Turns ratio change

Started by me in sci.electronics.design10 years ago 3 replies

HV power supply...160kV/15mA 400vdc pfc rail; Multiplier, 10 stage: I've changed my primary turns from 19 T to 15 T and changed...

HV power supply...160kV/15mA 400vdc pfc rail; Multiplier, 10 stage: I've changed my primary turns from 19 T to 15 T and changed secondary turns so ratio stays the same, yet I am unable to acheive same output voltage- It's a 10 stage cockroft-walton multiplier. I would have thought that I would not need to change tuning, just to expect larger Ipri. HV switcher f=25kHz. I'm only able to g...


Help: Electrical Switcher Project

Started by Searcher7 in sci.electronics.design10 years ago 6 replies

Has anyone ever created an electrical switcher that *mechanically* allows one to switch between appliances that run on standard...

Has anyone ever created an electrical switcher that *mechanically* allows one to switch between appliances that run on standard household current?(ie: TVs, stereo, computer, ect). If not, can I get ideas on what it would take to build something like it? Thanks a lot. Darren Harris Staten Island, New York.


Notches in ground planes for multi-power multi-channel board

Started by Anonymous in sci.electronics.design10 years ago 72 replies

All, I am designing a multi-channel board and I have individual linear regulators for each channel running off a common switcher. Now, my...

All, I am designing a multi-channel board and I have individual linear regulators for each channel running off a common switcher. Now, my concern is that due to the split power planes, which are like thin fingers running through the board, I will cause potential differences based on the current in different channels, especially, because I have a common ground plane. Now, I was thinking m...


SMPS oddities

Started by Bitman in sci.electronics.design10 years ago 14 replies

Hi all, I've been studying SMPSs for a while out of personal interest, and I stumbled upon an old schematic for a discrete component-based...

Hi all, I've been studying SMPSs for a while out of personal interest, and I stumbled upon an old schematic for a discrete component-based SMPS: http://bitman3.altervista.org/SMPS.png As I understand it, this is a self-oscillating SMPS operating in current mode. T302 is the main switcher, Th301 is the turn-off SCR, T301 acts as the voltage error amplifier whose output controls the m...


synchronizing SMPS for ADC sampling noise reduction

Started by Jamie Morken in sci.electronics.design9 years ago 9 replies

Hi, I am working on a switcher with ADC sampling at the same frequency as the main switcher PWM frequency, they are already synchronized to...

Hi, I am working on a switcher with ADC sampling at the same frequency as the main switcher PWM frequency, they are already synchronized to reduce noise when sampling the ADC. There are also several small flybacks (10watts at 12Volts output) on the board, I am thinking of syncing their PWM as well, but I am wondering if syncing a flyback is the same as syncing a forward converter for ti...


7805 replacement thingie

Started by John Larkin in sci.electronics.design9 years ago 11 replies

There seem to be several swicthmode regulators that are packaged to drop into a TO-220 7805-type regulator place. I have a board that has +12,...

There seem to be several swicthmode regulators that are packaged to drop into a TO-220 7805-type regulator place. I have a board that has +12, and I need +5 and 3.3, maybe 500 mA each, and there's no room to place switcher parts, so I have to go vertical. This seems like an easy way to do it. I could use two, or maybe I could just use one of these to get to +5, then use a tiny MHz switcher...


POWER SUPPLY FIRE

Started by Anonymous in sci.electronics.design9 years ago 39 replies

Ok, I am helping a friend at a small company investigate a fire. He makes a 0-30 kV switching HV supply in a nice AL box. Uses 110V into a 15V...

Ok, I am helping a friend at a small company investigate a fire. He makes a 0-30 kV switching HV supply in a nice AL box. Uses 110V into a 15V switcher that drives his switcher that drives a coil and multiplier for 30 Kv at about 1mA. He just got a letter from a client, accusing his unit of starting the fire, and while I can't go into too many details, the question is: Has anybody e...


Switcher Inductor Ripple Current

Started by Anonymous in sci.electronics.design9 years ago 6 replies

I need to design a constant current buck switcher. I need to power a Perkin Elmer krypton long arc lamp, a QCW12. At the middle of the lamp's...

I need to design a constant current buck switcher. I need to power a Perkin Elmer krypton long arc lamp, a QCW12. At the middle of the lamp's V-I curve, near where I want to run, the lamp voltage is 155V DC @ 20A. I want to run at 80-100 Khz off rectified 220 line. I've serviced these systems since 1988, so I have a idea what needs to be done to support the lamp, but I never rippe...


LTC switcher, PADS

Started by John Larkin in sci.electronics.design8 years ago 25 replies

OK, we are getting tired of messing around with switcher chips, inductors, schottkies, cap ESRs, all that. So we're going to start using these...

OK, we are getting tired of messing around with switcher chips, inductors, schottkies, cap ESRs, all that. So we're going to start using these gadgets http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1010,C1778,C1764,P39569 which seem to be very cool dudes. We're running the eval board and it looks very clean. But the package is a weird land-grid thing. LTC has some pcb parts ...


MOSFET breakdown prevention in a boost converter

Started by Anonymous in sci.electronics.design8 years ago 6 replies

Hello: I am designing a boost converter, and I am uncertain whether I need to take specific measures (and which) to protect the main switch...

Hello: I am designing a boost converter, and I am uncertain whether I need to take specific measures (and which) to protect the main switch MOSFET from the drain-source voltage breakdown. The fet is incorporated in the switcher IC, and has the maximum voltage rating of 60V. I want the converter's output voltage about 55V. Now, if one takes into account the parasitic inductance of the PCB t...


Need tiny switcher 3.3v in 2.5vout 300ma

Started by Yzordderrex in sci.electronics.design8 years ago 4 replies

Title says it all. Application is cell phone and I need more efficiency. I'm using a LDO now. I can use TI, Maxim,LT, national, Micrel. Boss...

Title says it all. Application is cell phone and I need more efficiency. I'm using a LDO now. I can use TI, Maxim,LT, national, Micrel. Boss wants answer NOW! regards, Bob N9NEO


SWITCHER DESIGN Q.

Started by Anonymous in sci.electronics.design8 years ago 8 replies

I need a 12V to 24V stepup boost converter at 80 AMPS (very low duty cycle, 1 second on, 100 seconds off) So far the inductor looks...

I need a 12V to 24V stepup boost converter at 80 AMPS (very low duty cycle, 1 second on, 100 seconds off) So far the inductor looks like: F= 200 Khz L = 7-10uH So any Idea where to get kilowatt class inductor cores in small amounts for prototyping? Steve


spread-spectrum switcher

Started by John Larkin in sci.electronics.design8 years ago 19 replies

This is cool... ftp://jjlarkin.lmi.net/SS_LTC3411.zip It would be even better if this Aeroflex spectrum analyzer wasn't so multiply...

This is cool... ftp://jjlarkin.lmi.net/SS_LTC3411.zip It would be even better if this Aeroflex spectrum analyzer wasn't so multiply brain-damaged. If I could set the RBW below 1 KHz, the spread thing would be even lower. But the idiot thing hangs up if I try that. It would be nice if it spoke English, too. John


Help ID Wallwart Switcher or Linear

Started by amdx in sci.electronics.design8 years ago 11 replies

Hi guys, I want to know if this is a switching supply or a linear...

Hi guys, I want to know if this is a switching supply or a linear regulator. http://www.monstermarketplace.com/Electronics/Landing2900a2344.html http://www.amazon.com/PHC-2200W-PHC-2200W/dp/B000VA359W This involves running a pump, a thermostatic controlled circuit switches on the PHC-2200w and that drives the pump. Have had a problem with the thermostatic controlled circuit and man...


Wiring and EMC

Started by Raveninghorde in sci.electronics.design8 years ago

I spent Wednesday on site looking at an EMC problem. We supply the boards and our customer builds them into a variety of units. Harmonics of...

I spent Wednesday on site looking at an EMC problem. We supply the boards and our customer builds them into a variety of units. Harmonics of an LM2675 simple switcher running at 260kHz were getting out onto the mains. 1.5MHz was about 0.2dB out of spec and several harmonics were within 6dB of the limit. The problem was the same as one I had identified about 4 years ago. On the controller...


triple switcher

Started by John Larkin in sci.electronics.design8 years ago 30 replies

We keep running into the requirement to turn +12 or +5 volts into 3.3, 1.2 (fpga core), and usually a third voltage, 1.8 (for drams) or...

We keep running into the requirement to turn +12 or +5 volts into 3.3, 1.2 (fpga core), and usually a third voltage, 1.8 (for drams) or 2.5 (fpga Vccint). We'd like to consolidate this to save board area and general complexity. Any suggestions? LTM4615 looks interesting, a bit expensive but very small. http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1424,P89092 And ...


day shot to hell

Started by John Larkin in sci.electronics.design8 years ago 48 replies

OK, I just got the first board from production this morning, for this spectroscopy controller thing. ftp://jjlarkin.lmi.net/First.JPG It...

OK, I just got the first board from production this morning, for this spectroscopy controller thing. ftp://jjlarkin.lmi.net/First.JPG It gets 12 volts in, which runs an LTM8023 switcher brick to make 3.3 volts. The 3.3 runs most of the logic on the board (including a Spartan 6 and a PLX PCIe bridge, both BGAs) and also drives four secondary switchers and some LDOs to make 1.2, 1.5, 1.8, ...


Problem with LM3150

Started by Raveninghorde in sci.electronics.design8 years ago 15 replies

I'm debugging a buck converter using an LM3150 simple switcher. The switching FET is an N type, FDP060AN08A0 and gets hotter...

I'm debugging a buck converter using an LM3150 simple switcher. The switching FET is an N type, FDP060AN08A0 and gets hotter than anticipated. The gate drive voltage is generated using a 470n X7R boost capacitor as specified in the data sheet. However the gate-source pulses are only about 4.5V peak which means the FET is not being switched on hard enough. 4.5V gate drive appears wron...


LTSpice Automation

Started by Tim Wescott in sci.electronics.design8 years ago 76 replies

Does LTSpice have much in the way of automation capabilities? I'm working on a switcher design, half in mathemagic land, half in grotty old...

Does LTSpice have much in the way of automation capabilities? I'm working on a switcher design, half in mathemagic land, half in grotty old real circuits land -- I want to simulate the controller with PWM voltages, and look at how the circuit responds. So I'd like to run the circuit with a bunch of different duty cycles. But it's a complex circuit, so I need a bunch of different PWM's...


Noise in electrolytic capacitors

Started by Nemo in sci.electronics.design8 years ago 25 replies

I am trying to evaluate whether to use tantalum versus OS-CON aluminium electrolytics as the output decouplers for some linear postregulators...

I am trying to evaluate whether to use tantalum versus OS-CON aluminium electrolytics as the output decouplers for some linear postregulators after a (relatively low noise) switcher. This is for a high gain amplifier that will be operating down to audio frequencies. I've come across references to aluminium electrolytics being noisy, but no firm details (kind of odd as there are lots of d...