some switchers will freak without that R99 thing. John |
a schematic - Tpower.gif
Jim Thompson wrote:
On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) And 120V for the margarita mixer... -- SCNR, Joerg http://www.analogconsultants.com |
a schematic - Tpower.gif
John Larkin a écrit :
On Fri, 30 Mar 2007 19:10:36 +0200, Fred Bartoli r_AndThisToo wrote: John Larkin a écrit : What do you do with your 24V? It powers some little logic-level shifters, which I posted about a couple of weeks ago. They take a 3.3 volt FPGA output and shift it up about 0.8 volts to drive some 5-volt CMOS logic. Without the shift, the cmos gadgets have asymmetric prop delays and high static power dissipation. Current required is only about 50 uA per shifter. Ahmm, remember. So the bit of extra noise probably matters not. Referencing C68 and C73 to GND will couple less 12V noise to the 24V output. OK there's the filter and zener, but it's easy and you're not doing kVs. But we get a free extra 12 volts out of the C-W this way, which we need for decent zener regulation. If we grounded the low side, we'd need another multiplier section. Nope. You don't ground the diodes, just the capacitors. Then you obtain the same output voltage. C68 and C73 are not flying. Some switchers will freak without that R99 thing. Sure. Those with CM feedback and those with switch current limit. -- Thanks, Fred. |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin
wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 13:28:51 -0700, Jim Thompson
wrote: On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf ...Jim Thompson Terrifying. I may not be able to sleep tonight. John |
a schematic - Tpower.gif
On Fri, 30 Mar 2007 18:57:37 -0800, John Larkin
wrote: On Fri, 30 Mar 2007 13:28:51 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf ...Jim Thompson Terrifying. I may not be able to sleep tonight. John Sno-o-o-o-ort! Took youngest granddaughter to her birthday dinner at "My Big Fat Greek Restaurant". The belly dancers were teaching her their routines and gave her a set of castanets. N and I did two bottles of Nousa Boutari... we'll sleep well tonight ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
Jim Thompson wrote:
On Fri, 30 Mar 2007 18:57:37 -0800, John Larkin wrote: On Fri, 30 Mar 2007 13:28:51 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf ...Jim Thompson Terrifying. I may not be able to sleep tonight. John Sno-o-o-o-ort! Took youngest granddaughter to her birthday dinner at "My Big Fat Greek Restaurant". The belly dancers were teaching her their routines and gave her a set of castanets. Did you ever see the movie "My Big Fat Greek Wedding"? Absolutely worth it. N and I did two bottles of Nousa Boutari... we'll sleep well tonight ;-) ...Jim Thompson -- Regards, Joerg http://www.analogconsultants.com |
a schematic - Tpower.gif
"Jim Thompson" wrote
in message On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf Could you show the waveforms for L1 and D1 current? -- Reply in group, but if emailing add another zero, and remove the last word. |
a schematic - Tpower.gif
On Sat, 31 Mar 2007 19:39:03 GMT, Joerg
wrote: Jim Thompson wrote: [snip] Took youngest granddaughter to her birthday dinner at "My Big Fat Greek Restaurant". The belly dancers were teaching her their routines and gave her a set of castanets. Did you ever see the movie "My Big Fat Greek Wedding"? Absolutely worth it. [snip] Of course. You should know me... I have a copy on DVD ;-) (It's actually about the same cost to buy a DVD of a movie as it is for two people to go see it in the theater. And you don't have to put up with the pair of old biddies behind you that want to talk all thru the movie :-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
On Sat, 31 Mar 2007 19:58:10 GMT, "Tom Del Rosso"
wrote: "Jim Thompson" wrote in message On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf Could you show the waveforms for L1 and D1 current? I'll see if I can do that. This was actually built before CAD, and is in several GenRad portable products... so the controller in the drawing is actually "fudge" for demo purposes ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
Jim Thompson wrote:
On Sat, 31 Mar 2007 19:39:03 GMT, Joerg wrote: Jim Thompson wrote: [snip] Took youngest granddaughter to her birthday dinner at "My Big Fat Greek Restaurant". The belly dancers were teaching her their routines and gave her a set of castanets. Did you ever see the movie "My Big Fat Greek Wedding"? Absolutely worth it. [snip] Of course. You should know me... I have a copy on DVD ;-) We have it on, gasp, VCR tape :-) Our neighbors (she Greek Orthodox, he came into the family as a "xeno") said their wedding was very similar. Yep, including the baptism. (It's actually about the same cost to buy a DVD of a movie as it is for two people to go see it in the theater. And you don't have to put up with the pair of old biddies behind you that want to talk all thru the movie :-) We went once here. Digital screen. Too pixely :-( -- Regards, Joerg http://www.analogconsultants.com |
a schematic - Tpower.gif
On Sat, 31 Mar 2007 19:58:10 GMT, "Tom Del Rosso"
wrote: "Jim Thompson" wrote in message On Fri, 30 Mar 2007 11:20:49 -0700, John Larkin wrote: On Fri, 30 Mar 2007 10:29:01 -0700, Jim Thompson wrote: On Fri, 30 Mar 2007 09:42:01 -0700, John Larkin wrote: OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf Could you show the waveforms for L1 and D1 current? Now updated on my website. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
a schematic - Tpower.gif
"Jim Thompson" wrote
in message On Sat, 31 Mar 2007 19:58:10 GMT, "Tom Del Rosso" wrote: "Jim Thompson" wrote in message http://analog-innovations.com/SED/Ol...tiveOutput.pdf Could you show the waveforms for L1 and D1 current? Now updated on my website. Thanks. -- Reply in group, but if emailing add another zero, and remove the last word. |
a schematic - Tpower.gif
"Jim Thompson" wrote in message ... OK. How about -5V out of there at the same time ?:-) ...Jim Thompson We designed this board specifically to need no negative supplies, but I have done this same trick to go negative. You can also turn the inductor into a transformer, or center-tap it, as needed. John You don't need a transformer... http://analog-innovations.com/SED/Ol...tiveOutput.pdf Could you show the waveforms for L1 and D1 current? Now updated on my website. ...Jim Thompson We had a buck step-down from 24V to 7V. I took a charge pump off the connection between the switch and the inductor. Put a bead in series with the charge pump capacitor so it does not cause a current spike in the switch. Gave a decent negative bias supply. Oppie |
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