12V DC-DC converter square wave problems (and solution)

Started by P E Schoen in sci.electronics.design5 years ago 3 replies

In a previous post I mentioned a small DC-DC converter using 12 VDC and an IRS24531 driving two dual MOSFETs FDS6930B and two custom built...

In a previous post I mentioned a small DC-DC converter using 12 VDC and an IRS24531 driving two dual MOSFETs FDS6930B and two custom built ferrite transformers with an E187 core. I tested one set of transformers that I built, which have about 348 uH inductance and 25 H leakage inductance. The ones in this board have about 500 uH and only 2 H leakage. I wanted to see the current draw of ...


Resonant power converter

Started by Andrew Holme in sci.electronics.design5 years ago 8 replies

Hello all, long time no post from me. I'm still alive and I see a lot of familiar names are still here. I'm working on a resonant power...

Hello all, long time no post from me. I'm still alive and I see a lot of familiar names are still here. I'm working on a resonant power converter design for a consumer LED lighting application. I used Bourns 33mH inductor part number RLB9012-323KL which is rated for a maximum DC current of 90mA. In my application it is carrying a sinusoidal AC current of 85mA peak at a frequency


Forward converter question

Started by vkj in sci.electronics.design10 years ago 13 replies

I built a 2-switch forward converter, whcih worked OK but the IGBT switches (IRG4BC20U) failed after a few months (probably because of...

I built a 2-switch forward converter, whcih worked OK but the IGBT switches (IRG4BC20U) failed after a few months (probably because of inadequate heatsinking). WHen I replaced them I must have indavertently stripped the track on the gate of the upper transistor. This made the gate float. When I powered up, it worked at low output but near the max load the upper transistor got fried and the fuse...


A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje in sci.electronics.design7 years ago

A 2.4GHz to 1.5 GHz down converter Its working! This is basically a VCO, mixer, and voltage stabilizer. Added the resisistors and...

A 2.4GHz to 1.5 GHz down converter Its working! This is basically a VCO, mixer, and voltage stabilizer. Added the resisistors and capacitators, some not wireless connections too: http://panteltje.com/pub/testing_2.4_GHz_to_1.5_GHz_down_converter_IMG_4655.JPG Note the disconnected coil, its basically a protection for DC coming back via the LNB cable from the sat receiver in case a ...


Ultra-low power switching boost converter - in a DIP

Started by Peabody in sci.electronics.design5 years ago 24 replies

For a hobby project, I've found the perfect part for converting battery power to a very low current (2 ma at most) 28V power supply. And that...

For a hobby project, I've found the perfect part for converting battery power to a very low current (2 ma at most) 28V power supply. And that is the Linear Technologies LT8410-1 "Ultralow Power Boost Converter". The problem is that the only package available is a tiny surface mount chip that's 2 x 2 millimeters, which effectively makes it impossible to deal with using a soldering iron....


CPU fan buck converter, miniature

Started by Winfield Hill in sci.electronics.design2 years ago 30 replies

https://www.dropbox.com/s/wttdn9r8np3o0t6/buck_CPU-fan.JPG?dl=0 I had finished a new PCB version of my compact 250A analog pulser, with a...

https://www.dropbox.com/s/wttdn9r8np3o0t6/buck_CPU-fan.JPG?dl=0 I had finished a new PCB version of my compact 250A analog pulser, with a newly-added CPU fan. The fan was powered with an 78L12, hey, there wasn't room for much else. But it was obvious its 300mA would overheat the TO-92 regulator, plus what a waste of power! I needed to fit a buck converter. This called for a SOT-...


Zener Diode Selection

Started by Anonymous in sci.electronics.design9 years ago 4 replies

Hi, DC to DC Converter:=20 http://cds.linear.com/docs/Datasheet/3970fb.pdf Zener...

Hi, DC to DC Converter:=20 http://cds.linear.com/docs/Datasheet/3970fb.pdf Zener Diode:=20 http://www.digikey.com/product-detail/en/1N5364B-TP/1N5364BTPMSCT-ND/111430= 6 The DC to DC converter can handle input voltage upto 40V. DC to DC convert= er is configured to output 5V. I do not want the input voltage to exceed 33= Volts. That is why I am using a 33V Zener. But I think that...


A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje in sci.electronics.design7 years ago

A 2.4GHz to 1.5 GHz down converter layout This is basically a VCO, mixer, and voltage stabilizer: ...

A 2.4GHz to 1.5 GHz down converter layout This is basically a VCO, mixer, and voltage stabilizer: http://panteltje.com/pub/2.4_GHz_to_1.5_GHz_converter_IMG_4645.JPG The screw in the trimpot will allow fine adjustment of the output frequency from outside the box. After using this 964 MHz VCO in several projects, finally a pad (VCO in) broke off. Had to open it... removed the cover: ...


Using a DMM to measure output isolation/crosstalk

Started by Chuoiujk in sci.electronics.design5 years ago 3 replies

I'm making some PCB's that have some DC to DC converters on them with three 5 Volt converters, one 15 volt converter, and a converter with +/- 12...

I'm making some PCB's that have some DC to DC converters on them with three 5 Volt converters, one 15 volt converter, and a converter with +/- 12 volts DC. On the PCB the output pins are in a connector that are fairly close to each other. I want to make sure that there is isolation between all the supply outputs. The +/-12 supply shares the same common between them, but I"ll have t


A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje in sci.electronics.design7 years ago

I wrote: > A 2.4GHz to 1.5 GHz down converter > > Its working! > > > Cool, > now tune the sat receiver to 10,600,000,000 Hz higher...

I wrote: > A 2.4GHz to 1.5 GHz down converter > > Its working! > > > Cool, > now tune the sat receiver to 10,600,000,000 Hz higher because it assumes a LNB LO, makes 12041,474,000 Hz, we should see a signal: > http://panteltje.com/pub/anything_transmitter_OK.gif > indeed, and recording works too. > > It is not completely clean as the other sat receiver shows (that one one has lock problems


MC34063 Step-down Converter Heating Problem

Started by Anand P. Paralkar in sci.electronics.design10 years ago 21 replies

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown...

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown here: http://www.eleccircuit.com/wp-content/uploads/2008/01/ipod-mp3-player-charger-by-mc34063.jpg My circuit does not have the Zener, output side LED and input side protection diodes (TVS1 and D2 in the circuit). The rest of the circuit is quite similar. The...


Best way to solder prototype pcb with thermal-pad ICs?

Started by Winfield Hill in sci.electronics.design2 years ago 27 replies

I'm struggling with issues prototyping PCBs having ICs with a thermal pad. I assembled a new 100-volt buck converter powering a 12V fan, see...

I'm struggling with issues prototyping PCBs having ICs with a thermal pad. I assembled a new 100-volt buck converter powering a 12V fan, see schematic: https://www.dropbox.com/s/ypvtp2z74nudps7/RIS-796_3_Fan-supply_sch.JPG?dl=0 The circuit uses the elegant NSC LM5163, a 100V 0.5A 1MHz converter in an SO-8 PowerPad package. On the pcb layout, I had extended the thermal pad beyond ...


Small SMD xformer for a forward converter with double isolation

Started by Klaus Kragelund in sci.electronics.design9 years ago 21 replies

Hi I need a small SMD transformer for a 100mW SMPS. It will be running in a single switch forward converter at about 200kHz. This pulse...

Hi I need a small SMD transformer for a 100mW SMPS. It will be running in a single switch forward converter at about 200kHz. This pulse part looks like it fits the bill: http://ww2.pulseeng.com/products/datasheets/T678.pdf But, it isn't double isolated (need working voltage isolation of 300V). Anyone have a hint to something simelar that is double isolated? Thanks Klaus


S2405 Cheap scope, new working software or serial protocol to write my own

Started by M Philbrook in sci.electronics.design7 years ago 4 replies

I have a cheap hand held DMM scope meter that I used mostly for very basic things..S2405 model rebranded under serveral names. Today I...

I have a cheap hand held DMM scope meter that I used mostly for very basic things..S2405 model rebranded under serveral names. Today I installed the old software to a windows XP machine using a USB to Serial converter. The converter works fine on the machine however, the supplied software, which is 16 bit land does not seem to communication with the USB driver, it knows it exist bu...


A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje in sci.electronics.design7 years ago

A 2.4GHz to 1.5 GHz down converter Channel 9 Wifi wireless access point spectrum: http://panteltje.com/pub/wap_spectrum.gif WiFi...

A 2.4GHz to 1.5 GHz down converter Channel 9 Wifi wireless access point spectrum: http://panteltje.com/pub/wap_spectrum.gif WiFi channel 9 should be around 2452 MHz, and that is where I find it. Cool. This version of the xpsa spectrum analyzer still needs for GUI improvement b4 release. Circuit diagram, as some can see simplicty works too: http://panteltje.com/pub/2.4_GHz...


add one resistor, quiet ugly smps ADC noise

Started by Winfield Hill in sci.electronics.design3 years ago 46 replies

Switching converters and sensitive SAR ADCs don't go well together. Consider a 3.7 Li-ion to 14V boost converter, switching 400mA current...

Switching converters and sensitive SAR ADCs don't go well together. Consider a 3.7 Li-ion to 14V boost converter, switching 400mA current ramps at 500kHz. Add a 16-bit ADC, which takes 2us to sampling a signal, and completes its conversion in 15us. A large fraction of the ADC samples are degraded by SMPS switching noise. The boost converter, a TPS61040, has an enable input, but if...


24V to 500-1000V, 20W floating DC-DC converter

Started by Matt B in sci.electronics.design1 year ago 105 replies

I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter. My specs...

I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter. My specs are: Input: 24-28V Output voltage: 500-1000V adjustable via control signal Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W) I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure


Buck step down convertor uses a lot of power?

Started by AK in sci.electronics.design3 years ago 34 replies

I have a DC-DC Buck Step Down Converter Module LM2596 Voltage Regulator set to supply 3.0 volts to an atomic clock using a 8 Ah 12 V battery. The...

I have a DC-DC Buck Step Down Converter Module LM2596 Voltage Regulator set to supply 3.0 volts to an atomic clock using a 8 Ah 12 V battery. The clock normally uses 2 AA batteries. "https://www.ebay.com/itm/DC-DC-Buck-Step-Down-Converter-Module-LM2596-Voltage-Regulator-Led-Vol tmeter-M3/301724177038?epid=10003955778&hash=item464029928e:g:bAwAAOSwdsFUNdsC" The battery started out at 12.07 V.


another goofy boost converter architecture

Started by John Larkin in sci.electronics.design8 years ago 97 replies

Sort of a hybrid of a flyback and a sepic. I call it a skeptic converter. I don't trust the efficiency calculation, especially when it goes...

Sort of a hybrid of a flyback and a sepic. I call it a skeptic converter. I don't trust the efficiency calculation, especially when it goes over 100%. Version 4 SHEET 1 1920 1092 WIRE 224 96 96 96 WIRE -48 144 -96 144 WIRE -16 144 -48 144 WIRE 96 144 96 96 WIRE 240 144 96 144 WIRE 320 144 240 144 WIRE 464 144 400 144 WIRE 528 144 464 144 WIRE 656 144 608 144 WIRE 912 144 864 1...