2-channel computer speaker system (solar power part 4)

I found speakers that attached to the side of an old TV. They could be used with individual stands or bolted to the side of the TV. The amplifier inside the TV failed, but the speakers were fine. They sounded better than my previous computer speakers, and could be powered from my solar power system. So I decided to swap them out, and build a wooden stand to hold them. I used scrap wood from IKEA furniture that matched my desk surface, and old fence boards for the uprights.

 I also mounted a switch and an amplifier on the speaker stand.

The new speakers with stand are better because they take up less desk space, sound better, and use solar power.

Recycled Soap #5

After our annual summer vacation family road trip, I ended up with a whole bunch of tiny hotel bars of soap. I decided to combine them with a few from previous years that I had tinted, to make a larger ball of soap that would be easier to use. I used the same process as the previous batches. I shaved them into curls, chips and powder depending on the properties of each bar of soap. Some were ductile and some were brittle. I used a knife that I sharpened with a sharpening stone I bought on the trip.
I added water to make the bits stick together, shaped it into a ball, and set it aside to dry. I am interested to find out how much weight is lost as the water evaporates. The ball of soap is 7 degrees F below room temperature, which suggests that water is currently evaporating.

Power Supply- Beryllium Oxide Thermal Conductor

I recently visited my Great Uncle Mike, who has an amazing inventory of electronic parts in his workshop. I talked to him about some of my problems with past projects and how I'm still learning about electronics. One of the projects that could be improved is my bench power supply. When I first added the 3.3 volt rail, I used thermally conductive double stick tape to attach the regulator to the heat sink because I didn't know any better. It needs to be electrically isolated because the tab is connected to the output of the regulator instead of connected to ground. He suggested a much better solution- a beryllium oxide ceramic material. BeO is about as thermally conductive as copper, but not electrically conductive. He said that this type of material is not used much in consumer electronics because it is expensive and the dust from it is highly toxic. It might be more commonly used by the military or NASA.

pop socket repair

The cap to my pop socket phone holder broke. It was held on by 4 tabs that fit into small slots in the plastic.
I made a replacement cap out of three different pieces of wood. I glued it with wood glue and clamped it. Then I cut it with an adjustable hole saw. But forgot to account for shrinkage when sanding, so it's a bit small. sanded, clear coated, attached with tiny nails with heads large enough to stay in the slots. I also glued in a piece of dowel to fill the hole.

Tea Machine- Splash Shield

To protect the arduino and other electronics from being splashed, I added a cover made of clear plastic, this also helps support the switch box. It might look better with a slightly frosted plastic to hide the wiring, but for now I just used the clear plastic I already had from a large pretzel container.

Tea Machine- Indicator Light

The next addition to the tea machine is an indicator light that sits just under the coffee maker base. It has three 5mm LEDs, one for each time setting. The green is lit up from 3 and a half to 5 minutes, the yellow indicates 5-10 minutes, and the red is 10 plus minutes. The yellow has a white lens. I added 1000 ohm resistor, shared by all three LEDs.
The timing of the lights is controlled by the arduino. I added the code for the timing of each light. The pins needed to be configured as OUTPUT in order to send the correct current to the LEDs.

Tea Machine- Now with Robot Arm

My tea maker project is built around a basic coffee maker. I added 3 timers powered by an arduino uno. After the first 3.5 minutes, the contactor turns off the power to the coffee maker to stop dispensing hot water. After 5 minutes, a buzzer goes off. After 10 minutes, another beeper sounds.

This week, I replaced the AC adapter I was using with a power board. It has a common cathode dual diode, a capacitor and an LM7809.

The newest part I added is a servo motor attached to a bent plastic knife to take the tea bag out automatically after the first 3.5 minutes. I had started working on this 2 years ago, but now I have finally added the code needed to control the servo. The first test didn't go so well, jerking the tea bag out too quickly and splashing hot tea on the counter. To fix it, I could have changed the code to run the motor slower. Instead, I hung the tea bag closer to the end of the arm, and added a splash shield.

here is the code:
#include

Servo myservo;  // create servo object to control a servo
int pos = 0;    // variable to store the servo position
int loudPin = 12;               
int HotPin = 11;
int louderPin = 10;
void setup()
{
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  pinMode(loudPin, OUTPUT);
  pinMode(louderPin, OUTPUT);
   pinMode(HotPin, OUTPUT);// sets the digital pin as output
}

void loop()
{ for (pos = 90; pos <= 177; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);     
  digitalWrite(HotPin, HIGH); 
  delay(210069);                 
  digitalWrite(HotPin, LOW);
  for (pos = 177; pos >= 90; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);   
  delay(90000);
  digitalWrite(loudPin, HIGH); 
  delay(3000);
  digitalWrite(loudPin, LOW);
 delay(300000);
  digitalWrite(louderPin, HIGH); 
  delay(3000);
  digitalWrite(louderPin, LOW);
  delay(3000000000000000420);
}
}
}

Quick Connect Pressure Gauge

After replacing a failed regulator, I decided to reuse the old gauge from it in a project. I used a 1/8NPT27 tap to cut threads in the inside of a male Quick Connect fitting. Then I screwed the two parts together and wrapped electrical tape around it to provide a softer grip. (The tape is not for pressure or sealing leaks).

I can use the gauge to check the pressure coming from an air hose, without having to go look at the stock gauges on the air compressor. Our compressor stops at 120 psi, but the gauge can measure up to 160 psi.

Solar Power System Part 3- 2.2 Channel Speaker System

I have had an amplifier and speakers in my "lounge area" for a few years. I've changed speakers, amplifiers, and the power system a few times, but the basic set up is still the same. The  speakers I have now were part of a set of 5 that I bought at Goodwill. Now I finally have the speakers powered by my solar battery box.

The batteries are charged by the solar panel, and then connected to the amplifier, which is connected to 8 speakers. There are 4 speakers per channel, with 2 channels. I have 2 subwoofers and 2 full range drivers per channel. This creates a powerful, well-balanced sound in a small space. The amplifier is capable of putting more than 30 Watts into the speakers, but I rarely go above 1 Watt. Each of the full range drivers can handle 120 Watts. My original goal was to have a bed-shaking loud alarm clock powered by solar, but the alarm app wouldn't output at full volume and it wouldn't always turn on at the right time. 

I also added a laser indicator light so I remember to turn off the speakers when I leave the room or go to bed. If I leave it on, the speakers make random popping sounds that could damage them. The laser dot is projected onto one of the speakers. I got this idea from a hard drive light that projects onto the desk.

Impact Wrench Battery Rebuild

I bought an old Snap On impact wrench at a garage sale recently. It's a good brand that's usually too expensive for me to buy. It came with two batteries, but I thought even if I had to buy a new battery it might still be a good deal.
After testing it out for a couple of weeks, I found that one of the batteries wasn't holding a charge and the charger said it was bad. I attempted to charge it with a different charger, but it still wouldn't charge all the way. After looking at prices for the name brand battery pack, I decided to look at battery rebuild kits instead. The pre-assembled ones were still too expensive, so I decided to buy 12 individual sub C nickel cadmium cells and solder them together myself.
Opening the plastic case was straightforward, just requiring a T10 torx bit. I watched several Youtube videos on battery pack rebuilding so I knew what supplies I would need.

First, I arranged the cells in the same pattern as the original battery pack, and hot glued them together.
Then I used nickel plated steel strip to connect them. I was worried that soldering might make the cells too hot. The proper way to attach them would be with spot welds. Soldering did work, but the heat might shorten the lifespan of the cells. It was difficult to get the solder to stick in some spots, so I had to sand the ends of the cells

After I attached and connected the cells, I tested the fit in the original case and added a new piece of foam to the bottom. The cells seemed to fit well, but when I tried to slide the battery in and out of the tool, I found that the button on one side wouldn't release.  the negative connector was shifted slightly, so I had to take it apart again, and resolder one of the connections. After that, the buttons functioned perfectly. Now it holds a full charge.