PCB from China 2

Got a new board from Dirt Cheap Dirty Boards http://dirtypcbs.com/.
here are some snap shots compared to our milled one on the T-Tech Mill

Looks great, again Dirt Cheap Dirty Boards came though with flying colours, this time I shipped DHL Hong Kong and got the boards exactly one week from the board house. Much better than my last order.

Problems to fix next time:

1. There was one via that is shorted that it's not suppose to, but not the board house fault, it is touching in my design, see below for a screen shot. easy fix with an xacto.

2. Forgot to label components on top silk screen

3. Nice thing to do is move buzzer to opposite side of arduino, using top layer. so far all my designs have been single layer.

Things Learned:


1. Board house can silk screen on both sides.

2. If the pads are touching they will follow design exact.

3. Board outline is on outside edge of midlayer, unlike the mill machine that is centred on midlayer, you can see the size difference in the above photo.

4. Board house can make any size under 100mm x 100mm my board is 71.5mm x 57mm exact to design. I though that it would have been 100x100 default.


 

Semi Automatic Paddle Practice Oscillator

This circuit is a Semi Automatic Paddle Practice Oscillator, I built to practice Morse code. It' similar to the paddle key for the ICOM IC-718. Here is the video

This is different than a standard practice straight key, like my home made paddle? 

It is Arduino compatible, I like to use a 6 pin header and a FTDI cable. It a lot easier to breadboard circuits.

Schematic:

PCB Board Design

Coming Soon!

Here is the Code ******************************************

int outPin = 9;

unsigned int frequency = 400;

unsigned long dotDuration = 60;

unsigned long dashDuration = dotDuration * 3;

int dotPin = 7;

int dashPin = 8;

void setup() {

pinMode(dotPin, INPUT);

pinMode(dashPin, INPUT);

}

void loop() {

int dotVal=HIGH;

int dashVal=HIGH;

dotVal = digitalRead(dotPin);

dashVal = digitalRead(dashPin);

if (dotVal==LOW)

{

tone(outPin, frequency, dotDuration);

delay (200);

}

if (dashVal==LOW)

{

tone(outPin, frequency, dashDuration);

delay (400);

}

}

Emptiness of a vacuum

AMPEG Valve amp I'm working on, more to come stay tuned......

Mega Hurts

This project is a 1 Hertz reference clock signal for digital and binary clocks, some of our older projects used the 60 HZ line frequency as a clock reference, the problem with this is after the power company deregulation they no longer have a tight frequency standard, the power company use to be 60 Hz (+/- 1 HZ).
Now it's all over the place, I measured at my house anywhere from 55 to 70 HZ, no wonder my old clock was gaining and losing time.

Here is the schematic

Photos

Here is the schematic of the binary clock we use

 

Notice that coming off the secondary of the transformer it feed into a 4040 and divides down by 60, pin4 of the 7414 is 1 Hz.

Projects on Steroids II

This project details a small & simple, but very powerful USB charger for your mp3 player, camera, cell phone, and just about any other gadget you can plug into a USB port to charge!

The USB charger that runs off 3 volt Boost regulator. this one is a twist with two "D" Cell. Does not work with Apple i"whatever", for apple you need to set 2 voltages on D+ and D- pins this will set your charge rate.

Projects on Steroids

Finnaly I can post again after finishing my last class.

Here are a couple of project I've been working on.

First is a 40 amp triac phase control for my electric water heater, this was built so I could reduce the wattage of the hot water heater, this was done so I could run the heater off my genset if we had power loss. Yes it works! and yes it takes longer to heat the water but it does not tax my genset. If I hooked it directly up to the genset it would be at it's maximum wattage rating. I have cut the power in half to around 2KW. Why not use a diode? Well that would tax one phase of the genset more than the other not a balanced load, by using the triac I can control both sides of the sinewave. Photo are below

I used the guts of a dimmer switch and swapped traics, you can still see the old one mounted next to the pot. The triac is rated for 40 amps or 9600watts, the heater has a max of 4500 watts. The heat sink is off of a solid state relay. I ran without a heat sink and the box got warm to the touch so I over killed the heat sink. Out of the box it min pot resistance I run about 2100 watts, at max 4000 watts. Used 10 AWG solid wire soldered directly to MT1 and MT2.