Monthly Archives: August 2005

TL494- Power supply for VFD

Typically in self made small hardware (DIY), power from mains transformed and rectified using simple wall “cube”. But this cube produces typically 12V. A bit too low for VFD. If I would like to use some higher voltage cube for … Continue reading

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TL494 – magic chip, Part 6

While testing this device, do not overload, do not load asymmetrically. For checking your system, remove nixie and load secondary winding of transformer with simple resistor. Download small (~500kb XVid AVI): with oscillograms. And now take a note, that on … Continue reading

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TL494 – magic chip, Part 5

Everything is working with simple passive mosfet drive. But if we increase switching frequency or place powerful mosfet (or even several mosfets)? There is no load in gate circuit, but there is gate capacitance. And if we need fast switching … Continue reading

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TL494 – magic chip, Part 4

Now let’s make some high voltage! As the schematics is done on the breadboard, I can’t produce high power application. This is because of very long wires used in the experiment. Also there is no any heat sink on the … Continue reading

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TL494 – magic chip, Part 3

the output of TL494 is quite weak, and we want more power. So we need some powerful transistors attached. The most easy to use (and very easy to get- from old computer motherboards) are n-channel power mosfets. We must invert … Continue reading

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TL494 – magic chip, Part 2

Now let’s speak about the pins. GND (pin 7) and Vcc (pin 12) are usual power pins. Max Vcc is about 40V. RT (pin 6) and CT (pin 5) are used for setting clock (1 … 300kHz). The frequency of … Continue reading

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TL494 – magic chip

From time to time, in newsgroups, in www forums and in www pages, people speak about converting DC to DC, or DC to AC, charge-pumping, building inverters (step up, step down converters) for various devices. From high power car audio … Continue reading

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