Need some help with school project

Discussion in 'The Projects Forum' started by drew93, Mar 29, 2011.

1. drew93 Thread Starter New Member

Mar 29, 2011
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0
Well what we are doing is making a small scale power grid with 2 renewable energy sources. My job is to make the connection between the two. Right now I am having trouble building a DC to AC circuit that connects from the renewable side to the grid. We are receiving 5 volts 25mA from the RE side and I need to convert that into 5v rms 60hz to the grid side. Could anyone help me find a circuit that would help me meet those requirements? Thank you.

2. Wendy Moderator

Mar 24, 2008
20,772
2,540
A simple 555 circuit could do the latter. You didn't specify if you wanted a sine wave or not, which will increase complexity. You mentioned RMS, which hints you do want a sine wave. In this case I think I would go with a PWM circuit and a simple sine wave oscillator, as this will be a lot more efficient than a simple analog amplifier after an oscillator.

5V RMS (sine wave) means you will need a 14.14 P-P signal. Unless you have a transformer (a valid assumption) you will need a 15VDC power supply.

3. drew93 Thread Starter New Member

Mar 29, 2011
6
0
We do need a sine wave.Could you point me to a pwm circuit that I could use as there are tons out there. Also where would I find the correct sine wave oscillator circuit? So I need a transformer I assume since I do not have a power supply. We are getting power from our renewable energy source which is only 5vrms

4. Wendy Moderator

Mar 24, 2008
20,772
2,540
You'll need a sine wave generator.

Bill's Index

Sine Wave Oscillators A PDF abstract by TI

It is possible a simple oscillator will fit your needs. I'd lean towards the Bubba oscillator myself, though I've never used it (yes, that is its name).

As for a transformer, you can roll your own using a simple toroid core and magnet wire. Since your power requirements are pretty modest this is easy to do.

If you want me to try for something more advance I can sketch something up. This will keep you busy for a day or so though.

A work in progress...

AC/DC Inverters