Power Electronics Top Talks in August on EDABoard.com forums

Peer-to-peer, engineer-to-engineer questions and answers from the EDABoard.com engineering community around power electronics. Click the “Read more” link and follow the entire conversation and maybe add your two cents by logging in to EDAboard.com

SPWM converter MOSFET failure – I am currently working in this circuit of an SPWM inverter and I keep having my MOSFETsburningg after each time I connect the center tap to the transformer. I am running out of ideas, mosfets and…money. Any suggestions why my mosfets burn? Read more

MOSFET gets hot in 3-phase inverter circuit – I am trying to build a 1KW bldc inverter circuit.
I used atmel328p processor, gate driver and 12 mosfets. The mosfets swiches good, but when i connected to 1kW motor (at 20v and 10amp supply) the MOSFET gets heated up above 60°C. The circuit work fine for low watts motors but not for high power motor (1KW). Read more

Fixed voltage linear regulators running way over – I am building an electronic module for use in a car. The main use is data transfer over CAN bus. The input power is ignition switched 12V, and I have two linear voltage regulators for 5V and 3.3V. The GPS module and VR conditioner circuit appear to work properly. The thermocouple, RS232 and ADC module are untested. I would like to figure out the 3.3V overvoltage before I hook up a microcontroller.  Read more

Current transformer – magnetizing current –  I am designing a current transformer (CT) to sense the current that is flowing in every single switch for a DC-DC converter. The converter is going to be built through a push-pull topology, and it has to deliver 200 W @200V. The input voltage is 24 V. The MOSFETs that I chose can deal up to 50 A.  Read more

Buck/boost converter and battery charger –  I have designed and implemented the hardware of a DC/DC buck boost converter and charger with the IC LTC4020. However, I am not getting the output as desired 12 V DC, instead of getting the output as 0 V. Apparently, the system does not work. Read more

Stabilising an ON/OFF controlled SMPS – We designed and laid out a 10W, offline, isolated flyback converter using the TNY287 controller as in the attached schematic. We were not allowed to use any electrolytic capacitors. We only have room for 30uF of ceramic capacitance on the output. The output has a 4V pkpk oscillation on it at some 4kHz but this is solved when we use the RC network R4 and C3 as in the schematic. TNY287 is an ON/OFF controller, and the manufacturer recommends high levels of electrolytic capacitance on the output. In our case, the manufacturer software program (PI Expert) recommends 250uF of electrolytic capacitance but we are just not allowed to use that and we can only fit 30uF on the board. Read more

Topologies of converter in brick DC-DC converter – I would like to know what topologies are commonly used in 600W DC-DC converter (48- to 72V Input; Output at 48 V) brick converters commercially available in market. Is there any reference material for the same?  Read more

Potted electrolytic capacitor will last longer? –  The following Philips Xitanium LED driver has a big “wet” electrolytic capacitor in it and several smaller ones, But they are all totally surrounded in potting compound. Do you believe that this will make them last longer than if they were not buried in potting compound? Read more

Triac dimmer circuit firing parasitically – I try to build the following triac dimmer which controls the power input to a 2 KW 28 KHz ultrasonic inverter. The ISIS circuit detects the zero crossing of the mains and I divide the 180 degrees of sinus voltage into 100 everything is fine until the firing angle is above 80%. Read more

 

Read SL-91369-monitor via UART – I’m using Spacelabs 91369 UltraView SL Patient Monitor 241qux06. I want to read it through serial using max3232 and Orange Pi. How can I read it? Read more