Switching Power Adaptor for Desktop

One of the switching power adaptors for desktop is so called SPU63-105, which has an output of 75 WATTS of rated power. The good thing about in this adaptor is that it has an input voltage range of 90 – 264 VAC and a frequency range of 47 – 63 Hz.  In addition with this, 88% of efficiency and employs a convection cooling mechanism to facilitate heat dissipation of the system.  You can check to some features of this desktop switching power adapter.

Medical Grade Power Supply

I saw a power supply that was design by medical purposes and that was PMMX300S-12E.  This device is really cool because it features a Power Factor Correction (PFC), which has a power factor of 0.95. This Power Factor Correction (PFC) has capable of delivering 300 W of rated power with a voltage output of 12 V and a current output of 25 Ampere. Safety features of the PMMX300S-12E include over temperature, over current and short circuit protection.

Check the features of Medical Grade Power Supply PMMX300S-12E.

Power Factor Correction

Doing a research about coil to use into my latest coil project. In my circuit design that I would like to create, I would like to use the Power factor correction as my reference which actually I need more research about it because I could not really understand it on how it will be functioning to my circuit diagram. Below are my specs in transformer using the Power factor correction.

• 240V to 120 V at 60 Hz    
• Single-phase 
•  Isolated 
• Low coupling 
• Single primary, dual secondaries

And my expected layouts to choose from are among on these 3 designs.

I was thinking also to use the 018 series, which is a family of passive Power Factor Correction (PFC) coils that includes both in sealed. The 018 series includes a line-up of nine (9) models that have different current rating ranging from 1 – 18 A. If you don’t have any idea about it then see the features of this 018 series for you to check.

• Sealed and open frame
• Laminated core type
• Low audible noise
• Compact and reliable PFC coils
• PVC leads and faston connection
• Specially designed to increase the power factor and reduce THD while maintaining low temperature rise during operation
• Low power losses to extend operational lifetime

FDMF5820DC Smart Power Stage

Have you done creating high current power stage circuit diagram using the FDMF5820DC? Recently, I decided to create one by following the diagram below with instruction of course.  It is the next generation family of Fairchild with fully optimized, ultra-compact, integrated MOSFET plus driver power stage solution for high-current, high frequency, synchronous buck, DC-DC applications.

Check some features of FDMF5820DC.

• Ultra-Compact 5 mm x 5 mm PQFN Copper-Clip Package with Flip Chip Low-Side MOSFET and Dual Cool Architecture

• High Current Handling: 60 A

• 3-State 3.3 V PWM Input Gate Driver

• Dynamic Resistance Mode for Low-Side Drive (LDRV) Slows Low-Side MOSFET during Negative Inductor Current Switching

• Auto DCM (Low-Side Gate Turn Off) Using ZCD# Input

• Thermal Monitor for Module Temperature Reporting

• Programmable Thermal Shutdown (P_THDN)

• HS-Short Detect Fault# / Shutdown

• Dual Mode Enable / Fault# Pin

• Internal Pull-Up and Pull-Down for ZCD# and EN Inputs, respectively

• Fairchild PowerTrench® MOSFETs for Clean Voltage Waveforms and Reduced Ringing

• Fairchild SyncFETTM Technology (Integrated Schottky Diode) in Low-Side MOSFET

• Integrated Bootstrap Schottky Diode

Encapsulated MicroVerter

I’m doing some research about the advantages of Encapsulated MicroVerter to be use in my circuit diagram project but upon doing my research I found out that there are many of them to choose from. 

I choose to use Encapsulated MicroVerter because of the auto recovery from OTP / OCP / OVP Circuits features that perfectly used in myproject. I choose this as well because I’m looking a second generation that high efficiency electrical power design and proprietary advanced thermal management. For more feature please read Encapsulated MicroVerter.

Solar Circuit Diagram

Just this morning a gleam idea that was pop up to my mind to create a solar circuit diagram and I want it simple and easy to understand to the newbies. After my coffee I went to my laptop table and start my research about this solar circuit diagram and after 2-3 hour of doing some research I found this cool site that maybe can help me. 

 You can see below the very basic small solar installation with connection for adding additional solar panels. 

The 20 Amp main fuse used can vary depending on the load from your whole system and whether or not an inverter and AC circuitry is added. After specification of the wiring I generally try to start with a lower fuse than is really needed, switch everything on for a few minutes then if the fuse is OK stay with that, but keep a spare correct higher value one handy just in case, changing it only after a thorough inspection of the system. It is just the way I am, if I am supposed to use a 2 Amp fuse I will probably be trying a 1 Amp fuse first on the principal stated above. 

 Always remember - The fuse should always be rated less than the wire/run it is protecting, the fuse must always be the weakest link! 

The small fuse without a value is determined by the nominal output from the solar panel(s) and the wire gauge used, for example a 27w panel has a nominal output of around 1.5 Amps so it would be best to fit a 2 to 3 Amp fuse after first using the correct wire run. This is worked out by Ohms law i.e. watts (27 w) ÷ volts (approx panel voltage 17.5 v) = Amps (1.5) hence the 2 to 3 Amp fuse.

If you have time you can check also my design of a battery charger schematics.

Problem Encounter in RS485 Circuit

I had designed a little board to interface USART to RS485 circuit that has two types of connection: one row of the DIP MAX232, or the ISP header for ATmega64-128-1281-2561 family. 

But after few hours of design, I had decided to improve the circuit, by adding automatic capabilities to the T/R signal, instead of using SCK from the ISP header.

After 2 hours of using Google doing some search for circuits that automatically switch T/R signal, I didn't find anything interesting about the problem I have. Only one circuit that uses a simple transistor and few resistors, but that doesn't satisfy me, since I'm not sure if I do switches off the transceiver too early after the last bit had been sent.

I must say that I have a little being lazy guy, since I'm asking for suggestions about that which I think it’s a good idea to ask some help from you guys because I know some of you may encounter same problem as I encounter right now.

My first bet would be to add a capacitor between T/R pins and ground or VCC to add some delay.

Has someone experience with this kind of circuits? Can you share your idea and thoughts about it or someone that can give advice about this?