Saturday, November 22, 2014

Homemade Modified Sine Wave Power Inverter(350/500w) on a Breadboard

I am very excited to have finally gotten this hefty little circuit working on a breadboard today. 

I first saw this on a You Tube video called Homemade Modified Sine Wave Power Inverter(350/500w) by electronicsNmore.

 
O.K.,  first I have to admit that I was not able to get it working the first time through. I had let it sit on the back burner while I worked on some other things. But, today, I gave it another shot, and am happy to see it working from a breadboard.

 The circuit was designed by John Parfrey, as is indicated in the schematic.



Homemade Modified Sine Wave Power Inverter(350/500w) by John Parfrey


Second time through, I wanted to test that it was functioning by leaving out the 7808 voltage regulator, just to make sure that it worked. After confirming that it did work, then I add the 7808 voltage regulator, upside down on the breadboard, simply because the schematic shows the input to pin #1 was to the right, and I wanted to visualize that. The remaining parts are laid out pretty much as the schematic has it.


There are at least two things that do not match to specifications (on my breadboard), the transformer and the 0.1uF electrolytic capacitor (to the left of the schematic). The design calls for a 10-0-10 center tapped transformer, and I am using a 12-0-12, 4 Amp transformer. Also, I do not have the 0.1uF electrolytic capacitor, and am currently using a 1uF electrolytic capacitor (until I can order the correct capacitor).


Otherwise, I am using the STP55NF06L mosfets, for the 500 watt version (as is shown in the schematic).

I did observe that the waveform is indeed a modified sine wave (using a 4 watt light bulb):

Modified Sine Wave from John Parfrey's Power Inverter design

You might also notice that the frequency is nowhere near the 60 Hz that I want it to be, indicating that the change to a 12-0-12 transformer may require less resistance than indicated in the schematic. You might note that ElectronicNMore YouTube video indicates that he is using an old microwave oven transformer, so the design can be modified successfully. Other factors that can affect frequency would be that I am using the 'cheap' version of the 4017, which does not operate as effectively as more expensive versions, and my battery amperage on this breadboard is minimal. (You can see from the breadboard photos that my power source is AA batteries. I also test with a 7 Amp Hour battery, and a 22 Amp Hour battery). A more powerful battery under a larger load would be more likely to deliver a different frequency.


Being relatively new at this, I think one of my initial problems was that I had not seen the breadboard on this one. So, I will add breadboard pics for others who may want to try it out.


Homemade Modified Sine Wave Power Inverter(350/500w) on a Breadboard
 
 Here is a close up view with the positive rail at the top:


Homemade Modified Sine Wave Power Inverter(350/500w) on a Breadboard02

Here is a view from the other side, which shows that after the 7808 was added (upside down), I used the inner rail for the positive side downstream of the 7808:


 
Homemade Modified Sine Wave Power Inverter(350/500w) on a Breadboar03



Finally, I am including a link to the You Tube video that shows the inverter in action.

You will want to read the text following the video, as ElectronicsNMore also added circuit inrush protection, a fan, and a low battery indicator. You can search the ElectronicNMore video channel for the design (and video) regarding circuit inrush protection.

Also in the video, he demonstrates his finalized project, using a both a hand held sander and high power garage light. You may notice in the video, he is using the 350 watt version of the schematic (by using IRF3205 mosfets). Nice to see a video of the inverter in action.

You Tube Video "Homemade Modified Sine Wave Power Inverter":
Schematic Reference

   Modified Sine Wave Mosfet Inverter Schematic by John Parfrey
 
Videos from electronicNmore:
 
   Homemade Modified Sine Wave Power Inverter(350/500w)
    
   Simple/Effective Solution To Inrush Current Problems

   Simple 120/240 VAC LED Power Indicator

   12V Lead Acid Battery Low Voltage Alarm Circuit 

   12V Lead Acid Battery Overdischarge Cutoff Circuit

  Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit

   Under Voltage/Over Voltage Cut Off Circuit (12vdc/120v/240v) (Video)

His temperature activated cooling fan (above) uses the bimetal sensor normally used with NiMH battery packs, available on Amazon and Ebay. Here's a link to an Amazon listing:

Amazon (Normally Closed??) "High Quality KSD9700 250V Bimetal 45 Celsius NC Temperature Control Switch Pack Of 10." 

Amazon (Normally Open??) "10 Pcs Bimetal Temperature Control Switch Thermostat 40C N.O TLRS9700



YouTube video link: 
Electronic Projects Circuits Blog Article:

   Battery voltage monitor circuit by LM339

Homemade Circuit Designs Just For You Blog:

   Under Voltage/Over Voltage Cut Off Circuit (12vdc/120v/240v) (Blog)


  

Thursday, November 20, 2014

100 Watt Inverter Circuit Schematic using Pulse Width Modulator IC SG3525 (my review)



100 Watt Inverter Circuit Schematic using Pulse Width Modulator IC SG3525

                                  (my review)

 Here's a nice little gem that I found on the circuitsgallery.com web site, designed by Khaleel.

 

 
12v to 230v Inverter Circuit Schematic using Pulse Width Modulator IC SG3525 by Khaleel

Fairly straightforward, and fairly easy to build. You have to watch for a few resistors that are 1/2 watt, some capacitors have strange terminology, and some of the symbols are explained in the text portion. So, be sure to review the article if you want to build this one.

 

I currently have this one running on the breadboard.

 

The design calls for a 12-0-12, 5 Amp transformer, but I only have a 4 Amp transformer, so mine is not quite to specifications. However, it still works. The Rt is adjustable if it is replaced with a preset or potentiometer. That adjustment was necessary (for me), due to my 4 Amp transformer. At any rate, the final result was that I was able to adjust to the 60 Hz frequency using a 4 Amp transformer and adjusting Rt as a potentiometer. (The 4 Amp transformer requires less resistance at Rt.)

 

The Pulse Width Modulation (PWM) automatically adjusts for powering devices with various power needs. I currently have it running from the breadboard, but I suspect I may build it with two outlets, or otherwise I would suspect that I should be able to use an extension cord with lights of various voltages.

 

Let me see, the only drawback of a circuit this straightforward is that the waveform is not a sine wave form, nor a modified sine wave form. Which means, it may be a bit harsh to use on sensitive electronic devices. I would only use it for lights.

 

Still, I am short on emergency lighting, and need some practice adding things like a fan and some circuit protection. So, I intend to build a finished version of this little one, simply for those reasons. 

 

Nicely done, Khaleel. I suspect this would be a quick build for most folks. This could be useful for emergency lighting, or for lighting the workshop. Thanks.

   

Reference:  

12v to 230v Inverter Circuit Schematic using Pulse Width Modulator IC SG3525

 



 

Sunday, November 9, 2014

Make a Solar AA Battery Charger by TL497 (my review)


   Make a Solar AA Battery Charger by TL497 (review)

This is a project to use a solar panel to charge a small battery, such as a NiMH battery in the 3V to 9V range, with mAH measuring between 1,000 to 2,000 mAH. It's just great to see that they have also included the PCB layout for you on this design. Something I don't see very often.



http://www.eleccircuit.com/make-solar-aa-battery-charger-by-tl497/


The TL497 integrated circuit is a fixed-on-time variable-frequency switching-voltage-regulator control circuit. It features frequency control and current limit sensing, among other things.
 

Make a Solar AA Battery Charger by TL497 from Electronic Projects Circuits


First things first, I have to point out that I am not using their circuit as designed.

The circuit calls for a 5V 100 mA solar panel, and I only have a 6V, 1 watt solar panel available. Secondly, I am trying to use it to charge 4 AA NiMH batteries, rated 2500 mAH, which is also not to specifications. Third, it calls for a 40 uH inductor. I don't happen to have a collection of inductors, but I do have a few toroids available.

Be aware that I am not using this circuit as designed, so your results may be different.

Even with my changes, it looks to be working for me. However, I hope to be performing more testing on this unit.

The circuit seems to work well for me using AA batteries when I cover the toroid about 4 times, or for about 90 turns of 22 guage wire.
I don't have a micro Henry meter, so I cannot specify what I have in those units at the moment.

I am testing in ambient light, such as what you might get in the shade, or when indoors.

At the moment, this one appears to perform better than the Solar Charger Circuit Project, and also appears to out-performs the 3 Volt to 9 Volt Converter (with either a 4.5V solar panel or a 6V 1 watt solar panel (that I have posted elsewhere). That is, sometimes it appears to perform better than the 3 Volt to 9 Volt Converter, sometimes not.


I will be doing more measurements, and trying to figure out the best way to test even though I don't have everything to specifications.
 

Previous Articles:

 Solar Charger Circuit Project (my review)

  3V to 9V Conerter (my review)
   
Currently testing for parallel charging, which is typically harder to do than charging in series.
You may get better results from charging in series.

I will also be looking at variations, such as number of turns on the toroid, etc.



Update Sep 7, 2015:

I have yet another AA charging circuit posted here:


Solar Charger Circuit Project (my review)


                        Solar Charger Circuit Project


Take advantage of the sunlight and use it as a power source. It can at least save on electricity prices continuing to rise, or be of help on a camping trip, or while traveling.

The Circuits Schematics Electronics blog has a schematic of simple power plant can be created and used to fill your motorcycle battery, your ebike battery, or for emergency lights:



     http://circuitschematicelectronics.blogspot.com/2012/06/solar-charger-circuit-project.html



The circuit is designed to charge a 12 volt battery, but I wanted to see if it would simply charge 4 AA NiMH batteries (4 to 5.6 volts).

So, I went about putting it together on a breadboard.

  
 
Solar Charger Circuit Project from Circuits Schematics Electronics


I was curious if I could use this to charge 4 AA NiMH batteries, and was not disappointed.
Therefore, first off, I have to point out that I am not using their circuit as designed.

Notably, the specifications call for a 4V, 200 Amp solar panel, and a ferrite rod. I did not use either. I do not have the BY207 (Diada 5 Ampere diode). Nor am I using a 12 volt battery.

You can use a ferrite rod, possibly from an old AM radio.  I don't have a ferrite rod, but I thought I would try it with toroids, as toroids I do have.

Also, the circuit calls for a 4V, 200 Amp (total) solar panel, but I only had a spare 6 volt, 1 watt solar panel.


The specifications call for a BY207 (Diada 5 Ampere diode), which I do not have.
Instead, I tried a 1N4735A, 6.2V, 1 watt Zener diode.

 The circuit is designed to charge a 12 volt battery, but I wanted to see if it would simply charge 4 AA NiMH batteries. So, I went about putting it together on a breadboard.

However, I did get some results. At first, it did not appear to generate enough voltage or amps for my AA batteries. With a little experimentation with the number of windings on the toroid, I was able to get some decent figures for the voltage required to charge my AA batteries.

It appears to respond to an increase in the number of turns of wire on the toroid.
I have 22 guage wire available, and a blue toroid from Digi-Key. The toroid spec out as Inductance Factor of 5.46┬ÁH and Permeability of 4300.


The circuit seems to work well for AA batteries when I cover the toroid about 2 times, or for about 60 turns of 22 guage wire. I don't have a micro Henry meter, so I cannot specify what I have in those units at the moment.

Again, this is not how the circuit was designed to be used, but I was happy to see that I could modify it for this purpose.


Currently, I am testing in ambient light, such as what you might get in the shade, or when indoors. This one appears to under perform both the use of the IC 497, and also under performs the 3 Volt to 9 Volt Converter that I have posted elsewhere.



However, it is much simpler to build, it is using parts that are generally available, and again, I am not using the circuit as designed. But, I was happy to see it respond to charging AA batteries.


Previous reviews:

   Make a Solar AA Battery Charger by TL497 (my review)

  3V to 9V Converter (my review)



Currently testing for parallel charging, which is typically harder to do than charging in series.
You may get better results from charging in series.

I will be looking at variations, such as number of turns on the toroid, serial vs. parallel charging, ambient light, etc.


Update Sep 7, 2015:

I have yet another AA charging circuit posted here:


300 Watts PWM Controlled, Pure Sine Wave Inverter (my review)

  300 Watts PWM Controlled, Pure Sine Wave Inverter

There are so few pure sine wave inverter designs available, I just had to put this one together on a breadboard:
 

  http://homemadecircuitsandschematics.blogspot.in/2013/10/modified-sine-wave-inverter-circuit.html

This one appears on the pages of Homemade Circuits Just For You, but is designed by an avid reader of that blog, Mr. Theofanakis.

It certainly is a sign wave form, as you can see on the graph on the web page.

This one is put together using the 4017 integrated circuit.

I have not run this one through it's paces yet, and have not tested under heavy load.

However, I have tested on the breadboard with a 4 watt bulb. Unfortunately, the frequency is my concern. I found it hard to hold the frequency at a constant rate, so I have put further testing and completion of this on my waiting to do list.



300 Watts PWM Controlled, Pure Sine Wave Inverter Homemade Circuits Just For You

Here, I have the inverter with no load:


300 Watts PWM Controlled, Pure Sine Wave Inverter with no load


Here, I have the inverter running a 4 watt light bulb:


300 Watts PWM Controlled, Pure Sine Wave Inverter with 4W load




You can click on the images to enlarge, where you might notice that the frequency is getting away from me.


I still have the need to review my parts, and ensure that they are to specifications, etc.

For the moment, the Pure Sine Wave Inverter Using the 4047 (100 Watts, designed by Mr. Swagatam Majumdar) is the one I would like to concentrate on. The initial performance (of the frequency and sine wave) from the 4047 appears to be much better than this one, including after modifications to 250 Watts (
or more by using 4 mosfets / 2 in parallel,etc.).

Dark Sensor on a Breadboard (review)

                  Dark Sensor on a Breadboard
                                                         (review)

Here's a nice little Night light Circuit for you:



               http://www.buildcircuit.com/dark-sensor-on-breadboard/

I use it with an Ultra High Brightness Blue LED (10mm), available from Radio Shack.
That produces enough light to navigate through a room at night, without turning on any other lights.

With a minor modification, it can be used with 4 AA NiMH batteries (4V to 5.6V), although the specifications call for 6V. It has been working very well for me. Other schematics for 6 volt and (only) one transistor variations are available from the buildcircuit.com web site.

In order to use the circuit with 4 AA batteries, just bump up the resistors to all be 1K Ohms.
The 4 AA NiMH batteries last about a few days, so I have found it useful to add a low voltage indicator.






 
Dark Sensor on a Breadboard from http://www.buildcircuit.com/dark-sensor-on-breadboard/



Low Battery Indicator Using Two Transistors




A nice low battery indicator circuit is available here:

http://homemadecircuitsandschematics.blogspot.com/2013/05/low-battery-indicator-circuit-using-two.html


Conveniently, this circuit provides a low voltage circuit that works well with the above automatic night light, using 4 AA NiMH batteries.

It has an adjustable preset (roughly, a 50K potentiometer), which can be set for a variable number of batteries.

The web page also includes instructions for reversing the circuit to use it as a high battery indicator. The high battery indicator could be useful of you also charge the AA NiMH batteries.

Another one of my favorites from Mr. Swagatam Majumdar.



  



 
Low Battery Indicator Using Two Transistors from Homemafe Circuits Just For You