Power Supply

Instead of using wall transformers to power my equipment, I decided to see if I could easily build a variable power supply. This way I can add the same connectors to the hardware and use them with the same power supply. I had an old power adapter from a HP printer laying around. I like to try and use old hardware to build new things. It gives off 19 volts and 7.1 amps. So I started looking for a way to control/vary the power coming from the adapter.So I picked up this DC DC Buck Converter CC CV 50V 5A Power Module.

Components for Power Supply

Power Supply Working

Now I don't have to have all these different wall transformers taking up space. I intend to either build a box from some plastic I have laying around or maybe 3D print the case. I will come back to it when it is done.

Media Pump

Using a Syringe Filter to Sterilize Media:

Syringe and Filter

I picked up some syringe filters from Amazon figuring I could use a syringe to pass my media or water through the filter. As seen in photo the filter screws on to the top of syringe. This filter membrane has a pore size of .22 micrometers. This should easily sterilize the fluids.

Parts

 

Thinking there must be an easier way to run the media or water through the filter I picked up a 12V DC DIY Peristaltic Liquid Pump from Amazon. As seen in this image as well as the pump I picked up air hose tubing and airline tubing connectors from a pet store. The connectors allows different sized tubing to fit together.

Fitting to hold filter

I had a medical drop administration set I found at a flee market. This has the same type of connection as the syringe tip has, allowing the filter to screw on. As seen in the above image.

Unit put together

In the final image you can see the whole unit put together. I am using a 12 volt wall adapter hooked up to the motor speed controller (previous project) to control the pump motor. The filter holder was made with a 1/4 inch dowel and clothes pin glued together.

I pump the fluids through the system slowly as to hopefully not cause a big mess if it ever backs up. I intend to mount the pump into a weighted box so I don't set it up when I need to use it.

Motor Speed Controller

I found this motor speed controller module at an electronics surplus store. This will allow me to build a controller module that I am able to control more than one devise by just plugging and unplugging each device.

 

 

 

Parts Used in Build

 

As can be seen in the first image there is the controller, case for the controller, wire, control knob, male power connector (black and green) and female power connector (black and green).

 

 

 

Put Together and Working

 

 

In the second image you see it put together. I ended up using 2 female power connectors. It was very easy to put together. I connected a DC motor to test how it works. I am very pleased with the device. The power connectors are labelled with 'M' for motor output and 'P' for power input. Using these female connectors I am now able to connect different power adapters(3v - 12v).

The power connectors(found at an electronics surplus store) are also a great find. With these I can create different connectors and adapters. People are always throwing unused power adapters at me so now I can use them no matter what end they have. Wires are screwed in at one end of the connector. Where the wires connect it is labeled with either '+' or '-'. So if you find any get some.

 Second-Hand Store Finds

Second-hand stores can be a great place to find lab equipment and science kits. Though it is a hit or miss. Many times there is nothing to be had there. The biggest drawback can be the cost of the items. Some places charge outrageous prices for items. So be careful when looking and buying.

I found some electronic equipment I intend to use in some of my experiments.

1) A SOAR Corp. analog CRT based oscilloscope. From the simple tests I have done with it, it seems to be working fine.

 

 

Oscilloscope

2) A Cenco A.C. volt meter.

A.C. Meter

3) A electronic breadboard. To this I had to add the binding posts myself. Luckily I had some in my lab. The posts did not fit the holes. I did not want to buy any new ones so I designed and 3D printed fittings for the holes that the posts fit into. You can see the yellow fittings under the posts.

Breadboard

For less than $30 I picked up some useful equipment for my lab.

Maker Spaces

Maker spaces or hacker spaces(as some are called) are a great place to meet people and learn from them as well.

From spaces.makerspace.com/

"""
What’s a Makerspace?

To describe them simply, makerspaces are community centers with tools. Makerspaces combine manufacturing equipment, community, and education for the purposes of enabling community members to design, prototype and create manufactured works that wouldn’t be possible to create with the resources available to individuals working alone. These spaces can take the form of loosely-organized individuals sharing space and tools, for-profit companies, non-profit corporations, organizations affiliated with or hosted within schools, universities or libraries, and more. All are united in the purpose of providing access to equipment, community, and education, and all are unique in exactly how they are arranged to fit the purposes of the community they serve.

"""

They have tools from hand tools to drill presses to 3D printers to CNC machines to laser cutters. Some are even biological groups opening up spaces for people with that interest to do experiments with the maker spaces equipment and supplies.

Most maker spaces have a membership fee which can be costly, but I believe that many have open house days where you can visit the spaces and even get help with your projects.

I belong to the one in my city and have built different projects there for my lab. In one of my next posts I will be discussing some of the pieces that I have 3D printed at my maker space. I don't have a 3D printer but there is one at my maker space. There is so much different expertise there to help with electronics and programming, etc. I am glad I found this space.

If you don't have tools or space to work in, need help in learning how to use an arduino, etc. you should look into one today.

You can look for a space near you at:

http://hackerspaces.org/wiki/List_of_Hacker_Spaces

or

google "hacker spaces", "maker spaces" your "city".

The Arduino

The Arduino

I have been looking at the Arduino for some time. I finally picked one up, as well as the first edition of "Getting Started with Arduino" by Massimo Banzi. This seems to be a simple and inexpensive way to learn and to use a micro controller. A way to connect different sensors to a computer. Just great for the home lab. It is an open source electronics prototyping platform. You can purchase one already built or you can get the parts and put it together yourself. The Arduino receives input from a variety of sensors, which can then control lights, motors, and other actuators.

There are many books on the arduino. I have just the one, "Getting Started with Arduino" by Massimo Banzi.

I will post arduino lab projects as I build them. I am looking into a spectrometer, digital thermometer, pH meter, etc. So stay tuned. But for the time being look at these websites, become familiar with the arduino and enjoy.

The home page for the Arduino can be found here:

www.arduino.cc

and the Getting Started with Arduino page is:

arduino.cc/en/Guide/HomePage

Another Beginners Arduino Tutorial can be found here:

www.ladyada.net/learn/arduino/

A project site:

www.practicalarduino.com/projects