Thursday, 15 May 2014

TPA3106D1 4 channel amplifier with active crossover minidsp Part 2



Lately I have been a bit busy and soldered all four boards and tested them. There was no problem with any of them so lucky me:). Also I decided that casing for this amplifier will be open type, made of black anodized aluminum.

Bottom side of the board.


On the top side there will be only wires from the board, this also makes easier board stacking. 

Hand soldered HLQFP32 package. 


  
Last pic: Only to give you idea how the amplifier will look in the end.


Wednesday, 16 April 2014

Arduino pro mini V2 PCBs arrived!

So PCB arrived in today. I just had enough time to solder it and to make some pictures so that you can get better idea. In a few days I will show you how to use this "under shield" and what is the purpose of it. 


Top side


Bottom side

Completed board without screw terminals


Markings of arduino pins and solder jumpers
 The "other" side


Pins that can be used for servos, sensors etc...


Completed board with screw terminals








Friday, 11 April 2014

TPA3106D1 4 channel amplifier with active crossover


So I started a new project, creating 4 channel amplifier with active crossover to use it with speakers XTZ 93.23. I will be using TPA3106D1 as I have some of these PCBs at home and I really like this small amplifier. It has all the protections you need and the sound is also great, especially lower end of the sound spectrum. I am still deciding what to use for crossover, 2way opamp based circuit or miniDSP. I believe that discrete design may sound better but you need to modify PCB every time you want to change crossover filter, while on miniDSP you just plug in USB, go.

 4 PCBs populated with some components


Most of the components are SMD size 0805


This is how PCBs will be mounted. There where you can see some of the space left, it will be mounted regulated power supply board using low noise LDO.


These stand offs are a bit too short, because the coils are almost touching the other PCB and coupling caps won't fit in, so I will replace them with 15mm.

Friday, 28 March 2014

USB Isolator ADUM4160

My little project how to improve sound of my ODAC. I have made usb isolator that contains ADUM4160 with shunt regulator. I have used schematic from salas @ diyaudio and modified it a bit. I changed those 2sk170 with BF862 which are more easily obtainable and they also have smaller package, so that I was able to create really small PCB. As picture says 1000 words, here are some pics.

 Power supply on the left, ODAC in the bottom and USB isolator in the upper left side.



 Almost completed casing. I still need to create top cover of the box.



ODAC is connected to the USB isolator through modified usb cable, so that at any time sound card can be removed or any other device can be used. Since connection is very short it is not critical to use remote sensing from the shunt regulator.



Shunt regulator configured to configured to output 300mA of current but it can supply up to 500mA with small heat sink.



 Top PCB



Bottom PCB

Wednesday, 5 March 2014

Arduino pro mini V2 board

This is something I came up with while I was working on a project. Every time I am working with Arduino in the end of a project I always need a PCB, many times even more than one. Option to use protoboard and arduino uno is quite time consuming and rather expensive (comparing to the arduino pro mini or just Atmega328).I have developed PCB that can fit Arduino pro mini 5V, from Sparkfun and from Ebay(<- this one is really cheap 2.80USD), there you can find on board PSU with LM7805, which can be omitted if you already have regulated +5V, screw terminals for 12 pins, and 8 pins are accessible via pin headers. Pins with screw terminals can be configured as inputs or outputs via solder jumpers, protective resistors are also available, 8 pins are positioned in a way that they can be used with most of the servos. Programming of the arduino pro mini can be done through on board ISP or via RS232 which is directly on Arduino pro mini. Before I receive real PCBs, here are pictures of top and bottom side made in eagleup.
Top Side

Bottom side

You may be wondering why on the bottom side of the PCB is written ALMOST SQUARE, well I couldn't think of any good name so I got idea from dimension which is 56mm * 62mm.


Monday, 17 February 2014

ALOG - Arduino based support board

I designed this board, because I always had problem when I wanted to access arduino shield that was is the middle, not just the one that was on top. Now I can access three shields and stack even more. Also I was able to put on bigger protoboard and not just the one that is usually found on arduino shield. Because arduino is turned upside down, I can't access reset button and also LED pin13 isn't visible, so these two options are also on board.





There is also programmer socket for all attiny microcontrollers which can be programed via arduino and on onboard isp socket. 

Specification:
Compatible with Mega 1280 / 2560 / ADK / UNO / NANO
Support 3 shields directly on board, if you stack them then you're not limited
OnBoard dip sockets for programing via Arduino for attiny24/44/84, attiny13/15/25/45/85, attiny2313/4313, also includes 6pin ISP connector for other programmers.
All the pins are marked on the board. 
You can use bigger protoboard.
Easy accessible reset button
LED on pin13 is also present on the board.  
Size: 200x150mm