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Powering a CRT Fly back with 120VAC

PixelGeek
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Go to solution Solved by PixelGeek,
28 minutes ago, Unimportant said:

The transformer winding will still look like a dead short. The light bulb will light with full intensity and nothing much else will happen.

So, you're saying the transformer wouldn't output anything?

Soooooo, I've liberated a flyback transformer from an old CRT and would like to have a high voltage transformer for projects. 

 

Over all the videos I've watched, they say to power the primary with 12VAC (most likely from a halogen lamp transformer), for ~20,000VAC output on the secondary.

But that got me in to thinking, these sparks look pretty weak, what if I just plugged in to the mains and put 120VAC through the primary?

 

Electrical fire? Breaker Pop? Magic blue smoke? Any thoughts? I actually have two flybacks, so i can experiment on one of them. 

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13 minutes ago, PixelGeek said:

Soooooo, I've liberated a flyback transformer from an old CRT and would like to have a high voltage transformer for projects. 

 

Over all the videos I've watched, they say to power the primary with 12VAC (most likely from a halogen lamp transformer), for ~20,000VAC output on the secondary.

But that got me in to thinking, these sparks look pretty weak, what if I just plugged in to the mains and put 120VAC through the primary?

 

Electrical fire? Breaker Pop? Magic blue smoke? Any thoughts? I actually have two flybacks, so i can experiment on one of them. 

Breaker pop.

 

The flyback transformer is designed for frequencies far greater then the 60Hz mains frequency. It's relatively low inductance would make it look like a dead short @ 60 Hz, causing the breaker to pop.

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7 minutes ago, Unimportant said:

Breaker pop.

 

The flyback transformer is designed for frequencies far greater then the 60Hz mains frequency. It's relatively low inductance would make it look like a dead short @ 60 Hz, causing the breaker to pop.

What if I were to put it in series with a lightbulb, or a fan, to add some resistance?

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18 minutes ago, PixelGeek said:

What if I were to put it in series with a lightbulb, or a fan, to add some resistance?

The transformer winding will still look like a dead short. The light bulb will light with full intensity and nothing much else will happen.

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28 minutes ago, Unimportant said:

The transformer winding will still look like a dead short. The light bulb will light with full intensity and nothing much else will happen.

So, you're saying the transformer wouldn't output anything?

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27 minutes ago, PixelGeek said:

So, you're saying the transformer wouldn't output anything?

Depending on the transformer, if you put a light bulb in series with the primary, it's possible that some small stray voltage will be induced in the secondary. A couple tens of volts, perhaps 100V, but nothing worthwhile considering the aim is to generate several kilo volts.

 

It's designed to operate at a CRT's horizontal frequency of around 15 KHz. At 60 Hz only a tiny amount of energy is transferred before the core saturates each cycle.

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